Fresh embryo transfer versus freeze-all in predicted hyper-responders with moderate ovarian response: a retrospective cohort study.

BACKGROUND

The freeze-all strategy has been increasingly adopted in in vitro fertilization (IVF) to improve endometrial receptivity and reduce the risk of ovarian hyperstimulation syndrome (OHSS). However, its benefit in women predicted to be hyper-responders who ultimately exhibit a moderate ovarian response remains unclear.

METHODS

This study retrospectively included 197 IVF cycles between January 2021 and December 2025 in women with anti-Müllerian hormone (AMH) > 3.4 ng/mL and ≤ 14 mature oocytes retrieved after hCG triggering. Patients were stratified into fresh embryo transfer (n = 129) and freeze-all (n = 68) groups. Primary outcomes were OHSS incidence, biochemical pregnancy rate, clinical pregnancy rate, miscarriage rate and live birth rate after the first embryo transfer. Multivariable logistic regression analysis was performed adjusting for potential confounders.

RESULTS

AMH levels and ovarian stimulation parameters were significantly higher in the freeze-all group. No cases of OHSS were observed in either group. Reproductive outcomes did not differ significantly between groups. Biochemical pregnancy rate was 38.5% in the freeze-all group versus 49.6% in the fresh group (p = 0.20), clinical pregnancy rate was 29.2% versus 39.1% (p = 0.24), and live birth rate was 20.0% versus 27.8% (p = 0.32), respectively. Miscarriage rates were similar (9.2% vs 10.4%, p = 1.00). Multivariable analysis confirmed that the freeze-all strategy was not significantly associated with clinical pregnancy, live birth, or miscarriage.

CONCLUSION

In women predicted to be hyper-responders but exhibiting a moderate ovarian response, no statistically significant differences in reproductive outcomes or OHSS incidence were observed between the freeze-all and fresh embryo transfer strategies. These findings suggest that fresh embryo transfer may represent a reasonable option in carefully selected patients.