OC02.06: Fetal and neonatal brain injury following laser ablation for TTTS as detected by pre‐ and postnatal brain imaging

Abstract

Objectives: To determine the rate of fetal and neonatal brain lesions and define risk factors for such injury following laser ablation for Twin-twin transfusion syndrome (TTTS). Methods: A retrospective cohort study of 83 women with monochorionic twin pregnancies who underwent laser ablation for TTTS at a single tertiary medical centre. Immediate post-laser survivors were followed-up with fetal brain neurosonogram every 2 weeks and fetal brain MRI at 28-32 weeks of gestation; post-natal brain imaging included brain ultrasound. Cases with pre-and post-natal brain lesions were compared to those without. Results: Overall, 153 fetuses survived the immediate post-laser period and were available for brain imaging. Of these, 17 (11.11%) exhibited brain lesions on prenatal imaging studies, and 36(23.53%) demonstrated brain lesions on post-natal ultrasound. Comparison of fetuses with and without prenatal brain lesions revealed that gestational age (GA) at the time of laser ablation (23.0 weeks vs. 21.4 weeks, respectively, p = 0.0244), post-laser development of TAPS (29.41% vs. 9.56%, p = 0.035) and weight discordancy at birth (30% vs 9%, p = 0.0025) were associated with prenatal brain injury. The rate of prenatal brain injury was significantly higher when ablation was performed between 20-23 weeks compared to 16-19 weeks (17.07% vs. 2.08%, p = 0.031). Factors found to be associated with post-natal brain lesions included GA at delivery (31.0 weeks in those with lesions vs. 32.2 in those without,p = 0.0002) and post-laser TAPS (25% vs. 9.33%,p = 0.038). Conclusions: Survivors of laser ablation for TTTS are at risk for brain injury, which can be detected prenatally by ultrasound and/or MRI. Later GA at laser ablation and post-laser TAPS are associated with increased risk for prenatal brain injury. These findings highlight the importance of incorporation of neurosonogram and fetal brain MRI into routine surveillance of monochorionic twin pregnancies following laser ablation for TTTS. OC02.07 Relevant obstetric factors associated with twin pregnancies for cerebral palsy in Japan