SIGNIFICANCE OF SEPTATIONS IN ISOLATED FETAL CYSTIC HYGROMA DETECTED IN THE 1ST TRIMESTER

Recent reports have indicated an increased risk for fetal chromosome a bnormalities, especially autosomal trisomy, in fetuses with isolated c ystic hygroma, or prominent nuchal membranes, detected by ultrasonogra phy during the first trimester. However, these reports present contrad ictory information regarding the prognostic significance of septations within the cystic hygroma. We evaluated, in blind fashion, 55 consecu tive cases of isolated fetal cystic hygroma detected at or before 13.9 weeks' gestation to determine the association between septations and fetal chromosome complement. Septations were associated (P<0.05) with an increased risk for fetal chromosome abnormalities. However, the inc idence of chromosome abnormalities was also increased (12.5 per cent) among cases not characterized by septations. Thus, we believe it prude nt to offer invasive prenatal testing to all women found to be carryin g fetuses with cystic hygroma, irrespective of the presence or absence of septations.