Down Syndrome and Folate Metabolism

The other day I received a comment from Sheila on my post related to MTHFR mutations and fetal cardiovascular malformations. She reported that she had had a history of recurrent pregnancy losses (x 4) and during her ‘work-up’ for the same was found to have a low-positive level of IgM anticardiolipin antibodies and was also found to be homozygous (two copies) for the C677T MTHFR mutation. Her “homocysteine levels are normal” (but I am not told if these were done before or after she began folic acid supplementation) and karyotyping (presumably hers and her partners) “also came back normal.” She finally succeeded in carrying a pregnancy, after being treated with Foltex, prenatal vitamins, and Lovenox, only to deliver a baby at term with Down syndrome (trisomy 21). She notes that the baby “has no cardiac problems and is actually developing very well.” Her primary question to me was “Are these blood disorders (MTHFR mutation and Down syndrome) related?”

Well, Sheila, thanks for writing and you get the prize for the most intriguing question of the month! First let me review why folate metabolism and the methylenetetrahydrofolate reductase (MTHFR) gene are important. MTHFR is an enzyme that requires folic acid to convert homocysteine to methionine (an important amino acid) and when this does not occur, homocysteine can accumulate. As we briefly discussed in that previous post, when this occurs in a developing embryo as the result of either folate deficiency or certain mutations in the MTHFR gene, this may have a ‘toxic’ effect, increasing the risk for neural tube defects and certain cardiovascular abnormalities. This same biochemical pathway is also essential for the production of a substance called S-adeneosyl methionine that is an essential intermediate in pathways that add methyl (CH3) groups to nucleic acids (DNA; RNA), proteins, neurotransmitters, and phospholipids, a process that plays an important regulatory role in the biological functions of each of these.

Down syndrome results from the presence of 3 copies of chromosome 21. In 90-95% of cases, the extra chromosome is maternal in origin and results from a failure of normal chromosomal segregation (nondisjunction) during meiosis. This produces one egg (ova) that has 24 chromosomes (22 different chromosomes + 2 copies of chromosome 21) and one egg that has only 22 chromosomes (with no copies of chromosome 21). If the first egg is fertilized by a normal sperm containing 23 different chromosomes, we end up with a baby that has 47 chromosomes rather than 46, and in this case Down syndrome. If the second egg is fertilized, the embryo that is produced has only 45 chromosomes and is nonviable if it has only one copy of chromosome 21 (from the father). Although the risk for trisomy 21 increases with maternal age, most children with Down syndrome are actually born to women less than 30 years of age.

“On the basis of evidence that abnormal folate and methyl metabolism can lead to DNA hypomethylation and abnormal chromosomal segregation,” James and colleagues (Am J Clin Nutr 1999;70:429-30) hypothesized in 1999 that young women with the most common MTHFR mutation (C677T) might be at greater risk for having a baby with Down syndrome than their peers who do not have the mutation. In this study, they evaluated the frequency of the C677T mutation, plasma homocysteine levels, and lymphocyte methotrexate cytotoxicity as indicators of functional folate status in 57 mothers of Down syndrome children and 50 matched controls. Findings of significantly higher levels of plasma homocysteine and increased sensitivity of lymphocytes to methotrexate cytotocity in the women with Down syndrome babies supported their hypothesis that abnormal folate and methyl metabolism might contribute to the risk for trisomy 21. Indeed, the women with the C677T MTHFR mutation in this small study had a 2.6-fold higher risk for having a baby with Down syndrome than those who did not.

A subsequent study published by Hobbs and colleagues the next year (Am J Hum Genet 2000;67:623-30) confirmed the preliminary results above. In a cohort of 157 women with Down syndrome babies and 150 matched controls, these investigators not only looked at the prevalence of the C677T MTHFR mutation (technically ‘polymorphism’), but also the prevalence of a common mutation (A66G) in the methionine synthase reductase (MTRR) gene, another enzyme essential for normal folate metabolism. The presence of the C677T MTHFR mutation was associated with a 1.9-fold greater risk, the presence of the homozygous A66G MTRR mutation a 2.57-fold risk, and the presence of both polymorphisms a 4.08-fold risk for having a baby with Down syndrome….(to be continued)

Labels: Down syndrome, folate metabolism, folic acid, MTHFR, nondisjunction, trisomy 21

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MedSkool Grand Rounds 3.36- Thanks!

Many thanks to the folks at MedSkool for including my post on "Contraception - A Basic Human Right" in this week's Grand Rounds 3.36 offering. Time has proven that neither abortion nor "just saying No" to sex is an acceptable solution to unplanned/unwanted pregnancy. Our best hope lies in sex education and contraception, but our country sorely lags the rest of the world in these areas.

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Percutaneous Umbilical Blood Sampling (PUBS)

In several previous posts, we addressed issues related to invasive diagnostic fetal testing, covering amniocentesis (early and midtrimester) and chorionic villus sampling. I got side-tracked by the ACOG Meeting in San Diego and just remembered that we had never gotten around to a discussion of the other common (though much less so than amniocentesis or CVS) invasive (and at times, therapeutic) procedure, percutaneous umbilical blood sampling (PUBS), otherwise known as cordocentesis or funipuncture.

This, quite simply (but technically tricky), involves the placement of a needle into the umbilical vein to remove fetal blood for a variety of testing purposes such as: chromosomal analysis; genetic studies; hemoglobin analysis (hemoglobinopathies); fetal anemia; platelet count; assessment of fetal acid-base status; fetal infection; coagulation system abnormalities; immune deficiencies. It is commonly used when rapid (48-72hr) and precise fetal chromosomal studies are indicated; in the definitive assessment of anemia under conditions of isoimmunization or parvovirus infection (and as a route of intrauterine transfusion if anemia is confirmed); in the evaluation of thrombocytopenia (= low platelets) resulting from either autoimmune or alloimmune (analogous to Rh-disease) conditions; in the evaluation of fetal hydrops; and, in the confirmation of fetal infections.

PUBS is performed under aseptic conditions and direct ultrasound guidance, much like amniocentesis. Without going into great detail, a slightly larger bore needle is often used than that used with amniocentesis, especially if the procedure is being done for suspected fetal anemia and a transfusion via intravenous access is warranted. When technically feasible, we prefer to access the umbilical vein within 1-2 cm of its placental insertion site. Unlike with amniocentesis, many of us actually prefer to go through the placenta to get to this site. This provides a more stable site for insertion than free cord floating around in the amniotic fluid, improves the prospects for success and probably reduces the risks of the procedure. (Fetal blood sampling can at times also be done directly from the baby, the most common sampling sites being the intrahepatic vein and the fetal heart, but special preparations and precautions must be taken under these circumstances and do not warrant discussion herein).

