Women aged 49 and over experience a significantly lower chance of fertility treatment success, even when using young donor eggs, according to new research. The findings challenge the notion that donor eggs can fully reverse the effects of reproductive aging and suggest that age-related changes in the womb lining may play a crucial role.
The study, which analyzed 1,774 women undergoing IVF with donor eggs, revealed that women aged 49 and older had double the risk of miscarriage compared to those aged 35 to 40. They were also less likely to achieve pregnancy.
Lead researcher Dr. Beatrice Crestani, from an assisted reproduction medical institute in Italy, stated that reproductive aging has traditionally been viewed as an ovarian issue. "Our findings suggest the picture is more complex," Dr. Crestani said. "If you replace older eggs with younger donor ones, you 'reset' the reproductive clock."
In the study, women in their mid-to-late 30s had a 54% chance of becoming pregnant with donor eggs and IVF. This figure dropped to approximately 43% for women aged 49 or older. Live birth rates also declined from 46% to 32%, while miscarriage rates increased from 24% to 38%.
Researchers observed age-related changes in the endometrium, the womb lining where a fertilized egg implants, among the older women. While the thickness of the lining remained similar, its condition appeared to decline with age.
Despite the decreased success rates, experts emphasize that these findings should not deter older women from pursuing donor-egg treatment, as success rates remain meaningful. However, patients should be informed that donor eggs may not entirely counteract the effects of reproductive aging, particularly beyond age 49.
Future research may explore ways to predict, prevent, or improve the condition of the womb lining in older women, potentially offering new avenues for treatment.