The prognostic factors and outcomes of primary fetal hydrothorax with the effects of fetal intervention.

Objective: This study aims to determine the prognostic factors and outcomes of primary fetal hydrothorax (FHT) and investigate the effects of fetal therapy.

Methods: A nationwide survey was conducted on fetuses with primary FHT delivered after 22 weeks of gestation between January 2007 and December 2011 at perinatal centers.

Results: Among the 287 cases of primary FHT, the survival rates for those with and without hydrops were 58.0% (113/195) and 97.8% (90/92), respectively. The survival rates in the no-therapy, thoracocentesis, and thoracoamniotic shunting (TAS) groups in the hydropic cases and the non-hydropic cases were 59.7% (40/67), 51.5% (35/68), and 63.3% (38/60) and 98.1% (53/54), 96.3% (26/27), and 100% (11/11), respectively. The crude relative risk for death was 2.1 (p = 0.005) for fetuses diagnosed at 26 to 30 weeks of gestational age (vs ≥30 weeks), 2.3 (p = 0.001) for both skin edema and ascites, and 3.1 (p = 0.02) for bilateral pleural effusion. TAS was associated with a significant risk reduction for death in hydropic cases [adjusted relative risk 0.61, p = 0.01 (vs no fetal therapy)].

Conclusions: Hydrops and an early gestational age at diagnosis (<30 weeks of gestation), skin edema with ascites, and bilateral effusion predicted a poor prognosis in primary FHT cases. TAS was associated with a higher survival rate. © 2016 John Wiley & Sons, Ltd.