Although at times the fetal condition might justify earlier evaluation, most fetal blood sampling procedures are done in babies that are 23 weeks or beyond. Since we now consider almost all babies at this gestational age potentially viable, it is recommended that the procedure be performed at an institution that can handle extremely premature babies, and/or babies that may be compromised by the medical condition that led to the PUBS, and at a location in which an emergency cesarean section can readily be performed if a complication arises during or in the immediate post-procedure period.

The most common complications include fetal bradycardia (slow heart rate) during the procedure, hemorrhage or obstructing blood clot at the needle insertion site, and intrauterine infection. Fetal bradycardia is often transient and its mechanism is unclear, but it may be related to spasm in the muscles of the uterine arteries if these were inadvertently punctured during the procedure. Prolonged bradycardia is more common, and more ominous, if it occurs when a baby is severely anemic, hypoxic, acidotic, hydropic (in heart failure), or is hemorrhaging uncontrollably from either the umbilical vein or an umbilical artery. If this cannot be corrected by our typical intrauterine resuscitative measures, immediate delivery may be indicated if the baby is at a gestational age where viability is possible.

Significant fetal hemorrhage from the needle insertion site is a relatively uncommon event; however, it is more likely to occur when the baby has low platelets as may be found in autoimmune, alloimmune, or parvovirus-induced thrombocytopenia. Of these, the greatest risk is in alloimmune thromobocytopenia because the platelet counts are often dangerously low and the platelets that are present may not function normally in clot formation. Babies affected by alloimmune thrombocytopenia are also at great risk for intracranial hemorrhage remote from the labor and delivery process.

In my experience, introduction of infection at the time of the procedure, either from maternal skin bacteria or blood borne organisms such as HIV, CMV, and hepatitis viruses, is a very uncommon event. Rupturing fetal membranes also occurs infrequently, but slightly more often than with amniocentesis alone. Risks for any of these complications rises with the length and complexity of the procedure, the larger the bore of needle used, and maternal obesity.
There are theoretical risks of PUBS to the mother such as causing sensitization to fetal blood cells or platelets, causing damage to internal organs, introducing infection, or causing bleeding, but these are also very uncommon. Probably the greatest risk is that of an emergency cesarean section if this is required to manage a fetal complication.

Procedure-related fetal loss rate is difficult to ascertain but is probably in the range of 1-2% and again is related to the complexity of the procedure and the fetal problem that led to the procedure being recommended in the first place. Babies with an indication for PUBS may be critically ill and, for example, those with hydrops, especially nonimmune hydrops, may not be salvageable regardless of any interventions attempted. It is difficult to consider a loss of one of these babies to be a ‘procedure-related event’ when their morbidity is so high at the outset.

PUBS is the riskiest and most challenging of the more common invasive diagnostic procedures we perform, but it is usually reserved for the most severe fetal compromise as well. In recent years, one of the more common indications for PUBS, screening for fetal anemia, has been replaced by the noninvasive Doppler flow assessment of peak systolic velocity in the fetal middle cerebral artery. PUBS is now only done under these circumstances when a significant fetal anemia is suggested by an abnormal Doppler flow result. Also, with the recent advances in genetic and molecular technologies, many of the studies that required PUBS in the past can be performed simply on amniotic fluid and/or the cells contained within it. And, quite likely, many of these studies will be able to be performed on the small amounts of fetal cells and DNA contained in maternal blood specimens as these technologies continue to advance, further reducing the need for these invasive studies.

Labels: amniocentesis, CVS, isoimmunization, percutaneous umbilical blood sampling, PUBS

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Falling Folic Acid Levels Portend Problems

A few weeks ago, I attended the Medicaid Commissioner’s Perinatal Task Force meeting in my home state of South Carolina. A featured presenter at that meeting was Dr. Roger E. Stevenson from the Greenwood Genetic Center who reminded us of the need to increase our vigilance regarding dietary intake of folic acid in women of childbearing age. Our part of the country has the dubious distinction of being one of the hotbeds for neural tube defects (spina bifida; anencephaly; encephalocele) in the U.S. But medical leaders from our state, at the forefront, Dr. Stevenson and colleagues, also played a key role in convincing the FDA in the late 1990’s to mandate folic acid supplementation in foods, partly, as the result of the successes experienced with such programs in our own state earlier in the 1990’s.

In 1992, 1 out of every 500 babies conceived in the State of South Carolina had a neural tube defect (NTD). By 2004, that number had been reduced to only 1 in 1300. It is estimated that with adequate folic acid supplementation, and programs designed to identify women at increased risk based on family or previous obstetrical histories, at least 50% of those NTDs could have been prevented as well. The value of supplementation was most clearly demonstrated here in the follow-up of women who had previously had a baby with a neural tube defect. Among the 362 who were placed on folic acid above that obtained by diet alone, none had a subsequent baby with an NTD. Of the 62 who did not take a supplement, 3 (5%) had another child with an NTD. This is consistent with the worldwide baseline recurrence risks of 3-5% (the risk is 7-10% if there have been two affected babies).

Dr. Stevenson estimated that with adequate folic acid prior to conception and during the first trimester (remember, the neural tube is completely closed by 28 days after conception, only two weeks past the first missed menstrual period), 60 NTD babies could be prevented each year in our state. Twenty-five of those babies would have such severe defects that they would succumb early, however, of the 35 who survived, the average cost for care of these children is $425,000, or $15,000,000 added to health care costs each year! If one considers that certain classes of congenital heart defects (the most common abnormalities found after delivery), and perhaps other abnormalities such as cleft lip and palate, might also be prevented in part by folic acid supplementation, the overall savings to health care costs could easily be 2-3 times that.

Despite the success of dietary education and folic acid supplementation programs, a recent concern raised in the CDC’s Morbidity and Mortality Report of January 5, 2007, is that surveys indicate blood folate levels have actually been decreasing in recent years. It was pointed out that with folic acid supplementation of cereals, grains, and flours, median folic acid levels in women aged 15-44 years increased from 4.8 ng/nL during 1988-1994 (presupplementation) to 13.0 ng/mL in 1999-2000. Between then and 2004, there has been a decline each year and in every ethnic group. The largest percentage decrease was noted in non-Hispanic whites (from 13.4 down to 11.3 ng/mL), but of greater concern is the decrease in ethnic groups that entered the 21st century with suboptimal levels to start with (non-Hispanic blacks going from 10.0 to 8.5 ng/mL and Hispanics from 11.1 to 10.0 ng/mL).

