Late-onset fetal bilateral pleural effusions associated with Down syndrome

We present two cases of late-onset bilateral fetal pleural effusions associated with fetal Down syndrome.

Case 1. A 33-year-old Vietnamese woman had undergone regular sonographic examinations since 23 weeks of gestation and no abnormality had been noted. However, bilateral moderate pleural effusions were found at 33 weeks of gestation, and massive pleural effusion, ascites and polyhydramnios developed at 34 weeks of gestation. Aspiration of the pleural effusion was subsequently performed. Clinical laboratory surveys of the aspiration fluid excluded toxoplasmosis and cytomegalovirus infection. Cytogenetic analysis of cultured lymphocytes derived from pleural effusion revealed a karyotype of 47,XX,+21. The parents elected to continue the pregnancy. Intrauterine fetal demise occurred at 37 weeks of gestation, and a macerated female baby was delivered. Postnatal cytogenetic analysis of the umbilical cord confirmed the prenatal diagnosis. Case 2. A 41-year-old Pakistani woman had undergone regular sonographic examinations and no abnormality had been noted. However, isolated bilateral mild pleural effusions were noted at 27 weeks of gestation. Amniocentesis revealed a karyotype of 47,XY,+21 and simultaneous array comparative genomic hybridization analysis of uncultured amniocytes confirmed the diagnosis of Down syndrome. The pregnancy was subsequently terminated.

Fetuses with Down syndrome may present late-onset bilateral pleural effusions. Prenatal diagnosis of late-onset bilateral pleural effusions should raise the possibility of fetal Down syndrome and cytogenetic investigation is warranted.