Today I received another comment to a post I wrote awhile back on aneuploidy (chromosomal abnormality) from a reader who has a first trimester baby that was found to have a cystic hygroma. With the growing acceptance of first trimester screening for aneuploidy as a 'standard of care' in the U.S. (the rest of the world discovered this several years back!), we are identifying more and more fetal abnormalities early in pregnancy. Since this too is becoming a topic of widespread general interest, I thought it would be worthwhile to highlight three of the comments/questions that were addressed to me so that other readers can hear about real situations and have a point of reference to current thought on this important issue. With apologies to the readers who left the original comments, I have modified the comments as necessary to the best of my understanding so that other readers will more easily understand their concerns...
Sat Jun 09, 09:10:00 AM 2007, Laura said: My name is Laura and I am 24 years old. Me and my husband went for our first 12 week ultrasound scan a couple of days ago and to our shock we were told that our unborn child has a cystic hygroma, which we are told is fluid underneath the skin at the back of the babies neck (the nuchal translucency) measuring 6 mm. We are devasted at this news because we are told the outlook is not good. It is our first pregnancy and it has taken us so long to get pregnant due to my polycystic ovaries, it just makes it so much harder to deal with. We decided to have a CVS (chorionic villus sampling). They took a biopsy from the placenta which they are now going to test. We should have the rapid test results for Down syndrome, Turner syndrome, and Edwards syndrome by 13th June. We are praying that they will come back clear. They are also going to do routine chromosomal studies to look for other chromosomal abnormalities that are not detected by the rapid test. They said if all the tests are normal, and if the fluid drains away by 18-20 weeks we may have a chance. Its just so hard to understand how some fluid behind the neck could indicate these sort of problems. I am only 24 years old, and so is my husband. We are young, fit and eat a very healthy diet, it just seems so unfair. Do you have any idea of our odds. What is the percentage of babies that do get over this? Have you had any success stories that could give us some hope? Thank you for your time and we hope to hear back soon. Laura
Tues Jun 12, 09:10:00 AM 2007, Kenneth F. Trofatter, Jr., MD, PhD responded: I know this is hard, especially in a first pregnancy you have had so much trouble getting to because of your polycystic ovary syndrome. Unfortunately, finding the cystic hygroma in first trimester is associated with a very high risk for a baby that has a chromosomal abnormality, most often Down syndrome (trisomy 21 = 47,+21)), Turner syndrome (45XO,missing one sex chromosome), or Edwards syndrome (trisomy 18 = 47,+18). Sometimes cystic hygromas are associated with gene defects and not chromosomal abnormalities per se. Examples of the latter include Noonan syndrome, Roberts syndrome, polysplenia syndrome, multiple pterygium syndrome, and others. At times the baby has no chromosomal abnormality or obvious genetic condition. Under these circumstances, there is an increased risk for a major heart abnormality as an underlying cause, although we do not entirely understand why babies develop cystic hygromas under these circumstances. The prognosis for the baby depends on what problems the baby has, chromosomal, genetic, and/or associated structural. If the baby has no chromosomal abnormality and does not go into heart failure (develop hydrops fetalis), it may well survive the pregnancy. If no syndromic problems, chromosomal mosaicism, or gene defects are discovered after delivery, the baby may have a reasonable chance at doing well. Your doctors will discuss this more with you after they get your test results back. At that point (if they haven't already), they will probably refer you to a genetic counselor to get more information. Good luck to both of you and thank you for reading. By the way, it is highly unlikely that anything you have any control over caused this to happen. If you will, let me know what the tests show and how the pregnancy turns out...
Sun June 24 11:50 AM 2007, Anonymous said: Dr. Trofatter, I am 41 year old with a 14 week pregnancy. Due to AMA (advanced maternal age) I elected to have a nuchal translucency (NT) scan done and the perinatologist found a large cystic hygroma; I was told extremely large 180mm3 and the doc was not optimistic. He performed CVS that day and we just recieved news that the FISH results were normal. Because there are no genetic defects, I was told we are looking at heart abnormalities, probably severe. My husband and I are deciding whether to terminate but the normal chromosome results makes this decision difficult. I have been doing research on the web for days now and I find myself unable to take care of myself and my family. I am reading the prognosis is poor and if I wait beyond 18 weeks I cannot terminate the pregnancy in my state. My question is can or should I get repeated ultrasound hoping the hygroma goes down and how often is an ultrasound indicated for this? Will the hygroma go down all at once or little by little or how much at a time? Please help me. Thank you
Tues June 26 02:47 PM 2007, Kenneth F. Trofatter, Jr., MD, PhD responded: Large cystic hygromas have a very poor prognosis, even if the baby is chromosomally normal. Even if the FISH results are reassuring at this point, your baby could have a chromosomal abnormality that was not detected by FISH. Your doctors have counseled you that this baby could also have a major cardiac malformation or other major abnormality that impedes return of fluid and lymph to the heart, even in the absence of a chromosomal abnormality. If the baby develops a condition called hydrops fetalis, this would indicate heart failure for any reason and the prognosis is usually fatal at that point. If the baby is chromsomally normal, has no other genetic or syndromic problem, has no major heart abnormality, and resolves the cystic hygroma, it may well survive and do quite well in the long term. I would recommend another ultrasound before 18 weeks. In many cases, major heart and other abnormalities can be identified by that time and you will have the final results of the fetal chromosome studies back to guide your decision. I am so sorry. It is difficult to be in your situation. If you have not seen a specialist in Maternal-Fetal medicine, I suggest you consider that. Thank you for reading and best wishes to you and your family.
Tues Aug 21 01:55 PM 2007, Ed said: Doctor, on our 1st trimester baby scan we were told that baby had a 5mm NT (nuchal translucency). We hoped that the consultant could give us some better news on a scan a few days later, but we have the terrible news that it was not simply a wide NT, but a large cystic hygroma of 7mm, extend down the back to the lumbar region. She gave us an 85% chance of choromsome problem and cardiac anomalies even if normal. Also of possible intrauterine death. We are choosing to terminate, we can't wait in hope for a CVS or amniocentesis that MAY indicate the baby is chromosomally normal because it is more likely abnormal. But we have terrible guilt in termination too, as the baby seems ok at the moment. From what I read on the internet, there is a glimmer of hope that the babies do turn out normal. Is this just crazy hope or not?Ed
Wed Aug 22, 04:55:00 PM 2007 Kenneth F. Trofatter, Jr., MD, PhD said... Although the prognosis is poor, there is always a "glimmer of hope." With your ambivalence and guilt related to pregnancy termination, why don't you have the CVS done and wait just a couple of days. Most labs can give you an answer in as little as 72 hours if they do a "direct prep" for the more common chromosomal abnormalities found with cystic hygromas. If the baby ends up being chromosomally normal, or has a potentially viable condition such as Turner's syndrome, the "glimmer" may improve if the baby survives the first part of the pregnancy....and even if it is chromosomally normal and succumbs, you can walk away having given it the "best shot" and it sounds like that is important for you. Just a thought. Good luck to both of you.