Invasive Diagnostic Testing after Reassuring First Trimester Screening for Aneuploidy?
Tuesday, January 22, 2008
Kenneth F. Trofatter, Jr., MD, PhD
Dr. T - I wrote to you a few months ago on your recurrent loss blog regarding my two 2007 1st trimester losses - I followed your advice to see a good RE (reproductive endocrinologist), we found impaired glucose tolerance, I started metformin, and I am happy to report that I am 15 1/2 weeks pregnant with what seems to be a healthy baby! So, thanks for that.
Here's my new question: I just turned 39. I had a NT done, and my risk for Downs is 1/2000 and my risk for Trisomy 18 is 1/3700 - which is reassuring. I scheduled an amnio anyway, because I am 39, and because of the possibility of the chromosomal problems with my lost pregnancies last year. Now, I am a week away from the amnio, and I am getting paranoid about the risk from the amnio of losing this baby. What I don't quite understand is how a history of previous losses impacts the risk of amnio. Does it make a difference if your previous losses were not spontaneous miscarriages, but missed ones? I was ok with my decision to have an amnio until yesterday, and now I can't get past the thought that something bad might happen. I know that my doctor doesn't care either way if I do the test or not, but I don't want to talk myself out of (or into) something if I am being overly cautious. Thanks in advance.
Liz
Tue Jan 22, 09:25:00 AM 2008
Kenneth F. Trofatter, Jr., MD, PhD said...
To Liz Jan 22: Liz, I am not going to tell you what to do. But, let me put this in perspective. The risk of the amniocentesis in experienced hands is still about twice that of your a priori risk for having a baby with Down syndrome or trisomy 18 (and probably several other chromosomal abnormalities as well) based on your first trimester screening results. In less experienced hands, the amniocentesis risk can be 10 times your first trimester screening risk! With those odds, if you did happen to be the 1 in 1000 (or 1 in 200) who lost their baby as the result of the amniocentesis, the overwhelming odds are that you will lose a completely NORMAL baby.
You are doing very well, you have been through a lot to get to this point, odds are this baby is normal, and you are 39 years old. You may not have many more opportunities if this one is lost. One option to consider, rather than jumping into the amniocentesis now, is to simply have a genetic sonogram done at 18-20 weeks. If that is normal, your a priori risk (based on the first trimester screening results, NOT your age) is reduced by at least another 50% (I generally quote folks 60-80%). So, answer me this...how does a 1 in 4,000 risk sound to you? If something really suspicious is seen at that point such as poor fetal growth, congenital heart defect, or a major marker for aneuploidy (and I am NOT talking about an echogenic intracardiac focus, or even a choroid plexus cyst alone), you could still opt for the amniocentesis with a FISH (fluorescent in situ hybridization) analysis for the more common types of chromosomal abnormalities. This can give you highly reliable results within 72 hours. Using first trimester screening, coupled with this approach, we have not missed a chromosmal abnormality in more than three years, nor lost a baby from an amniocentesis. By the way, CONGRATULATIONS! Again, best wishes to you and please let us know how you do with the pregnancy!
