Cystic hygroma and mid-trimester maternal serum screening

Objective: To investigate the relationship between maternal serum screening markers and pregnancy outcome in fetuses with cystic hygroma at 15–18 weeks of gestation. Study design: 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. Results 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. Conclusions 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.