Fetal pleural effusion and Down syndrome.

Fetal pleural effusion is a rare abnormality that results from accumulation of fluid in the chest cavity. It can be classified as primary fetal hydrothorax and secondary fetal hydrothorax. The underlying causes of pleural effusion are still unknown, and the current treatment strategies are mainly based on symptoms. The prognosis of fetal pleural effusion varies significantly, ranging from spontaneous resolution to perinatal death. Recent advances in prenatal diagnostic methods and treatment such as thoracoamniotic shunting have significantly improved the survival rates for patients with or without hydrops.