Dr T
Tue Jan 22, 05:27:00 PM 2008
Labels: amniocentesis, aneuploidy screening in first trimester
30 Comments:
At Fri Jan 25, 10:21:00 AM 2008,
Anonymous said…
Just read the previous msg with regards to previous lost pregnancies and age. My situation is similar in that I am 42 with 3 lost pregnancies in the last 10 years. We were not really trying to concieve except for the 1st pregnancy in 1997 which resulted in about 18 hrs of labor in an ER in my 3rd month. Anyway, Surprise to us we became pregnant last Sept 2007. My concern is that this is my last chance so how ever the baby turns out having an amniocentesis or any other genetic testing is irrelevant. Now at 19 weeks we had a 2nd ultrasound and my baby was found to have a Choroid Plexas Cyst. ONE at aprx 11x7 cm The doctor told my husband & I that it is relatively a small cyst and located in the skull/brain area that is where fluid usually resides but this fluid developed tissue around it forming a cyst. She said that if the next ultrasound in 2 months shows any other genetic markers (as no other marker were found at this time) then she would insist on full genetic testing ie amniocentesis, ect. I don't know much about that sort of testing as I have never gone through it. But how can she insist on it??? It's my baby. If I want to know in advance then that would seem to be my decision. The baby will come out either healthy or not and my husband will love & take care of him (it's a boy by the way) the best we can afford to. So who is she to say that she will insist?? All she is doing by running those extremely $$$ expensive tests is to take money out of our pockets that we will need for our new baby. Unfortunately like many Americans we have very lousy insurance. It was great when we lived in CALIF and even in AZ But here in Nebraska where insurance companies don't care to compete the insurance plans just are lousy-unless one works for the railroad or the hospital. *** JUST wanted to know your thoughts on this matter and I don't know much about Choroid Plexas Cyst. THX frm a Housewife in Scottsbluff, NE
At Fri Jan 25, 11:50:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Anonymous Jan 25: Your doctor cannot INSIST that you do that and you always have the right to find another one if that's the way she/he deals with sensitive situations like this. I have said this before and I will say it again, the diagnosis of 'choroid plexus cysts' and labeling these as an "ABNORMALITY" is one of the greatest disservices ever done to obstetrical patients. I have known women who have terminated perfectly healthy babies (without even having an amniocentesis done!) simply because they were told the baby had CPCs and could be at higher risk for a chromosomal abnormality. Personally, I consider 99%+ choroid plexus cysts to be a NORMAL DEVELOPMENTAL VARIANT. Early studies did show that babies with trismoy 18 had a high rate of choroid plexus cysts, but the opposite is NOT TRUE - in other words, MOST BABIES with CPCs do NOT have chromsomal abnormalities (and most babies with trisomy 18 have LOTS of other things wrong with them that would have led to that diagnosis anyway). I counsel patients in whom we find CPCs (and frankly, I wish we didn't even have to tell them, and sometimes I don't) that in the presnce of normal fetal growth and in the absence of a MAJOR fetal abnormality or significant 'marker' for chromosomal abnormality (such as a thickened nuchal skin-fold) the overwhelmong odds are that the baby is chromosomally normal. Incidentally, most CPCs will be gone by 24-26 weeks and no one has ever shown that the common CPCs that we see are associated with ANY long-term problems for the baby by themselves. Take a deep breath, relax, and enjoy the rest of your pregnancy. Thanks for reading and let me know if I'm wrong! Dr T
At Thu Feb 07, 02:47:00 PM 2008,
Anonymous said…
I just found the site and we are debating what to do (we have gone back and forth numerous times). We got a good First Trimester screening (1:4301 for DS and 1:7861 for Trisomy 18/13) I am 36, the NT was 1.3 wiht delta NT of -.3 CRL 63.3. I am concerned about the blood test portion which was Free Beta hCG MOM: 2:59 (95%) and PAPP-A MOM: 1:97 (80%). How could our results have been so good if the blood was not great. Do you recommend amnio?
At Sat Feb 09, 11:08:00 AM 2008,
Liz said…
Dr. T - you had asked me for an update. I followed your advice, we got an ultrasound first, and we were still considering whether to do the amnio, after that looked good too. We didn't find a good spot for the needle, so we decided to put it off for 2 weeks.
Unfortunately, fate intervened in the interim and little Shannon had a cord accident at 17w5d and died. I delivered her yesterday morning. She looked absolutely perfect in every way, and we would be surprised if we find anything wrong on autopsy. We do intend to try again soon, given that I am 39 and the clock is ticking.
Thank you again for all of your guidance through my losses and the amnio questions. I hope that we get to make these decisions about an amnio again soon. I am sure that I'll be back in touch with more questions then. One last question, if you don't mind, after childbirth, when can I expect to ovulate again? Is this bleeding like the first day of my cycle?
Liz
lizsmailbox@aol.com
At Thu Feb 14, 07:13:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Feb 7: I think the overall 'composite result' was probably good because the NT was VERY good and the serum markers were BOTH on the high end. Perhaps you were just a little further along or you have a slightly larger, and healthy placenta. If the hCG had been high and the PAPP-A was low, you would be at increased risk for Down syndrome and if both were LOW, you would have been at greater risk for trisomy 18. At this point, trust the computer calculation to have given you reliable information because the composite result is GREAT. Let us know how things turn out and thanks for reading. Dr T
At Thu Feb 14, 07:16:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Liz Feb 9: I am so sorry. Most women will ovulate within 6-8 weeks following a loss in midtrimester. Remember, you will ovulate (and therefore could get pregnant again) BEFORE you have your next normal period. I will be thinking about you and thanks for sharing your story with us. Dr T
At Thu Mar 20, 08:27:00 PM 2008,
Anonymous said…
Dear Dr. Trotter:
I am a 35 yr old who is 13 weeks pregnant. This is my first pregnancy and I am seeing a high rish specialist since I had bleeding from week 4-6. Two weeks ago, I had CVS and the preliminary results (I assume FISH) results showed a healthy baby girl without any chromosomal abnormalities. A week later the genetic specialist called me and told me the final results showed mosaic turner's syndroms and that I need to have an early amniocentesis to determine if this finding is limited to the placenta only. Why did the preliminary results show a false negative? Should I rely on the fish results from amniocentesis in order to make my decision regarding termination or wait for the final amniocanetesis results? Thank you!