Reasons for this are not entirely clear. It has been hypothesized that the obesity epidemic may require that we reevaluate the adequacy of current recommendations for supplementation. Others have suggested that the “low carb craze” has reduced the intake of grains, flour, and cereals that are the foods primarily ‘supplemented’ by FDA mandate. Regardless, the overriding concern is that if the current trend continues, we run the risk of losing all the ground we have gained in reducing the serious and debilitating birth defects that are preventable by adequate nutritional intake of folic acid.

The bottom-line is that all women of childbearing age (whether or not you are anticipating a pregnancy) eat a healthy diet that includes foods such as fortified breakfast cereals, green leafy vegetables, broccoli, orange juice, black beans, peanuts, enriched breads and pasta. In addition, it is strongly recommended that women take a daily multivitamin supplement that contains at least 400 micrograms of folic acid, especially, if they are considering or trying to get pregnant. If a woman has previously had a baby with a neural tube defect (or any other abnormality that might be preventable by folic acid), she should take 4000 micrograms (4 mg) of folic acid daily prior to conception and during the first trimester of pregnancy.

Labels: congenital heart defects, folic acid, neural tube defects, NTD

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Blogging - Reflection of Eight Months Online at Healthline

This week’s Grand Rounds 3.35 is going to be hosted by impactEDnurse.com. The challenge to the submitters was to “take a journey back through the narrative of your posts and pick out a story that you consider to be one of your best. Maybe it is a story that particularly moved you, or a topic that really gets your juices flowing. Perhaps you have written something that had special meaning to you. Or covered a topic you consider of great significance. Or you may have produced something you feel is superbly entertaining. I am looking for that quintessential post that you consider a representation of your true voice as a medical blogger. Take your time and choose well.”

So, I decided to review some of what I had written since August of last year. I was quite surprised by the number of posts (now more than 100, not to mention all of the ‘responses to comments’, several of which could have been posts on their own), diversity of topics and variety of approaches I have taken to convey my thoughts on this site. I related stories that had “moved” me, topics that had gotten my “juices flowing” and had “special meaning” to me, some that covered important, if not significant, issues, and some that were actually “entertaining.” I honestly asked myself on several occasions as I was reviewing these, “Did I really write that?”

Interestingly, I have always held writers in very high esteem and never considered myself to be much of one; in fact from an early age, writing terrified me! If it had not been for my father, who was quite gifted at conveying his thoughts in prose, I probably would have never gotten through 7th grade English. And, for those of you who have stuck with me from the start, you already know that I took on this role on request of Dr. Paul S. Auerbach ("Medicine for the Outdoors"), an old friend of mine from college and medical school, with some trepidation and seriously wondered if I would be up to the task.

What I have learned is that I thoroughly enjoy doing this, even if my ‘styles’ are as varied as the weather (or, is it schizophrenia) as I search for my “true voice.” Writing in this format has given me the opportunity to reflect on my experiences, gather inspiration from the patients who have entrusted me with their care and blessed my life, and express opinions outside the formal structure of the ‘peer review’ process. The whole experience has been a catharsis of sorts and has added considerable meaning to my life and role as a physician.

It has taken me many years to accept the teaching that the hardest part of writing is ‘just getting started’, putting the first words and thoughts down on paper. Writing is truly a ‘process’. It is the ‘gifted’ and exceptional individual who can ‘get it right’ the first time. Accepting this limitation was a major obstacle to be overcome for me (my ego would accept no such limitations). Part of my ‘developmental delay’ in this regard was my perceived inefficiency of such a process and that was exacerbated by my inability to type – I still get by with just two fingers, albeit fast fingers! When I was younger, the thoughts that would spill from my brain onto paper always seemed disorganized (and they were at first) because I am one of these folks whose mind races (ADHD???), knowing A is connected to Z, but challenged by the process of breaking down the steps into B through Y (lots of physicians seem to be put together that way!). Add to that the impediment of having to commit and rearrange, quite laboriously for me, those words in text format was, admittedly, a challenge, limited my productivity, and delayed my emergence as an author of any sort. Indeed, if it wasn’t for the development of word processors, lots of my thoughts would probably still be stuck bouncing around inside of my head!

Anyway, after reviewing my work over the past year, I selected and passed along a couple of my posts to impactEDnurse.com for Grand Rounds 3.35 consideration. One reflected my serious side and one my sense of humor. Were they “quintessential?” I don’t know! I think that is up to you, the readers to decide. In fact, sometime it would be great fun to have the readers make THEIR selections from the blogosphere for a Grand Rounds compendium!

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Contraception - A Basic Human Right

Outside the San Diego convention center, a group of ‘protesters’ continually harangued attendees at the recent ACOG Annual Meeting as they crossed the street to return to their hotels. The protesters carried large placards, displaying the body parts of babies, and chastised the attendees about the Society’s position, generally (not all members concur), supporting a woman’s “right to choose.” One of the protesters, a woman, grabbed my arm, read my name tag and said, “Ken, don’t you care about the babies?” A surge of intense anger came over me. I looked her squarely in the eye and told her that “I have spent the last 28 years of my life caring about women and their babies and if we had a government that didn’t treat women as second class citizens, a government that supported providing adequate education regarding human sexuality, reproduction and responsibility at an early age and through the school years, and a government that made it possible for men and women to have ready access to contraception, there would be fewer unplanned pregnancies and unwanted babies and abortion would become a thing of the past. You are wasting your time here. Take that message and your signs to the White House.”

The sobering fact remains, that in a country with the most advanced technology in the world, the resources that could provide adequate education, nutrition and health care to every citizen (if we so chose), 50% of all pregnancies are unintended; teen pregnancy rates have taken a turn upward. As the result, the projected population increase in the U.S. between 2000 and 2050 is in the range of 32%, on par with rates in Asia and Latin America! In real terms, this translates to a population of about 400,000,000 within the next 40-50 years. In contrast, developed nations in Europe are projecting a 10% decline in population over the same time frame.

Our world has limited resources, and no country can sustain a high rate of population increase for long without suffering a deleterious impact on its ‘standard of living.’ I do not understand how or why our leaders choose to ignore that basic fact. In 1994, the International Conference on Population and Development recognized reproductive control as a “basic human right” and a necessary first step to alleviating poverty and raising worldwide educational levels and health status. In 2004, the World Health Organization reaffirmed this position and further concluded that those rights include:

• Access to the highest standard of health care
• Individual control of sexuality
• Personal choice of spouse
• Access to all relevant health information
• Freedom to choose the number, spacing, and timing of children

Yet, the U.S. is the only member of the United Nations that to this day refuses to embrace this theme.

