Expert's Perspective

Treating East Asian Women For Infertility

East Asian (including Chinese, Korean, Japanese, and Vietnamese) women have been demonstrated to have a longer duration of infertility by the time they reach consultation compared to white women which may influence their chance for success with ART (Assisted Reproductive Technology).

There is substantial evidence within the US ART population that East Asian women have poorer outcomes from fresh embryo transfers. A study utilizing the SART database drawing from 25,843 Caucasian and 1,429 Asian patients demonstrated decreased cumulative pregnancy (CPR) and live birth rates (LBR) among Asian women undergoing IVF compared to Caucasian women (CPR 33.3% among Asian as compared to 41.3% among Caucasians and 26.9% LBR for Asian and 34.9% for Caucasians). Generally speaking, East Asian women had 1/3 lower likelihood of pregnancy from a fresh embryo transfer compared to Caucasian women.

East Asian women appear to metabolize estrogen differently than Caucasian women. That matters because this drives higher estrogen levels during IVF stimulation, which during a fresh transfer (takes place shortly after the eggs are retrieved), may influence whether the woman’s endometrium is receptive to having the embryo implant.

Relatedly, at UCSF, we’ve also shown a lower pregnancy rate was seen in East Asian women as compared to Caucasians following stimulated intrauterine insemination (IUI) despite similar baseline characteristics between the two groups.

Interestingly, we do not see differences in success when the East Asian woman uses donated eggs during a fresh transfer or during frozen embryo transfers. These observations would lead us to believe that the reduced pregnancy success in East Asian women may be due to greater negative effects on the receptivity of the uterine environment during ovarian stimulation compared to Caucasian women. Further evidence demonstrating similar rates of embryo aneuploidy in East Asian women compared to Caucasian women, suggesting that the egg quality is not different between races.

While I recommend every patient closely weighs the benefits of a fresh versus frozen embryo transfer, an East Asian woman choosing a fresh embryo transfer should consider a protocol that calls for a reduction in the dose of gonadotropins leading up to her egg retrieval (even if it impacts the number of eggs harvested) in an effort to mitigate the effects of stimulation on her uterine environment.

That said, in the US Asian IVF population, heterogeneity of subpopulations prompt further delineation of at-risk populations for reduced IVF outcomes. Similarly, duration of infertility, lower BMI, and higher estradiol response to gonadotropin stimulation suggest biologic origins to differences in reproductive outcomes.