O-198 Obstetric and neonatal outcomes after natural frozen embryo transfer; results from a follow-up study of the Antarctica-2 RCT

Abstract Study question Do obstetric and neonatal outcomes of women who conceived through home-based monitoring the ovulation in natural cycle frozen embryo transfer (NC-FET) differ compared to hospital-controlled NC-FET using a hCG trigger? Summary answer We found no differences when versus undergoing NC-FET. What is known already associated with lower risk adverse artificial FET. The how prepare endometrium for FET, has now gained even more importance taken on dimension safety into account as it should not simply be reduced basic effectiveness. design, size, duration Between April 10, 2018 13, 2022, 1464 were included Antarctica-2 RCT (n = 732 n monitoring). For this study we performed follow-up order investigate participating live births after trial. Participants/materials, setting, methods only singleton livebirths. Main gestational age, preterm birth (PTB), very (very PTB), weight, large age (LGA) small (SGA). Additional included: diabetes (GDM), hypertensive-disorders-of-pregnancy (HDP), pre-eclampsia (PE), abnormal placentation (including placenta previa accrete), hospital admission during pregnancy, congenital anomalies death. calculated ratios absolute (95% CI) per protocol analysis. results role chance Both studyarms resulted similar rates. Singleton occured 146 (19.9%) following 148 (20.2%) monitoring. mean weeks was 39.0 (SD 0.3) group 39.3 0.2) group. significant (5/146 11/148, RR 1.00, 95% CI 0.90 – 1.10) or (1/146 2/148, hospital-based Very occurred once weight 3504.0 47.7) 3532.1 48.1) LGA (20/146 18/148, SGA (12/146 12/148, Also, HDP, PE, placentation, GDM, pregnancy anomaly. One death due pulmonary hypoplasia PTB. Limitations, reasons caution GDM patient-reported confirmed by hospital-files contacting centers. Wider implications findings preferred treatment ovulatory cycles When difference outcomes. Trial registration number applicable