Cystic hygroma and mid-trimester maternal serum screening

To investigate the relationship between maternal serum screening markers and pregnancy outcome in fetuses with cystic hygroma at 15-18 weeks of gestation.

We retrospectively reviewed case-notes of 34 consecutive singleton fetuses with cystic hygroma referred at 15-18 weeks of gestation. All cases had maternal blood sampled for triple screening at the time of the ultrasound scan.

In total, 62% of fetuses with cystic hygroma had abnormal chromosome complements and 80% had a poor outcome. Six fetuses presenting normal values of human chorionic gonadotropin (0.5-2.5 MoM [multiples of the median]), serum alpha-fetoprotein (0.5-2.5 MoM) and unconjugated estriol (>0.5 MoM), normal karyotype and absence of associated structural anomalies had an uneventful outcome.

Our data demonstrated that cystic hygroma at 15-18 weeks has a strong association with chromosomal abnormalities. In euploid fetuses, maternal serum screening results may have a role in the diagnostic work-up of the pregnancy.