Fetal Cystic Lymphatic Malformations: Systematic Review on Pregnancy and Neonatal Outcomes

Evaluate pregnancy and neonatal outcomes with fetal cystic lymphatic malformations (LMs), excluding those arising from the posterior neck, to facilitate patient counseling.

A systematic review was performed in accordance with PRISMA guidance. Case series and case reports published between 2000 and 2022 were included.

Sixty-five studies (96 fetuses) met the inclusion criteria. The average gestational age at diagnosis was 25.5 weeks with the commonest location being the anterior neck (28%). All patients were diagnosed with LM using two-dimensional (2D) ultrasound. Prenatal progression in LM size, presence of intralesional bleeding, or fetal hydrops occurred in 70% (41/59), 9% (5/59), and 3% (2/59), respectively. Chromosomal and structural abnormalities were reported in 4% (2/52) and 2% (2/96), respectively. Overall livebirth rate was 94% (79/84); 12/96 resulted in termination and 5/84 in in utero demise. The average gestational age of delivery was 37.7 weeks. Exactly 19% (15/79) had a vaginal birth, of which shoulder dystocia occurred in one infant. Ex utero intrapartum treatment (EXIT) procedure was performed in 13% (10/79). Postnatal treatment commonly involved surgical excision 38% (30/79), sclerotherapy in 21.5% (17/79), or combination of both in 11.4% (9/79). Of those with reported follow-up, 4 died within 1 year, 1 developed heart failure at 2 years of life, and the remaining 44 had normal developmental outcomes.

Fetal cystic LMs, excluding those in the posterior neck, are not commonly associated with chromosomal, or additional structural abnormalities. They usually increase in size before delivery with only a minority developing complications. The good developmental outcome was reported in all survivors.