LAUSR

Objective: To analyze prognosis-related risk factors of first trimester cystic hygroma (CH) fetuses in which nuchal translucency (NT) was found to be thickened. Methods: Tolly 216 singleton pregnancies in which fetal NT≥3.0 mm at the 11~13+6 weeks scan accepted invasive prenatal diagnosis in Beijing Gynecology and Obstetrics Hospital, Capital Medical University, from January 2014 to December 2015 were collected. A total of 164 (75.9%, 164/216) single fetuses with complete data were included, they were classified into two groups, namely 'CH' and 'increased NT' which without CH. And 40 pregnancies (24.4%, 40/164) presented with CH group, 124 pregnancies (75.6%, 124/164) were with increased NT group. The chromosome karyotype abnormality, major organ structure malformation and adverse outcome were compared between the two groups. Logistic regression analysis was used to investigate the effect of increased NT thickness, the presence of septa in CH on abnormal karyotype, major congenital anomaly and adverse outcome. Results: (1) The incidence of fetal abnormal karyotype [55.0% (22/40) vs 29.0% (36/124) ], major organ anomalies [45.0% (18/40) vs 25.8% (32/124) ], and adverse outcome [92.5% (37/40) vs 50.8% (63/124) ] were significantly different (all P<0.05) between the CH group and the increased NT group. (2) NT measurement was significantly higher in the CH group than that in the increased NT group (8.32 vs 5.06 mm, P<0.01) . (3) Logistic analysis revealed that NT thickness was the significant risk factor in the prediction of adverse outcome for CH fetuses in first trimester. The risks of chromosomal defect, major congenital anomaly and adverse outcome increased 1.171, 1.192 and 1.913-fold (all P<0.05) with 1.0 mm increased NT thickness, while the presence of septa in CH didn't increase the risks of above (all P>0.05) . Conclusions: The perinatal outcome of CH is poor. The poor outcome of CH is closely attributed to thickened NT, and the presence of septa in CH does not increase the risk of adverse outcome for CH fetuses.