2ND-TRIMESTER CYSTIC HYGROMA - PROGNOSIS OF SEPTATED AND NONSEPTATED LESIONS

Objective: To compare karyotypic, ultrasonographic, and prognostic fea tures of septated cystic hygromas and nonseptated cystic hygromas in s econd-trimester fetuses. Methods: A computerized ultrasound data base was used to identify fetuses diagnosed with cystic hygromas at 14-22 w eeks' gestation. Photographs from the initial ultrasound were reviewed retrospectively for hygroma type (septated or nonseptated) and any ab normal structural findings. Fetal karyotypes were obtained from amniot ic fluid, aspiration of hygroma pouches, or fetal tissue culture. Preg nancy outcome information was obtained from hospital charts and physic ian office records. Ultrasound findings were then compared with fetal karyotype results and pregnancy outcome data. Results: From 1990 to 19 95, 61 fetuses with cystic hygromas were identified. Karyotypes were o btained in 55 fetuses, and pregnancy outcome was available for 59. Abn ormal karyotype was present in 42 of 55 fetuses (76%). The most common chromosomal abnormality in septated hygromas was the 45,X karyotype. Trisomy 21 was the most common chromosomal abnormality in nonseptated hygromas. Compared with fetuses with nonseptated cystic hygromas, thos e with septated cystic hygromas were more likely to be aneuploid (33 o f 39 [85%] versus nine of 16 [56%]; P = .03), more likely to develop h ydrops (27 of 45 [60%] versus three of 16 [19%]; P = .005), and less l ikely to be live-born (one of 44 [2%] versus four of 15 [27%]; P = .01 ). Conclusions: Fetuses with septated cystic hygromas are more likely to be aneuploid and to develop hydrops, and thus are less likely to su rvive than fetuses with nonseptated hygromas. Copyright (C) 1996 by Th e American College of Obstetricians ann Gynecologists.