Primary fetal pleural effusion: Characteristics, outcomes, and the role of intervention.

BACKGROUND: We aimed to present the natural history and outcomes of fetal primary pleural effusions (PPE).

METHODS: Fetuses with prenatal diagnosis of PPE delivered between January 2011 and June 2018 were included. Fetal PPE were separated into groups: resolved, stable, or progressive. Progressive PPE was diagnosed, using fetal echocardiography, by the new onset of fetal hydrops or impaired cardiac function. Data were reported as median [range] and n (%).

RESULTS: Among 189 fetuses with antenatal diagnosis of pleural effusion, 30 had a PPE. A total of 26.7% (n = 8), 26.7% (n = 8), and 40.0% (n = 12) were classified as resolved, stable, and progressive, respectively; two were lost to follow-up. In 14 cases (50%), there were bilateral pleural effusions. Of the 12 cases in the progressive group, four (33.3%) had amnioreduction, six (50.0%) had thoracentesis, and eight (66.7%) had shunt placement performed. There were two fetal deaths, both in the progressive group, one of which received amnioreduction and the other underwent both thoracentesis and shunt placement prior to demise.

CONCLUSION: In more than half of fetuses with prenatal PPE, the effusion remained stable or spontaneously resolved, and the perinatal outcomes were generally favorable. This information will be useful in optimizing the counseling and care of these patients.