At Sat Mar 22, 03:23:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Mar 20: Great questions so I wrote a full post on the subject March 22, 2008. Thanks for reading, good luck with your tests and please let us know what you find out! Dr T
At Wed Jul 16, 04:42:00 PM 2008,
anonymous said…
Dear Dr T
Just found this site and took alot of encoragement from it. I an agonising over the amnio and have been for the passed 4 weeks i am now week 20 and this is my last chance to have it. My age is 42 i got pregnant very quickly and my test results were nuchal 1.3 beta fg 1.6 and pappa 2.5 overall risk 1/1250 at 12.5 weeks. I decided not to have amnio based on this and an now so anxious about the prospect of Downs I feel quite ill with the worry. My local hospital claims their amnio miscarriage rate is between 0.5 and 1.0 per cent. I am torn between no getting pregnant again given my age and driving myself ill with stress of not knowing for sure.
many thanks anonymous
At Fri Jul 18, 05:23:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous July 16: I cannot make the decision for you, but I will tell you four things: 1) You got a GREAT test result for your age; 2) The quoted risk of the amnio at your hospital is 5 to 10 times greater than the chance that this baby has Down syndrome; 3) If you lose the baby as the result of the amnio, odds are you will be losing a NORMAL baby; and 4) If you get pregnant again, the odds are about 20-25 times greater than your current risk that you will have a chromosomally abnormal baby! But, the final choice is yours and you have to live with whatever decision you make, so best wishes! Dr T
At Mon Aug 04, 07:21:00 AM 2008,
LAUREN820 said…
I had an amnio last Wednesday and since then, I am terribly anxious about the risk of miscarriage. I had no problem so far but I rest most of the day (I am so scared that I do not date to make any activity). Could you tell me when I can start relaxing about my amnio ? When do procedure-related miscarriages usually occur ?
At Mon Aug 04, 07:27:00 AM 2008,
Anonymous said…
Dr T, I had an amnio last Wednesday and since then, I am terribly anxious about the risk of miscarriage. I have had no problem so far but I am also doing nothing during the whole day (I am so scared that I do not dare to have any activity). When will I be able to relax about the risk of procedure-related miscarriage ? When do procedure-related miscarriage usually occur ?
At Thu Aug 07, 06:51:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Lauren: Start relaxing NOW! The acute risk is rupture of membranes as the direct result of the procedure. That risk is passed. The primary risk now is the small chance of infection. That can take as long as 24 weeks to be a problem, but it is fairly rare. Let us know the results and count to 10 with some slow deep breathing (at least several times a day). Best wishes! Dr T
At Fri Aug 08, 07:47:00 AM 2008,
Anonymous said…
FROM LAUREN 820 : Dr T, Thank you very much for your answer. I was just surprised that you said that the risk of infection can last up to 24 weeks. Am I right to assume that you meant 24 days ? In the meantime, yesterday, I had to do a blood test at the hospital, and they checked if they were any markers of infection. Everything was fine. Based on that and on your reply, I suppose that the only concern that I should have right now is related to the test results. I will pray that everything is ok.
At Sat Aug 09, 06:01:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
to lauren: I meant two to four weeks! My typing skills leave a lot to be desired. Thanks for letting me know! Dr T
At Sun Aug 24, 07:02:00 AM 2008,
Anonymous said…
Dear Dr. T,
I am 33 years old, with one first trimester miscarriage last year. My husband and I were thrilled when we found out we were pregnant again.
