Objective To determine the rate of and risk factors for fetal and neonatal brain lesions following laser ablation for twin‐to‐twin transfusion syndrome (TTTS). Methods A retrospective cohort study of 83 women with monochorionic twin pregnancies who underwent ablation for TTTS at a single tertiary hospital. Post‐laser survivors were followed‐up with fetal neurosonogram every 2 weeks and fetal brain MRI at 28–32 weeks of gestation; post‐natal brain imaging included neurosonogram. Cases with pre‐ and post‐natal brain lesions were compared to those without. Results 153 fetuses survived the immediate post‐laser period and underwent brain imaging. Of these, 17 (11.11%) exhibited brain lesions on prenatal imaging studies, and 36 (32.4%) on post‐natal ultrasound. Later gestational age (GA) at the time of ablation (23.0 vs. 21.4 weeks, p = 0.0244), post‐laser twin‐anemia‐polycythemia‐sequence (TAPS) (29.41% vs. 9.56%, p = 0.035) and birthweight discordancy (30% vs. 9%, p = 0.0025) were associated with prenatal brain lesions. Earlier GA at delivery (31.0 weeks vs. 32.2, p = 0.0002) and post‐laser TAPS (25% vs. 9.33%, p = 0.038) were associated with post‐natal brain lesions. Conclusions Survivors of ablation for TTTS are at risk for brain lesions, which can be detected prenatally. Incorporation of neurosonogram and fetal brain MRI into the routine surveillance of such pregnancies should be considered.

Objectives To determine the rate of fetal and neonatal brain lesions and define risk factors for such lesions in pregnancies complicated by Twin Anemia Polycythemia Sequence (TAPS). Methods A retrospective cohort study of monochorionic twin pregnancies which were diagnosed with TAPS in a single tertiary medical center between 2013 and 2021. Pregnancies were followed with fetal brain neurosonogram every 2 weeks and fetal brain MRI (magnetic resonance imaging) was performed when indicated at 28–32 weeks of gestation; post‐natal brain imaging included neonatal brain ultrasound. Pregnancies with pre‐ and post‐natal brain lesions were compared to those without such findings. Results Overall, 23 monochorionic diamniotic pregnancies were diagnosed with TAPS over the study period resulting in perinatal survival of 91.3% (42/46). In 6/23 (26%) pregnancies and 7/46 (15.2%) fetuses pre‐ or post‐natal brain lesions were detected, of whom five were the polycythemic twins and two were the anemic twins. Brain findings included intra‐cerebral hemorrhage and ischemic lesions and were diagnosed prenatally in 6/7 (85.7%) cases. No risk factors for severe brain lesions were identified. Conclusions TAPS may place the fetuses and neonates at increased risk for cerebral injuries. Incorporation of fetal brain imaging protocols may enhance precise prenatal diagnosis and allow for accurate parental counseling and post‐natal care.

No abstract