Comparison of Pregnancy Outcomes of Previable and Periviable Rupture of Membranes After Laser Photocoagulation for Twin–Twin Transfusion Syndrome

To describe the pregnancy outcomes of patients who experienced previable and periviable prelabor rupture of membranes (PROM) after the treatment of twin–twin transfusion syndrome. METHODS: We conducted a retrospective cohort study of patients whose pregnancies were complicated by twin–twin transfusion syndrome who were treated with fetoscopic laser photocoagulation at a single fetal center and subsequently experienced PROM from April 2010 to June 2019. Outcomes were infant survival and latency from PROM to delivery. Patients were grouped by gestational age at PROM (before 26 weeks of gestation and 26 weeks or later). The group with PROM before 26 weeks of gestation was stratified by gestational age at PROM for further description of outcomes. RESULTS: Two-hundred fifty of 653 patients (38%) developed PROM, 81 before 26 weeks of gestation and 169 after 26 weeks of gestation. In the setting of PROM before 26 weeks of gestation, the rate of survival of both twins to neonatal intensive care unit (NICU) discharge was 46.3%, compared with 76.9% in the setting of PROM at 26 weeks of gestation or later (P<.001); the survival rate of at least one twin was 61.2% and 98.5%, respectively (P<.001). Fourteen, 22, and 45 patients experienced PROM at 16–19 6/7, 20–22 6/7, and 23–25 6/7 weeks of gestation, respectively. Survival of both twins and at least one twin to NICU discharge was 25.0%, 47.4%, 52.8% (for two) and 33.3%, 47.4%, and 77.8% (for at least one), respectively, among those groups. Fifty-seven of the 81 patients with PROM before 26 weeks of gestation experienced a latency longer than 48 hours. In the setting of PROM before 26 weeks of gestation, when latency lasted longer than 48 hours, overall survival was improved (69.6% vs 53.7%, respectively, P=.017). With latency longer than 48 hours and PROM at 16–19 6/7, 20–22 6/7, and 23–25 6/7 weeks of gestation, survival of both twins to NICU discharge was 60.0%, 61.5%, and 60.7%, respectively, and survival of at least one twin was 80.0%, 61.5%, and 85.7%, respectively. CONCLUSION: Earlier gestational age at PROM after laser photocoagulation is associated with longer latency but lower rates of survival. When PROM occurs before 26 weeks of gestation and latency exceeds 48 hours, rates of neonatal survival are significantly improved.