More disturbing to many of us, our country seems to take as many steps backward as it does forward with regard to contraception and human sexuality. To illustrate this point, during a news conference on these issues at the annual meeting, Dr. Vivian Dickerson, past president of ACOG, mentioned the March 2007, 8th Circuit Court of Appeals’ ruling that employee health plans do not have to include contraceptive coverage for their employees. The short-sightedness of this ruling cannot be overemphasized in view of the fact that such coverage would be a “negligible cost to employers” considering the “$19 billion annual expenses directly related to unintended pregnancy.”

Dr. Kathryn Moore, ACOG Director of State Legislative and Regulatory Affairs, also pointed to the inequities of health care coverage and the second class status of women. She related that “22 states do not require insurers to cover contraception; however, these same insurers voluntarily cover drugs like Viagra,” suggesting “that male sexual dysfunction is a more pressing public health concern than unintended or unwanted pregnancy.” By the way, a month’s supply of Viagra probably costs 5-10 times what it does for a pack of oral contraceptives. So tell me, why does religious and moral opposition to contraception only apply to women…????

Labels: contraception

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Grand Rounds 3.34 at Medical Humanities Blog

Thanks to Dr. Daniel Goldberg at Medical Humanities Blog for including a link to my "Mother's Day Thoughts" in this weeks Grand Rounds 3.34. Love ya', Mom!

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Mother's Day Thoughts

On Wednesday, May 9, 2007, Kenneth L. Noller, MD from Boston was sworn in as the 58th president of the American College of Obstetricians and Gynecologists. During his inaugural address, he reminded the audience to be cognizant of our past, the long hours spent in training, the long hours many of us still work, especially those practicing obstetrics, and the fact that many of us have “put our families second” to care for our patients over the years. But, he also called upon us not to live in that past and to embrace the opportunities for change, now and in the future, to bring balance to our lives and, by demonstrating that as a possibility, to encourage bright, young men and women to consider OB/GYN as a career. He also reminded us that “our specialty is unique, it is the only gender specific medical specialty,” of the “great privilege we have to care for women,” and of the great privilege we must honor and accept in our continuing role as the “champions of women’s health care.”

Today is Mother’s Day. The week’s end rain finally stopped and the sun came out and since it is supposed to remain sunny for the next several days, I decided to ride my motorcycle to the hospital. I love riding my motorcycle to work early in the morning. There is usually no traffic, the sounds and rhythms of the engine and the morning light have a soothing effect on my psyche, and the necessity of remaining focused on the task of riding (in the constant vigilance required for self-defense!), always clears my head and prepares me for the work at hand – in this case, the next 36 hours of resident supervision and other patient care activities. While riding, though, I did take the liberty of letting my thoughts wander back to some of Dr. Noller’s words and to thoughts of Mother’s Day.

Dr. Noller not only said that we have often “put our families second,” but that this was “as we should have.” I was taken aback by this statement at the time, and still do not, entirely, agree with it. I know my wife often feels that I have put the family second, but I have a different perspective. I guess I have always looked at my patients as my ‘extended family.’ Rather than putting one above the other, I have tried to handle both as equals, with the ever challenging task of ‘setting priorities.’ My patients don’t always come out on top in those decisions. There have certainly been times, especially, when I was ‘the only show in town’ that the family responsibilities were temporarily placed on the back burner, but today, that rarely occurs. There have also been a few instances, even in recent years, where it was apparent that the faith and hope the patient placed in me as a provider were as important to the pregnancy outcome as any clinical skills that I brought to the table, not because I thought I could handle the situation better than any of my colleagues. Anyway, those were my first thoughts.

Next, I thought of my own mother. It is only with the clarity of age and my own life experiences that I have come to comprehend just what a remarkable person my mother was (and still is). As we were growing up, my mother was THE steady and constant influence in our lives. Although not a ‘single Mom’, between my father’s work during the day and his college classes at night, she was certainly the prototype for the same! There were six of us kids; I was the oldest. Although we did not have much in material terms, we didn’t know that; we had enough to eat, some clothes on our backs, and a wonderful church which was the circle of our ‘social’ activities. We were happy and we did have our dreams.

Then, during my sophomore year in high school, my father at age 36 started having seizures and was eventually diagnosed with a brain tumor. Between the tumor and its treatment, my father lost all capacity to work, to think analytically, and to take reasonable care of himself. My parents’ hopes and plans (my father was in law school at the time) for the future of our family were dashed in the blink of an eye. My mother had to go to work, pay the bills, help with homework, play chauffer for the three oldest children, and nurture the 3 youngest (my youngest sister was only two at the time). Somehow she juggled all of that and managed to take care of my dad, wash clothes every day, and rarely failed to have something prepared for dinner each night. Despite very hard times, she was always there for me, my brothers, and my sisters. We all did hang together, but she was the super glue and by her example, all of our lives were enriched. It is with great regret and not just a little embarrassment that I didn’t appreciate at the time the sacrifices she made for us.

I have learned that it is much too easy to take for granted the folks in our lives whom we see every day, and the situation with my mother was just that. She did so much for us and never once asked for anything in return. She ‘lost’ her husband, my father, at a young age, she stuck with him for the ten years that he lived after the diagnosis of his brain tumor, she never remarried, and she remains in the little house in New Jersey we moved to in 1956 (now living with my youngest sister and her family). In 1969, I left for college and in all the years since then, very little time has been spent with my mom; and, the many years have gone by much too quickly. Although every Mother’s Day is special, for some reason this year, I feel the need to let her know that I love her, I think of her often (even if I am not very good about calling), I thank her, and I know the contributions I have made to the lives of so many other women and their families over the years would not have been possible without the work ethic and the life’s lessons she taught me. Have a great Mother’s Day, Mom! Please come visit us soon…

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Time to Reevaluate Cesarean Section Techniques

The other day I attended a session entitled “Myths and Truths of Cesarean Delivery Technique” presented by Dr. Aviva Lee-Parritz from Boston Medical Center. The discussion critically evaluated the surgical techniques commonly employed to accomplish cesarean deliveries. C/sections are one of the most common procedures performed in this country (and probably the most common in women) and becoming more common every day. The bottom line is that we all do them, but the best approach to the operation has never been defined! When I trained (too many years ago), the operative approach had been accepted for many years and simply passed down from resident-to-resident. No one ever questioned the legitimacy of that approach. After all, it was described in Williams’ Obstetrics and wasn’t that written by divine inspiration?!?

