Intrafetal fluid effusions and pulmonary growth after pleuroamniotic shunt in fetuses with severe hydrothorax

OBJECTIVE: To assess the longitudinal intrathoracic changes after pleuroamniotic shunting in fetuses with massive unilateral or bilateral hydrothorax. METHODS: The presence of intrafetal fluid effusions, and the observed/expected lung-to-head ratio (O/E-LHR) of both lungs were weekly evaluated in a cohort of fetuses with severe hydrothorax treated pleuro-amniotic shunting (PAS) in a single reference center in Mexico. Severe fetal hydrothorax was diagnosed as an accumulation of fluid within the fetal pleural space accompanied with severe bilateral lung compression, mediastinal shift, polyhydramnios, and/or hydrops. The longitudinal changes in intrafetal fluid effusions, and pulmonary growth were analyzed by survival and multilevel analysis against weeks after fetal intervention. RESULTS: Fifty-six pregnancies with severe fetal hydrothorax were treated with PAS at a median gestational age of 30.1 (range, 20.8-36.1) weeks. After shunting, all cases were longitudinally analyzed and in whom a total of 332 scans were performed (median 6, range 2-16). A complete disappearance of hydrops and hydrothorax was observed at a median interval of 1.6 and 5.9 weeks after PAS, respectively. A progressive increase in lung growth were observed, becoming normal O/E-LHR at on average 7.0 weeks after PAS. CONCLUSION: Fetal pleuro-amniotic shunting promotes disappearance of all fetal fluid effusions, and a normalization of the pulmonary growth after fetal intervention.