In a unique study, published in February's Fertility & Sterility, examining possible impact of ethnicity on successful outcomes of in vitro fertilization (IVF), researchers have concluded that IVF simply isn't working as well for women of Asian descent.
They're not sure as to the reasons yet, but one theory posited is that it's more cultural and environmental than biological or genetic.
Lead author Karen Purcell MD of Fertility Physicians of Northern California in San Jose and her team reviewed both national and local data that compared over 25,000 white women and more than 1,400 Asian women, all of whom went through IVF in the United States. Making sure to control for variables like the type of treatment and medications used, number of eggs retrieved, the women's ages, hormone levels, and male infertility causes, the study found that the Asian women were 31 percent less likely to get pregnant than the Caucasians.
One theory on the cause: because of traditional Asian diets that are rich in seafood, the women could have higher blood levels of methyl mercury, known to be toxic to embryos.
An important factor that was not considered in the data mining for this study: the male partner's ethnicity and whether it impacted IVF success.
Until more studies explore the relationships between ethnicity and IVF success, this report's authors advise fertility experts to at least let their patients of Asian descent know that their outcome statistics may vary from the numbers they frequently read on websites and in advertisements.