Natural history and outcome of prenatally diagnosed cystic hygroma

Objective To define the outcome in cases of cystic hygroma diagnosed from a routine obstetric population. Method This was a retrospective study of 42 cases of fetal cystic hygroma detected at 11 to 23 weeks' gestation in a routine obstetric population of 25352 pregnancies. Fetal cystic hygroma was categorized according to position, severity, presence of cardiac defects and Hydrops fetalis. Results There were 20 (47.6%) cases with aneuploidy (9 trisomies and 11 Turner's syndrome). Major congenital cardiac defects were identified in 12 (28.6%) cases. Regression of the hygroma was noted in 2/20 (10%) of the aneuploid pregnancies and 3/17 (17.6%) of the euploid pregnancies. The majority (90.0%) of the aneuploid fetuses were female. In contrast, 70.58% of the fetuses in the euploid group were male and all the surviving normal babies were also male (n = 3). Conclusion The findings of this study would support invasive prenatal diagnosis for an ultrasound finding of fetal cystic hygroma. Even in euploid pregnancies with cystic hygroma, there is a high mortality with associated abnormalities. The data also suggest a guarded pregnancy prognosis for the finding of fetal cystic hygroma, and that it is improved with spontaneous resolution, especially in male fetuses of normal karyotype. Copyright (C) 2004 John Wiley Sons, Ltd.