The outcomes and prognostic factors of fetal hydrothorax associated with trisomy 21

Objectives To determine the characteristics, outcomes and prognostic factors of fetal hydrothorax (FHT) with trisomy 21. Methods A nationwide survey was conducted on FHT fetuses with trisomy 21 delivered after 22 weeks’ gestation between January 2007 and December 2011 at perinatal centers. Results The 91 cases of FHT with trisomy 21 included 28 (30.8%) diagnosed in utero and 63 (69.2%) diagnosed after birth. The natural remission rate was 6.6% (6/91). Thoracoamniotic shunting (TAS) was performed in 14.3% (13/91) of cases. The survival rates of the hydropic, non-hydropic and total cases were 47.0% (31/66), 84.0% (21/25) and 57.1% (52/91), respectively. The crude odds ratio (OR) for death was 8.2 (p = 0.003) for fetuses diagnosed at 26–30 weeks of gestational age (vs. ≥30 weeks), 5.9 (p = 0.003) for hydrops, 4.0 (p = 0.04) for bilateral pleural effusion, 0.68 (p = 0.42) for associated cardiovascular anomalies and 2.1 (p = 0.26) for TAS (vs. no fetal therapy). Conclusions The prognosis of FHT with trisomy 21 was not very poor, but it was still worse than that of primary FHT. Hydrops, an early gestational age at the diagnosis and bilateral effusion, but not associated anomalies, were risk factors for death. Fetal therapy showed no survival benefit for FHT with trisomy 21.