At 12W 3d I had my first trimester screening and the results came back "fine". My NT measurement was 1mm and all blood results were "right in the middle". Overall risk: Trisomy 21: 1/2000, Trisomy 18: 1/10,000. Up until now I have been very comfortable with those results and the risks attached, but recently I've become paranoid about possible birth defects. I've made myself physically sick with worry. In fact I spoke with my genetics counselor about my worries and she scheduled me in for an ultrasound/ possible amnio tomorrow.
My first question- is why is there such a disparity between my risk of Trisomy 21 and Trisomy 18?
My second question - Considering my current state of anxiety is it best to go forward with the amnio understanding that although it can not predict all birth defects it might possibly help me put aside some of this paranoia and actually enjoy the rest of my pregnancy?
My final question - I've been vomiting intermittently for the past two days (no doubt from worry). Assuming my fears are not assuaged following the amnio procedure are there any risks to membrane rupture due to vomiting?
Thanks for your help!
At Mon Aug 25, 03:32:00 PM 2008,
Anonymous said…
Dr. T,
I'm sorry I actually misquoted my first trimester screening results in my previous questions/comment (Sun Aug 24, 07:02:00 AM 2008). My NT score was 1 based on the MoM, the exact measure was 1.9. Also my screening results were 1/2300 Down Syndrome, 1:10,000 Trisomy 18.I did go to the Dr. today, but after a brief ultrasound (I don't recall him looking for any specific markers) and reviewing my first trimester screening results he said that though he would perform the procedure he really didn’t want to knowing that my risk of complications was much higher than my risk for birth defects. In the end I opted not to have the amnio, and decided to wait for the results from my AFP (they are due any day now). We also discussed the option of still having an amnio if the AFP results were less than favorable. Do you concur with his opinion? What are the accuracy rates of these screening tests? Are there ever cases when the AFP results differ from the first trimester screen?
At Tue Aug 26, 05:39:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Aug 24: With those risk results it is so unlikely that the baby has a chromosomal abnormality that no one would recommend an amnio unless you asked for it. A pregnant 16 year old does not have that low a risk based on age alone! Could your baby have a physical abnormality - sure. But, that can usually be diagnosed by an ultrasound alone (if you like have it performed by an MFM specialist) and most will NOT be diagnosed by an invasive procedure that carries a risk as 10 times the chance your baby even has Down syndrome. In your circumstances if you lost the baby as the result of the procedure, the overwhelming likelihood is that you would lose a perfectly normal baby. Do you really want to take that chance. Of course, in the end, the final choice is yours and yours alone because you must live with the decision. I do suggest you get some professional counseling to wrestle with the anxieties you are experiencing during the pregnancy. Best wishes and please let us know how things turn out. Dr T
At Wed Sep 03, 12:00:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Aug 26: I would agree with the plan to defer the amnio in vie of those results. They really are VERY good. And, yes, unfortunately, sometimes midtrimester serum markers will give a different result than the first trimester markers. So, let's just wait and see. The strength of these 'screening' test is that are very unlikely to miss a diagnosis, but they do carry false positive rates of about 5%. Good luck and let us know what you find out. Dr T
At Sat Oct 11, 08:08:00 AM 2008,
Anonymous said…
Dr. T-- I just had an amnio on yesterday. I have been feeling great but woke up with a slight temp of 99.3. I am getting a little nervous. Do you think this is ok or do I need to worry about an infection? Thanks, Gretchen
At Tue Oct 14, 01:38:00 PM 2008,
G.M. said…
I am so hoping to get an answer!! I have been reading you like a mad woman, and it seems like the best info I have found YET! Even from my OB! (I am in montreal, the OBs are not very talkative!!!)
I am 36 and will still be 36 when I deliver.
I did what they call here an "integrated pre natal screen", which is apparently "the best".
It consists in first trimester nuchal translucency (nasal bone) + blood tests, and second trimester blood tests (including inhibin-a, HCG, estriol, etc...)
My total results for trisomy 21 was 1/694 risk. They estimated my initial risk based on age only at 1/238.
I was told this was good.
At 20 weeks, I got an ultrasound. I dont know if it is considered a "genetic" ultrasound... They measured the femur and humerus, head, abdomen.... They looked at all organs and told me everything was perfect.
She is growing exactly as planned, all though her femur and humerus are a few days ahead! (which I think is good?)
Does this ultrasound lower my risk? And if so, by how much?
Should I go for a more detailed ultrasound? Here in canada, they dont offer it... I dont even know if ti is available...
They told me that if something wrong is seen on an organ, they investigate further, but that all was fine with me.
