Recipient outcomes in an oocyte donation programme: should very young donors be excluded?

Research question: Does the oocyte donor's age affect live birth rate (LBR) in recipients? Design: Retrospective study of 3766 oocyte recipient cycles carried out between January 2009 and December 2018. Cycles were categorized into groups according to donor's age: <20 years (4.7%); 20-25 years (41.1%); =26 years (54.2%). Chi-squared test was used to evaluate differences in LBR and analysis of variance was used to test differences in embryo quality, and fertilization and embryo development rates. A generalized linear mixed model was applied to estimate the odds for each end point. Results: LBR was 40.7%. When analysed according to donors' age, significant differences were found: 33.9% for the youngest group, 39.1% for the group aged 20-25 years, and 42.5% for donors aged =26 years (P = 0.022). When adjusting for confounding factors (recipient age, number of transferred embryos and day of embryo transfer), LBR was lower in the group aged <20 years (OR 0.70; CI 95% 0.50 to 0.99) and in the group aged 20-25 years (OR 0.85; CI 95% 0.74 to 0.98) compared with the group aged =26 years. No significant differences were observed in fertilization rates (74.2%, 76.1% and 77.5%) or embryo development rates (57.0%, 61.4% and 62.0%). The number of good-quality embryos transferred was significantly lower in the group aged <20 years (1.03 +/- 0.71; 1.18 +/- 0.69; 1.19 +/- 0.67; P = 0.015). Conclusions: LBR is significantly lower when donors are younger than 25 years and, especially, when they are younger than 20 years.