In Utero Treatment of Lymphatic Malformations: A Narrative Review of the Literature, Considerations, and Future Directions

Lymphatic malformations are rare congenital anomalies that range from small, self-limited lesions to large, rapidly expanding masses capable of causing serious perinatal complications, including hydrops fetalis, polyhydramnios, airway obstruction, and fetal demise. Although most lesions are managed expectantly or postnatally, in utero interventions have been attempted in highly select cases where lesions threaten pregnancy viability or safety of delivery. Reported approaches include the perinatal option of ex utero intrapartum therapy, intrauterine ultrasound-guided cyst aspiration for decompression, intrauterine intralesional sclerotherapy with agents such as OK-432, and more recently, maternal pharmacologic therapy targeting the mTOR pathways. This review summarizes the available literature describing prenatal management of these lesions, including procedural techniques, maternal and fetal outcomes, and emerging strategies. Together, these findings highlight the potential promise and the caution necessary in translating postnatal therapeutic advances for lymphatic malformations to the prenatal setting.