To be fair, the technique was based in good surgical principles designed to minimize risks for bleeding and infection at a time when these were major concerns, prior to both blood transfusion and antibiotics. Indeed, the procedure most commonly used today (the low-transverse cesarean section – referring to a cross-wise incision in the uterus, regardless of the skin incision) has not changed much since it was first described by Kerr in 1926. Over the years, we developed specific guidelines for the type of skin incision (transverse, lower abdominal vs. vertical) that was made under specific circumstances; we usually ‘developed the bladder flap’ (incised the thin layer of peritoneum over the lower uterine segment and pushed the bladder down before incising the uterus) except in dire emergencies; we knew the type of uterine incision that was preferred (transverse or vertical) under specific circumstances; we reached into the uterus to remove the placenta after the baby was delivered and then wiped the uterine cavity clean; we closed the uterine incision in two layers; and, then reapproximated ‘like-to-like’ (closed the bladder flap, closed the peritoneum, closed the fascia, closed the subcutaneous layer of fat, and then closed the skin) to complete the operation. And, despite all those steps, most of us could perform the procedure in a woman having her first one in less than 30 minutes ‘skin-to-skin’.

About 15 years ago, a paper was authored by Dr. John Hauth that suggested closing the uterus in a single layer was just as good as closing in two, thereby reducing operative time and the ‘perinatal morbidity’ associated with prolonged procedures, mainly, blood loss, infection, and risk for deep venous thrombosis and pulmonary embolism. In other words, there did not appear to be any short-term risks to this approach and there might even be some benefits. Around the same time, other papers challenged the necessity of closing the peritoneum (the thin layer of ‘skin’ that lines the inner abdomen and covers the internal organs (i.e., the ‘bladder flap’ over the uterine incision as well as the peritoneum of the abdominal wall). Without critically evaluating the individual risks and benefits of omitting these steps, many practitioners jumped on the bandwagon of the ‘simplified cesarean section’ and began closing the uterus in one big layer, leaving the raw surfaces of the ‘bladder flap’ and uterine incision exposed, and stopped closing the peritoneum lining the inner abdominal wall. Although I was rather skeptical at the time that this was really the right thing to do (raw surfaces tend to increase the risk for adhesions (scar) formation), especially because we had no long term follow-up on these women with regard to subsequent deliveries, our residents loved it because there were fewer steps (although they never seemed to do the operation any faster than us old fogies did in our heyday when ALL the steps were performed), so we just sort of went along for the ride.

Well, in recent years, as the cesarean delivery rate has skyrocketed, vaginal births after cesarean section have diminished (significantly), and we are performing more and more repeat cesarean procedures (and threepeats, and fourpeats, and fivepeats,….). We are also encountering more and more complications secondary to the previous procedures (occult and overt uterine ruptures, dense adhesions, placenta previas, placenta accretas, cesarean hysterectomies…). It is becoming clear that revisiting what, why, and how we are doing cesareans, and systematically ascertaining the best approach to the entire operation is necessary. It is also likely that the approach I was taught, based on what was considered to be ‘good surgical technique’ (but no data) and passed on by tradition, and the current ‘minimalist’ procedure, also based on a limited amount of data compared to the total number of procedures done, are at opposite extremes and the ‘truth’ probably lies somewhere in between.

As Dr. Lee-Parritz pointed out, if we look at the information already available from various sources both in OB and other surgical specialties, we are well on our way to defining a better approach to cesarean section. Without going into details of the hows and whys, herein, her analysis of the literature supports the fact that we should continue to use prophylactic antibiotics perioperatively (probably best given prior to the skin incision); we can probably perform most cesareans through a transverse abdominal incision; we probably do not routinely need to develop extensively the bladder flap; the uterine incision can safely be widened by blunt dissection; the placenta should be removed by traction rather than by ‘manual extraction’ (to minimize blood loss and infectious morbidity); the uterus should probably be closed in two layers (at least for all women planning another pregnancy, although how that is best accomplished and even what suture should be used is yet to be decided; if no ‘bladder flap’ is developed, we probably do not need to close either the visceral or parietal peritoneum; we should reapproximate the subcutaneous tissues, especially in obese patients; and, we can close the skin anyway we want to, although most patients would prefer not to see sutures or have staples that need to be removed at a later time and, actually, seem to have less postoperative pain when the skin is closed in a running subcuticular (under the skin) stitch.

If these steps were routinely employed, we should be able to minimize short-term risks of infection, bleeding, length of procedure, and perioperative pain and perhaps put a dent in the long-term complications of uterine scar dehiscence and pelvic adhesions that increase the morbidity of a subsequent pregnancy for both mother and baby. Who knows, an improved technique might also reduce the subsequent risk of placenta accreta and cesarean hysterectomy (allowing women to have more and more cesarean sections!). Unanswered questions could be readily addressed by a few well-organized multicenter research studies (in view of the huge total number of cases being performed each year, both first time and repeat procedures). We should be able to decide upon the best technique for closure of the uterus, the best suture to use under specific circumstances, and the best approach to employ with regard to closure of all the other body layers we went through to get the baby delivered.

Labels: cesarean section, delivery

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ACOG Annual Meeting - San Diego - "President's Program" continued...

…The next speaker who presented at the “Presidents Program” should have run for President herself, and I don’t mean of ACOG, Dr. Joycelyn Elders. I have heard her speak before, but this was one of her finest moments. She started with the accurate observation that our country does NOT deliver health care; it delivers "sick care.” There are more than 47,000,000 people in the U.S. who have NO health insurance and must rely on emergency services for even their most basic health care-related needs at an extraordinary financial drain and compromise to the efficiency of those services and the continuity of care provided.

She focused on the fact that we do not educate our children well on the importance of health, nutrition and exercise, family and responsibility. We deny our sexuality as humans, and we have leaders who naively believe that “just saying no” is the answer to all our problems. “There would be no abortions if there were no unwanted, or unplanned, pregnancies,” she said and pointed to fact that our leaders have taken the holier than though approach of putting their heads in the sand rather than to face the realities of earlier and earlier puberty in children, particularly Black children, when these children "have the hormonal imperative to reproduce" and can be readily influenced by others, not many years older, and before they can make good decisions, or even have an understanding of their sexuality and its consequences.

She supported the belief many of us have espoused for years that these are issues that need to be sensibly addressed in the schools starting at a very early age – kindergarten – because many of the kids that need it the most, don’t have the family structure to insure that they will ever be addressed at home, and those that do, may not have parents (or other caretakers) who are very good at doing it themselves for the most part due to their own lack of education and understanding. (Recently, I saw an eleven year old who was 29 ½ weeks pregnant when she arrived for her first prenatal visit. The patient had no clue what was going on, but her mother was “so excited we are going to have a girl” and all I could think about was finding the guy (probably many years older) who had gotten her pregnant and taking him off the streets).

