Uterine Aging Cuts Live Birth Rates to 31.7% in Donor-Egg Recipients Aged 49+

Researchers at IVIRMA Roma grouped 1,774 recipients into four age bands and tracked clinical pregnancy, live birth, and miscarriage after adjusting for embryo quality, paternal age, and endometrial thickness. The proportion of trilaminar endometrial patterns declined from 94.7% to 81.0% with advancing age, indicating reduced receptivity independent of oocyte source. This observational design isolates uterine factors better than prior mixed-age cohorts but cannot exclude unmeasured vascular or immune confounders.

Rising mean maternal age in high-income countries has driven greater reliance on donor oocytes, yet cumulative live birth rates still dropped from 80.0% to 62.5% after age 49. Earlier registry studies in The Lancet and Human Reproduction noted similar age gradients but lacked uniform blastocyst-stage transfers and detailed endometrial morphology data, leaving the uterine contribution underestimated.

Future work must test whether targeted endometrial priming or vascular imaging can narrow the gap; randomized trials comparing standard versus age-adjusted protocols in women over 49 are required to move from association to intervention.