Maternal age at transfer following autologous oocyte cryopreservation is not associated with live birth rates.

PURPOSE: Our aim was to evaluate if maternal age at transfer following autologous oocyte cryopreservation is associated with live birth rate (LBR).

METHODS

We performed a retrospective cohort study of all patients who thawed autologous oocytes and then underwent a single frozen euploid embryo transfer between 2011 and 2021 at a large urban university-affiliated fertility center. Each oocyte thaw patient was matched 2:1 to in vitro fertilization (IVF) patients who underwent single embryo transfer < 1 year after retrieval. Primary outcome was LBR. Secondary outcomes included implantation rates (IR) and spontaneous abortion rates (SABR).

RESULTS

A total of 169 oocyte thaw patients were matched to 338 IVF patients. As expected, oocyte thaw patients were older (median age 42.5 vs. 37.6 years, p < 0.001) and waited longer between retrieval and transfer than in vitro fertilization patients (median time 59 vs. 1 month, p < 0.001). In univariate analysis, implantation and LBR differed among oocyte thaw and IVF patients (p < 0.05), but SABR did not (p = 0.57). Transfer outcomes in oocyte thaw patients did not differ based on transfer age group (IR: p = 0.18; SABR: p = 0.12; LBR: p = 0.24). In a multiple logistic regression model, age at transfer was not predictive of live birth when controlling for age at retrieval, embryo morphology, and day of blastulation.

CONCLUSIONS

Maternal age at transfer after oocyte cryopreservation is not predictive of LBR; this suggests that "an aging womb" does not impair LBR after oocyte thaw and empowers patients to return for transfer when ready for childbearing.