Dr. Elders pointed to the inequity in health care services, not just among the poor and “people of color”, but in the general care and resources available to women and children. “We have the finest doctors in the world and the most advanced technology, but rank well down the list of industrialized nations” in terms of medical complications related to obesity, preterm labor, perinatal mortality, nutrition, and resources and programs to promote the health and well-being of individuals and families. Our politicians talk about, and build their careers, on rhetoric regarding the importance of these things, but do not “walk the walk.” In her own way, Dr. Elders so poignantly illustrated the same points recently hammered home by Lee Iacocca…we don’t have good leaders, we have lost our focus as a nation. We spend two billion dollars a DAY in Iraq and we can’t provide $275,000,000 a YEAR for inexpensive, cost-effective contraceptive programs. “JUST SAY NO” isn’t the answer we should be giving our children; it is the response we should be giving to the politicians on both the state and national levels when they cut programs for those least able to fight for themselves. The tears Dr. Elders gave me were based on her passion and the truth and honesty of her words and vision. She got a standing ovation.

The last speaker, Dr. Dale Hull, also provided inspiration (and wet eyes) by his personal experiences as a patient. Dr. Hull had a well-established OB/GYN practice in Utah when he was paralyzed from the neck down with a spinal cord injury suffered on the trampoline in his back yard. “True adversity is never what we planned or expected, but how we respond to that adversity makes us the people we can become.” He described his years of experience as a patient, the grief and anger, the loss of independence, the dedication of his health care providers, the support of his family and friends, his wife’s undying optimism that his body would heal, and his “miraculous” partial recovery in steps coincident with organized prayer. He emphasized the importance as physicians in providing to our patients not only our professional skills, but in keeping the door of hope open, and the power of offering “nonmedically-related touch” as an affirmation of the patient as a person. Although his recovery has gone well beyond what any of his providers ever expected (he was able to ‘carry the torch’ for a segment of the Winter Olympics in Utah) he has come to accept his limitations and no longer asks “Why or how this could happen to me?” (But he did get rid of the trampoline he had in his back yard!)

On a lighter note, I found a great place to eat tonight, if you are ever on Coronado Island across the bay from San Diego. Not far from the Hotel del Coronada on Orange Drive is the Bistro d’Asia. I started with the “Thai cucumber salad” and that was very tasty and refreshing. But, for my entrée, I got one of tonight’s ‘specials’, the “Dirty Vegas Roll,” a sushi dish made up of soft shell crab, spicy tuna, cucumber, and avocado, topped with crawfish salad, spicy aioli, and green onions, and it was ABSOLUTELY DELICIOUS…and very nice with the Chardonnay I ordered. Bon appetit et a demain!....

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ACOG Annual Meeting - San Diego - Why Do Men Have Nipples?

I am going to take some liberties here, so forgive me (or FIRE me). I know that the title of these web sites has been changed (for the better, because at least someone signing on can now easily find the sites!) to “Health Talk” but Healthline asked that I provide a “BLOG” and to me that’s what this still is! Anyway, if any of you read my post yesterday, you know I am attending the 55th Annual Meeting of the American College of Obstetricians and Gynecologists (ACOG) being held this week in San Diego. Today was a feast for the mind, senses, and emotions (and palate). For all those reasons, the meeting is already well worth having attended.

The first thing that piqued my imagination today was the ACOG logo. I had never looked at it closely, but first thing this morning I had that opportunity as it was flashed up on 6 very large screens at the start of the opening ceremonies and the “President’s Program,” comprised of keynote speakers to kick off the scientific sessions. What I learned was that ACOG was founded the year I was born, in 1951. Well, so what? Being one of those people who truly believes that things really don’t happen by chance, that struck me as bearing some (unexplained) significance at a higher level as to the ‘bass ackwards’ way I ended up in my chosen profession to begin with (read one or two of my earliest posts on this site if you don’t believe me!). ACOG and I are growing old at the same rate, both in our 56th years! Fortunately, I am sure the society will long outlive me.

Although I was a bit distracted by that irrelevant trivia, I did not miss the fact that the keynote speakers were outstanding. In fact all three brought tears to my eyes (each for very different reasons) and renewed my inspiration and enthusiasm for the work we were placed here to do. The first was Dr. David Barash, Professor of Psychology at the University of Washington. Dr. Barash discussed “Womanly Mysteries: Evolutionary Enigmas of the Female Sex.” My tears during his talk were for the laughter he brought to my heart. He had a wonderful Power Point presentation that never made it to the meeting because his pet cockatoo ate his flash drive as he was leaving home and he didn’t realize the damage that had been done until shortly before the meeting. It’s a good thing he’s written about 20 books on this and similar topics and could ad lib (or ‘stand up’) his way through the allotted 30 minutes.

He made the very important point that “scientific advances are not dead; in fact they aren’t even sick.” To illustrate this point, he raised several questions (“unknowns”) that have not yet been answered regarding women. To put things in perspective regarding Dr. Barash, he is a hardcore Darwinist (that is not said disparagingly, but in agreement) who believes that there is usually (although not always, so "Why do men have nipples?") some “selective advantage” to the things we do and are as humans (in the broader sense) or they would not have been incorporated into our genetic makeup. He simply asked questions that have not been answered (and won’t be here, but they will give you something to think about!): Why do women have “concealed ovulation” (i.e., neither they, nor their partners know (or at least, are aware) of when they are most fertile), unlike most other species? Why do women have prominent breasts, even when they aren’t lactating, unlike most other species? Why do women go through menopause, unlike most other species? Why do women experience orgasm during sex when they really don’t need to in order to conceive?

Anyway, ponder those questions, and if you come up with some goods answers, let me know. Nothing is ‘too far out’ when it comes down to it! I will finish this discussion with another post tomorrow…

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ACOG Annual Meeting - San Diego

Hey guys. On the road again. Decided to go to the American College of Obstetricians and Gynecologists (ACOG) Annual Meeting in San Diego starting this weekend. Since my specialty area is in Maternal-Fetal Medicine, I don’t get to the ACOG Meeting much anymore. The usual hot topics for discussion, menopause, osteoporosis, and contraception (all very important) aren’t overly relevant in my area and besides the first and last of those put me out of business, although I don’t see that happening anytime soon. (Don’t take care of too many perimenopausal pregnant women much anymore since I left Minneapolis about 5 years ago, although I did have a consult with a 53 year old woman a few months back who is thinking of spending the BIG BUCKS to get pregnant but that post is for another day!).

