[Oocyte donation: Impact of oocyte allocation practices on live births and remaining frozen embryos]

Oocyte donation-indicated in cases of ovarian insufficiency, genetic abnormalities or repeated in vitro fertilization failures-meets a growing demand for assisted reproduction. In 2023, about 520 children were born in France through egg donation, while by the end of 2023, around 2500 women were still awaiting access to this procedure. This practice raises the issue of surplus embryos, especially as no national registry currently monitors them.

We conducted a retrospective, multicentre, comparative cohort study between 2019 and 2022. The study assessed the impact of oocyte donation on surplus embryo production through quantitative analysis of oocyte outcomes. A predictive statistical model was developed to optimize oocyte allocation.

Data from 1234 "donor" patients were collected from 12 French centres, encompassing outcomes for 8,953 fresh oocytes and 2982 vitrified oocytes. The live birth rate was 7.0% per fresh oocyte and 5.1% per vitrified oocyte. On average, 5.7 fresh oocytes were allocated per recipient and 5.9 vitrified oocytes. In 2023, 1033 embryos from fresh oocytes (25% of total embryos) and 221 embryos from vitrified oocytes (23% of total embryos) remained in storage. We recommend allocating 4 fresh or 5 vitrified oocytes per donation, with a second donation if necessary, balancing a 50% success rate while limiting surplus embryos.

An oocyte allocation strategy based on successive moderate-sized donations appears likely to limit the production of surplus embryos compared with a single larger donation.