More than the oocyte source, egg donors as patients: a national picture of United States egg donors.

Purpose: To characterize national oocyte donation practice patterns from the perspective of individual donors rather than of recipients.

Methods: Retrospective cohort including all donor oocyte retrievals and transfers reported to SARTCORS in 2016 and 2017 in the USA. Primary outcomes include characteristics of oocyte donors and of donor oocyte cycles. Secondary outcomes include overall pregnancy rates, elective single embryo transfer (eSET) rates, and perinatal outcomes among donor oocyte recipient transfers.

Results: During the study period, 49,193 donor oocyte retrievals were performed, of which the largest proportion were in the Western US. For all reported retrievals, there were 17,099 unique donors, each of whom underwent an average of 2.4 retrievals (range 1-22). Average donor age was 26.3 years (range 18-48). On average, 24.6 oocytes (SD 12.4) were retrieved each cycle, ranging from 0 to 102. Among 37,657 donor oocyte recipient transfers, 20,159 (53.5%) involved eSET, and 17,725 (47.1%) resulted in live birth. Miscarriage rates were 17.5%, and good perinatal outcome (GPO), defined as full-term normal birthweight delivery, was more likely among singleton (75.7%) than multiple (23.8%) pregnancies.

Conclusion: The average number of retrievals that donors underwent and oocyte yield mirrored national guidelines; however outliers, exist that may unnecessarily increase donor risk. Additionally, among resultant donor transfers, 46.5% transferred more than one embryo despite national recommendations for eSET. The significantly higher likelihood of GPO among singleton pregnancies points to the need to further increase donor recipient eSET rates.