Oocyte donor age has a significant impact on oocyte recipients' cumulative live-birth rate: a population-based cohort study

Objective: To study the impact of the donor's and recipient's age on the cumulative live-birth rate (CLBR) in oocyte donation cycles.

Design: A population-based retrospective cohort study.

Setting: Not applicable.

Patient(s): All women using donated oocytes (n = 1,490) in Victoria, Australia, between 2009 and 2015.

Intervention(s): None.

Main outcome measure(s): The association between the donor's and recipient's age and CLBR modeled by multivariate Cox proportional hazard regression with the covariates of male partner's age, recipient parity, and cause of infertility adjusted for, and donor age grouped as <30, 30-34, 35-37, 38-40, and ≥41 years, and recipient age as <35, 35-37, 38-40, 41-42, 43-44, and ≥45 years.

Result(s): The mean age of the oocyte donors was 33.7 years (range: 21 to 45 years) with 49% aged 35 years and over. The mean age of the oocyte recipients was 41.4 years (range: 19 to 53 years) with 25.4% aged ≥45 years. There was a statistically significant relationship between the donor's age and the CLBR. The CLBR for recipients with donors aged <30 years and 30-34 years was 44.7% and 43.3%, respectively. This decreased to 33.6% in donors aged 35-37 years, 22.6% in donors aged 38-40 years, and 5.1% in donors aged ≥41 years. Compared with recipients with donors aged <30 years, the recipients with donors aged 38-40 years had 40% less chance of achieving a live birth (adjusted hazard ratio 0.60; 95% CI, 0.43-0.86) and recipients with donors aged ≥41 years had 86% less chance of achieving a live birth (adjusted hazard ratio 0.14; 95% CI, 0.04-0.44). The multivariate analysis showed no statistically significant effect of the recipient's age on CLBR.

Conclusion(s): We have demonstrated that the age of the oocyte donor is critical to the CLBR and is independent of the recipient woman's age. Recipients using oocytes from donors aged ≥35 years had a statistically significantly lower CLBR when compared with recipients using oocytes from donors aged <35 years.