Anyway, I just couldn’t pass up the opportunity to spend a few days in San Diego this year. It has to be one of my favorite cities. Between the weather and the ocean and the people and the weather and the ocean....guess you get the picture. I am a 'back to the sea' sort of person and this is as close to an ideal place to live as I have ever been. I was at first disappointed by my hotel location. Being a little late to get in my application for the meeting, I was apparently placed at “the only convention hotel that still had rooms available,” the Hotel del Coronado. When I realized this (after we had already landed in San Diego this afternoon), having ignored the itinerary my secretary had handed me on Friday, my first thought was that I was going to miss all the downtown convention-related activities (the meeting is at the San Diego Convention Center and most attendees are staying at hotels in proximity to the convention venue). However, since the phamaceutical companies have been asked to reign in their spending so as not to unduly influence the weak of body, mind, and spirit, the obscene parties of past years have become fewer and more far between.

The Hotel del Coronado is on an island across the bay from the downtown area and is a wonderful Victorian style hotel that was first built in the late 1880’s. It has been host to the likes of Mary Pickford, Tallulah Bankhead, Charlie Chaplin, Greta Garbo,Mae West and of course Marilyn Monroe and their images can be found in various locations around the hotel. In fact, as I was walking to my room I spent a few moments worshipping at the gnarled century old tree that served as a backdrop for Some Like it Hot. And, you know what, after spending the afternoon waiting for my room to be ready, walking the property and the beach, watching the rolling waves, and basking in the sun and the steady ocean breeze, I had to admit that I would MUCH rather be here for my home base than downtown (in fact I would much rather be here than even take the shuttle to the meeting tomorrow, but I will try to behave myself).

Actually, I decided to come to the meeting to hear the ‘latest’ on several topics that are of interest to me, namely, recurrent pregnancy loss, cesarean section (elective and in relation to prevention of pelvic floor injury), and cervical cerclage. I have my own very strong opinions on those topics and like to know what the reputed ‘thought leaders’ in these areas currently have churning through their minds. So, I will try to be a good little ‘cub reporter’ and promise to update you on anything new and newsworthy in not only the OB, but the GYN arenas as well. There are a couple of other posts from last week I didn’t finish up that I will also try to include over the next few days if I can keep a clear head (Tiajuana is not very far away). Anyway, with the time difference between here and the east coast, I am on EST and my body thinks it's 3:00 AM, so I will quit babbling for now...

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Chorionic Villus Sampling

In the last several posts, I have discussed amniocentesis as a means of fetal diagnosis for chromosomal or genetic problems. Amniocentesis is considered to be an ‘invasive diagnostic procedure.’ We actually have to stick a needle through the fetal membranes (chorion and amnion) and into the sac surrounding the baby to obtain the fluid and cells we need to perform the diagnostic studies. Another common ‘invasive’ procedure we perform is chorionic villus sampling, or CVS. This procedure can best be thought of as a placental biopsy, sampling fetal placental tissues that lie outside the amniotic cavity. It is usually performed during the latter part of the first trimester (10-13 weeks) for reasons I will discuss later on, but actually is a procedure that can be done anytime, preferably, after 10 weeks, when technically feasible, and may be the procedure of choice when fetal chromosomal or genetic studies are indicated and there is little or no fluid surrounding the baby.

Like amniocentesis, we perform CVS under direct ultrasound visualization or ‘guidance.’ The procedure can be done transcervically or transabdominally and the route that is selected is determined by the position of the cervix and uterus and, most importantly, the placental location. When conditions are favorable for CVS to be done transcervically, the perineum, vagina, and cervix are first ‘prepped’ with an antiseptic solution such as povidone-iodine. The cervix is then grasped with an instrument such as a tenaculum that, with gentle traction, can be used to straighten the cervical canal, aligning the cervical canal and the uterine cavity. A catheter containing a semi-rigid stylet is then placed through the cervix to just inside the junction of the cervix and uterus. Then, using ultrasound to follow the path of the catheter tip, it is advanced until positioned beneath the placenta. The stylet is then removed, a syringe is attached to the catheter, and the catheter slowly withdrawn as negative pressure is applied with the syringe. Placental villi can be readily identified as feathery tissue in the tissue culture fluid. In the laboratory, the fetal chromosomal studies can be done by both direct preparations and tissue culture with results available within 3-4 days and 6-10 days, respectively. More cells are usually obtained by CVS than amniocentesis and the cells are usually more metabolically active, allowing a more rapid turn-around time for both chromosomal and biochemical analyses.

If the placenta is not in an accessible location for a transcervical CVS, the transabdominal route may be considered. In many ways, when the placental location lends itself to this approach, it is and often less uncomfortable procedure for the patient. This is also done under aseptic conditions and direct ultrasound guidance. Usually a 19 or 20 gauge spinal needle is used and, because of the large caliber needle, local anesthesia is generally injected at the needle insertion site. Once the needle is positioned under the placenta, a syringe is used to aspirate a sample of villi just as in the transcervical approach.

Although CVS can be done earlier in the pregnancy than amniocentesis, thereby providing results sooner, it is not without risks. Based on early studies, we have generally quoted patients an ‘excess loss rate (= background loss rate minus the procedure-related rate)’ related to CVS of about 1%, or twice the oft-quoted 1 in 200 risk of an amniocentesis later in pregnancy, a number also based on earlier studies. However, as is now the case with amniocentesis, more recent studies have shown that the risk of CVS has decreased with time and, especially, with the experience of the operators. Caughey and colleagues (Obstet Gynecol 2006;108:612-16) recently published a review of 20 years’ experience (1983-2003) with CVS (9,886 procedures) and amniocentesis (30,893 procedures) at a single institution. They found that while the risk of CVS was 4-fold that of amniocentesis over the entire time period, in the recent years between 1998 and 2003, the risks of the two procedures were equivalent and estimated to be about 1 in 370. The results from the FASTER trial, cited previously in our discussion of amniocentesis, also suggest the risk of CVS is only about 1 in 360, but when compared to that study’s results for amniocentesis (risk of 1 in 1600), CVS is still 4-fold riskier for losing a baby as a consequence of the procedure.

Immediate complications of CVS such as bleeding, rupture of membranes, and introduction of infection are surprisingly rare. However, as with early amniocentesis, other consequences of CVS were found during our early experience with the procedure. In 1991, Firth and colleagues reported 5 cases of limb reduction abnormalities among 289 CVS pregnancies (Lancet 1991;337:762-3), 4 of which were associated with ‘oromandibular hypogenesis (basically poor development of the lower face).’ Since the background risk of this complex of abnormalities is approximately only 1 in 175,000 live births, these findings following CVS were considered to be quite significant. Interestingly, all of these abnormalities occurred after transabdominal CVS procedures performed between gestational ages of 55 and 66 days. To make a long story short, the general consensus today is that there is not a significant risk of limb-reduction defects when CVS is performed between 10-13 weeks, but that the risk may be as high as 1-2% if done prior to this time, particularly when done in the 6 to 9 week time period (Jenkins and Wapner. Semin Perinatol 1999;23:403-13).

