Abstract
Congenital chylothorax remains a poorly understood condition, and the optimal approach to its management continues to evolve. Rapid progression of pleural effusion with mediastinal shift and/or development of hydrops fetalis are key indications for urgent fetal intervention to enable thoracic decompression and prevent fetal compromise. We report a case of isolated mild unilateral pleural effusion identified during routine midtrimester ultrasound, successfully managed through close ultrasonographic surveillance and perinatal thoracocentesis performed immediately before delivery to facilitate lung expansion and minimize cardiopulmonary compromise. Prenatal intervention in this context was associated with favorable neonatal outcomes, including improved Apgar scores, reduced ventilator dependence, and fewer complications.