Short- and long-term outcome following thoracoamniotic shunting for fetal hydrothorax

Objectives: To assess short- and long-term outcome in a cohort of fetuses diagnosed with hydrothorax (FHT) which underwent thoracoamniotic shunting in utero, and to examine the antenatal predictors of survival and of survival with normal neurodevelopmental outcome.

Methods: This was a retrospective analysis of 132 fetuses that underwent thoracoamniotic shunting at our center between 1991 and 2014. Data were extracted from hospital obstetric and relevant neonatal intensive care and neonatal developmental follow-up databases. Outcomes included survival to discharge and survival with normal neurodevelopmental outcome beyond 18 months. Information on malformations, syndromes and genetic abnormalities were obtained from antenatal, postnatal and pediatric hospital records or by parent report. We compared pregnancy characteristics among those who survived vs non-survivors and among those with normal neurodevelopmental outcome vs those who were abnormal or died. We explored whether there was a trend in survival over the study period.

Results: The mean gestational age at diagnosis of FHT was 25.6 weeks. The fetus was hydropic at diagnosis in 61% of cases, 69% had bilateral effusions and 55% had bilateral shunts inserted. Other diagnoses were present in 24% of cases, two-thirds of which were discovered only postnatally. There were 16 intrauterine and 30 neonatal deaths, with a 65% survival rate overall. The mean gestational age at delivery of liveborns was 35.4 (range, 26.9-41.6) weeks, and 88/116 (76%) were preterm (< 37 weeks). Of 87 liveborn at the treatment center, 75% experienced some respiratory and/or cardiovascular morbidity after birth, many with a lengthy hospital stay (mean, 36 (range, 1-249) days). Overall, 84% of survivors were developmentally normal beyond 18 months and outcomes were better when pleural effusions were isolated, 92% of these cases being neurodevelopmentally normal. There was no trend in survival or neurodevelopmental outcome over time. Despite the presence of FHT and neonatal respiratory issues, most (89%) of the 55 survivors with relevant follow-up had no long-term pulmonary complications. Gestational age at delivery was the only factor independently predictive of both survival and survival with normal neurodevelopmental outcome.

Conclusions: FHT is associated with other pathologies in a quarter of cases and carries a significant risk of prematurity, mortality and neonatal morbidity. The outcome is good in survivors but is best in isolated cases. Predictors of outcome at diagnosis are poor. Future improvement in diagnostics at time of identification of FHT may help to identify those that would benefit most from thoracoamniotic shunting. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.