I asked them about the pinky, etc... They said all looked fine, but they did not seem to give it so much attention!
Basically, I would love to know if my risk is lowered and by how much!
Thank you so, so much!
G.M.
At Tue Oct 14, 01:42:00 PM 2008,
G.M. said…
I am so hoping to get an answer!! I have been reading you like a mad woman, and it seems like the best info I have found YET! Even from my OB! (I am in montreal, the OBs are not very talkative!!!)
I am 36 and will still be 36 when I deliver.
I did what they call here an "integrated pre natal screen", which is apparently "the best".
It consists in first trimester nuchal translucency (nasal bone) + blood tests, and second trimester blood tests (including inhibin-a, HCG, estriol, etc...)
My total results for trisomy 21 was 1/694 risk. They estimated my initial risk based on age only at 1/238.
I was told this was good.
At 20 weeks, I got an ultrasound. I dont know if it is considered a "genetic" ultrasound... They measured the femur and humerus, head, abdomen.... They looked at all organs and told me everything was perfect.
She is growing exactly as planned, all though her femur and humerus are a few days ahead! (which I think is good?)
Does this ultrasound lower my risk? And if so, by how much?
Should I go for a more detailed ultrasound? Here in canada, they dont offer it... I dont even know if ti is available...
They told me that if something wrong is seen on an organ, they investigate further, but that all was fine with me.
I asked them about the pinky, etc... They said all looked fine, but they did not seem to give it so much attention!
Basically, I would love to know if my risk is lowered and by how much!
Thank you so, so much!
G.M.
At Fri Oct 17, 11:24:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To Gretchen: That would be a little soon for an infection from an amniocentesis, but you should really call your doctor and express your concerns. Best wishes for the rest of the pregnancy! Things will probably be fine. Dr T
At Fri Oct 17, 11:26:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To GM: A 'normal' targeted ultrasound at 18-20 weeks should reduce your a priori risks based on the integrated screen by AT LEAST 50%. I will often tell my patients, at least 60-80%! Best wishes for the rest of the pregnancy. Time to relax and enjoy yourself. Dr T
At Fri Oct 17, 11:45:00 AM 2008,
G.M. said…
Dead doctor, thank you so much!
I am in montreal, canada, and what si described to you as the ultrasound that I had is the most complete ultrasound offered here in montreal.
Is it what you would call a "targeted ultrasound"?
Again, it measured the head, abdomen, femur, humerus, and looked at the different organs, placenta, etc...
It lasted around 45 minutes.
If it is not "targeted", i guess it still reduces my risk but maybe a bit less?
Thanks again!
G.M.
At Tue Oct 21, 08:48:00 AM 2008,
Anonymous said…
Dr -
I am 40 years old and 9 weeks pg. Previous to this pg I lost a baby to T18 at 17 weeks. An early scan at 11 weeks identified the abnormalities.
We are debating about having the early scan with this baby.
My question is this - as a doctor, would you prefer to have the information provided in the scan so that you can modify treatment if needed? Do the scans make you more comfortable in your treatment decisions?
At Tue Oct 21, 06:06:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To GM: You are welcome. Best wishes for the rest of the pregnancy. Dr T
At Tue Oct 21, 07:17:00 PM 2008,
G.M. said…
One last question I am sorry...
I read that a "targeted ultrasound" -as you refer to- is the same thing as a "level 2 ultrasound".
I got what they call a level 2 ultrasound, which is basically an "ordinary ultrasound" that is done carefully and that measures many things like humerus,femur, head, abdomen, looks at organs like heart, brain, etc....
It took 45 to 60 minutes.
I just want to make sure that this is the ultrasound you are referring to that if normal, reduces my initial risk by 50%.
THank you so, so much.
G.M.
At Thu Oct 30, 03:59:00 PM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To anonymous Oct 21: I am not trying to be glib, but I honestly don't care! The only question is do YOU want to know these things sooner than later. Personally, I would want to know sooner, but I am not you and I do not have to live with that decision! I only "modify treatment" under these circumstances if YOU want that done because I cannot change things once conception has occurred. I wish you the best this time around and I am sorry for your previous loss. Dr T
At Fri Oct 31, 08:35:00 AM 2008,
Kenneth F. Trofatter, Jr., MD, PhD said…
To GM: It sounds like you got a 'targeted' scan and if that is so, then that should be at least the level of risk reduction. Dr T
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