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.