With my first pregnancy a cystic hygroma was found at 13 weeks. I had an amniocentesis done which came back normal for all genetic and chromosomal abnormalities. We went through all other tests that were offered and at 35 weeks the cystic hygroma was gone. My daughter was born perfectly healthy and now is 17 months and even a bit advanced for her age.
I am now pregnant with baby #2. Today I went for the 1st trimester ultra screening and yet again the baby was diagnosed with a cystic hygroma of 6mm. Have you ever heard of this happening twice? I'm so nervous because I feel like we beat the odds once. Can it happen again? The doctors can't give me an explanation and are providing nothing better than the first time. I will be having the CVS test on Feb 8th and the waiting period is the hardest part. Any advice would be greatly appreciated. All the best, Kristi
As we have reviewed previously, cystic hygromas result from abnormal development of lymphatic tissue between the 6th and 9th weeks of gestation so that the normal drainage pathways either do not develop or are delayed in development. About 80% of cystic hygromas are found in the neck and appear as septated or nonseptated fluid-filled spaces along the back and sides of the neck – often in a somewhat asymmetrical fashion – and highly variable in size. If the drainage pathways eventually develop, the fluid collections will resolve and the baby may only be left with redundant skin in the neck area, classically relected in the ‘webbed neck’ seen in Turner’s syndrome (45 XO). If the drainage pathways never form, the baby may go on to develop obstruction of the internal jugular vein and eventually fetal heart failure associated with hydrops fetalis and diffuse fluid accumulation in the skin and body cavity spaces around the lungs (pleural effusions) and in the abdomen (ascites).
Most cystic hygromas are found in babies with chromosomal abnormalities – the most common being Turner’s syndrome (50%); trisomy 21 or Down syndrome (6.6%); trisomy 18 (5%); trisomy 13 (3.3%); and 47 XXY (1.6%). However, in recent years, we have also discovered that cystic hygromas may be an indirect indicator of major heart malformations and diaphragmatic hernias even in chromosomally normal children. Cystic hygromas may also be found in certain genetic conditions, such as Noonan and Roberts syndromes and in some cases of fetal alcohol syndrome. It is estimated that 15-25% of babies with cystic hygromas are actually chromosomally normal, but not all of these will do well. Indeed, if hydrops fetalis develops in a baby with a cystic hygroma, it is almost uniformally fatal.
Now to get down to Kristi’s question...”Can it happen again?” The answer is yes. It can happen by chance in subsequent pregnancies, and be caused by completely unrelated events, and there appear to be rare instances when it is the result of a familial inheritance pattern – most likely autosomal recessive. In 1990, Watson and colleagues (Prenatal Diagnosis 1990;10:37-40) described the case of a woman who had three consecutive fetuses with cystic hygromas and hydrops – two of which were confirmed to be chromosomally normal – however, none of these babies survived. Teague and colleagues (Matern Fetal Med 2000;9:366-9) reviewed the limited literauture on this subject in their discussion of another instance in which a 19 year old woman had three consecutive chromosomally normal babies that she lost with cystic hygromas and hydrops. More recently, however, and on a more upbeat note, Rotmensch and colleagues (Prenat Diagn 2004;24:260-4) described 18 families in which 18 pairs of siblings were affected by transient, nonseptated cystic hygromas detected during pregnancy. All women underwent amniocenteses and ALL babies were chromosomally normal. Furthermore, all babies had normal hearts, normal growth, no other physical abnormalities, and were reportedly developmentally normal following delivery.
So, Kristi, since you have had a baby with a cystic hygroma who has subsequently turned out ‘normal’, and you now have another baby with a cystic hygroma, my prayer for you is that this is simply the result of a familial inheritance pattern rather than a chance event (because if it is chance, then the risk of chromosomal abnormality is high). If you are fortunate enough to be one of those folks with a ‘familial pattern’ of inheritance where the outcome for the baby is good, then don’t be too hard on your doctors about not answering your questions because this is an extremely rare event! Best of wishes for the rest of the pregnancy, and let us know what happens, please! Dr T