Assisted hatching and live births in first-cycle frozen embryo transfers

Objective To assess the effect of assisted hatching (AH) on live-birth rates in a retrospective cohort of patients undergoing first-cycle, autologous frozen embryo transfer (FET). Design Longitudinal cohort using cycles reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System between 2004 and 2013. Setting Not applicable. Patient(s) Women who underwent first-cycle, autologous FET with (n = 70,738) and without (n = 80,795) AH reported from 2004 to 2013. Intervention(s) None. Main Outcome Measure(s) Live births. Result(s) Propensity matching was used to account for confounding covariates, and a logistic regression model was constructed to identify the predictors of live-birth rates in relationship to AH. In all first-cycle FETs, there was a slight but statistically significant decrease in the live-birth rate with AH compared with no AH (34.2% vs. 35.4%). In older patients and in the years 2012–2013 AH was associated with decreased live births. Live-birth rates and the number of AH cycles performed before FET vary by the geographic location of clinics. Conclusion(s) Assisted hatching slightly decreases the live-birth rate in first-cycle, autologous FET. Its use should be carefully considered, especially in patients 38 years old and older. Prospective, clinical studies are needed to improve our knowledge of the impact of AH.