The only other issue that we typically discuss with women before they undergo CVS relates to the accuracy of the diagnosis. Vejerslev and Mikkelsen reported a 1% frequency of chromosomal mosaicism in CVS specimens (Prenat Diagn 1989;9:575-88). Chromosomal mosaicism indicates two (or more) populations of chromosomally divergent (different) cells, generally, those that are chromosomally normal and those that are not. A baby can have ‘generalized chromosomal mosaicism,’ thought to arise from a mutational event that occurs during the early divisions of the fertilized egg, and have all (or most) body tissues affected. While generalized mosaicism is a relatively rare event, it appears that similar mutations, occurring in the cells that are destined only to become the placental tissues, is not infrequent at all and when this occurs it is defined as “confined placental mosaicism (CPM).”

When mosaicism is found in a CVS specimen, it is recommended that another invasive diagnostic study, either amniocentesis or percutaneous umbilical blood sampling (yet, another post) be performed to rule out generalized fetal mosaicism. However, even if it appears that this is ruled out (there is still a small chance the baby could have a more limited distribution of mosaicism with fewer tissues involved), the finding of CPM still may indicate a pregnancy ‘at risk’ for complications related to placental ‘insufficiency’, including fetal loss, intrauterine growth restriction, and pregnancy-induced hypertensive disorders. Life is never as simple as it seems, is it?!?

Labels: amniocentesis, ChorionicVillusSampling, CVS

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Early Amniocentesis

I was discussing the content of my recent posts (April 17, 2007; April 28, 2007) about amniocentesis with one of my patients today. She was trying to decide between the options for aneuploidy screening and actual fetal chromosomal diagnosis, and the question arose regarding the current status of ‘early amniocentesis’ as an alternative to chorionic villus sampling (which we will be discussing herein sometime over the next couple of days). At the time of today’s visit she was about 12 weeks and was being seen because she will be 43 years old when she is due to deliver. At her age, the risk of delivering a baby with a chromosomal abnormality is about 1 in 40 for trisomy 21 (Down syndrome) and 1 in 31 for all chromosomal abnormalities. The chance of the baby being chromosomally abnormal in first trimester is even higher, 1 in 24 and 1 in 13, respectively. At the outset of our discussion, she was “pretty sure I want a diagnostic study done,” but also didn’t “want to place this pregnancy at any greater risk than necessary” by an invasive procedure since it was her “partner’s first child and I am not getting any younger.”

Most ‘genetic amniocentesis’ procedures are done at 15-18 weeks gestation. The relatively low risks at this point in the pregnancy have been well-documented as discussed in my previous posts. Different folks have different criteria for what they consider to be an ‘early amniocentesis’, I have always defined it to be any amniocentesis done prior to 14 weeks (while the pregnancy is still in the first trimester). We first started doing these about 20-odd years ago at a time when ultrasound technology had improved to the point that we could perform the amniocentesis under ‘direct, real-time, ultrasound guidance.’ Our naïve assumption at the time was that since the procedure seemed to be relatively safe in midtrimester, now that we could see better, it should be just as safe earlier in pregnancy.

Early amniocentesis turned out not only to be technically more difficult than expected, but also less reliable in terms of getting a final fetal chromosome result, and riskier to the pregnancy. I know one of the problems I frequently encountered was difficulty in penetrating the membranes surrounding the baby. The ‘bag of waters’ is actually composed of two layers of membranes, the amnion (closest to the baby) and the chorion. During the first part of the pregnancy, the amnion and the chorion are separated and may not fuse into one sac until the end of the first trimester, and even then, the ‘fusion’ can be weak until later in midtrimester (and sometimes remains that way if a baby has a chromosomal abnormality such as trisomy 21). It was not at all unusual during an attempt at early amniocentesis to see ‘tenting’ of the membranes (separation from each other or from the wall of the uterus) as we tried to push the needle into the space around the baby. When chorionic villus sampling (CVS) came along, providers gravitated to offering that in first trimester and amniocentesis at 15+ weeks rather than performing early amniocenteses routinely.

The only study I am aware of that has actually systematically looked at early amniocentesis was done in Canada (Canadian Early and Mid-Trimester Amniocentesis Trial (CEMAT) Group) published in 1998 (Lancet 1998;351:242-47). In this trial, 4,374 women were randomized to either early amniocentesis (between 11 and 12 6/7 weeks) or midtrimester amniocentesis (between 15 and 16 6/7 weeks). This and subsequent reports from the trial demonstrated that compared to midtrimester amniocentesis, early amniocentesis was associated with a 4-fold risk of a technically difficult (twice the risk of requiring multiple needle insertions) or unsuccessful procedure (1.6% vs. 0.4%), a 10-fold risk of chromosome culture failure (2.4% vs. 0.25%), a higher rate of fluid leakage following the procedure (3.5% vs. 1.7%), a greater risk for pregnancy losses (7.6% vs. 5.9%), and a significantly higher risk (1.3% vs. 0.1%) of having a baby with talipes equinovarus (club foot). Unfortunately, this study did not provide data for amniocenteses done between 13-14 6/7 weeks (when I did most of my ‘early amniocenteses’), but it is doubtful at this point, in view of the results of the CEMAT trial, that this study ever will be done. Today, when a patient requests an earlier diagnosis, but is reluctant to undergo CVS, I will still offer an ‘early amniocentesis’ but counsel them regarding the increased risks and request that they delay this until 14 weeks.

Anyway, after a nice discussion, my patient today decided she would go with ‘combined first trimester screening’ for aneuploidy and probably wait to have an amniocentesis done until 15-16 weeks, “regardless of whether or not the ‘screening’ test is reassuring.” For now, that is the right decision for her…As I have learned in the past, however, with further information, she might still opt for another approach after she gets back today’s final results! At least she now knows what options are available to her.

Labels: amniocentesis

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Grand Rounds 3.32 - Thanks to MyThreeShrinks

Thanks to MyThreeShrinks at Shrink Rap for including a link to my post "Second Verse Different from the First" in this week's Grand Rounds 3.32. This contribution addresses the care of an OB patient who had a tragic pregnancy outcome, followed by her second pregnancy with a good outcome that helped bring closure to the first experience for all of us - just one of the rewards of this business if you stay in it long enough! By the way, check out the 'pod cast' they have included with the links. I wish I knew enough about MP3 to have included my own musical contribution!

Labels: GrandRounds, MyThreeShrinks

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