Could fertility problems be in your blood? Women with type O blood may have lower egg counts and poorer egg quality—and thus, more difficulty becoming pregnant—compared to women of other blood types, according to findings presented October 25, 2010, before a meeting of the American Society of Reproductive Medicine.
Conducted by researchers at the Albert Einstein College of Medicine in New York, the study tracked a group of 560 women who were being treated for infertility. Comparing women by blood type, researchers noted that women with blood type O were twice as likely to have follicle-stimulating hormone levels above the normal threshold. As a report in the UK’s Telegraph newspaper explains, FSH is produced by the body to stimulate the follicles in the ovaries that produce eggs—a high FSH level as a key indicator of having a low egg count. While FSH normally increases when women enter their 30s and 40s, the current study discovered that FSH was higher in women with type O blood, regardless of age.
In contrast, researchers found that women with type A blood appeared to have more and better quality eggs than all other blood types. "Those with blood type O were twice as likely to have an FSH level over 10 [considered the threshold between normal and raised levels] than those with blood types other than O. We found that women with the A blood group gene were protected from this effect," says lead author Dr. Edward Nejat, in an interview with the Telegraph.
Does type O blood make your chances for pregnancy hopeless? Not at all, say other fertility experts who point out that researchers only studied FSH, but did not look at other fertility tests such as Antral follicle counts and the anti-Mullerian hormone fertility test.
"It's a very interesting finding, but I don't think anybody should hit the panic button if they're type O," says Dr. Elan Simckes, of Fertility Partnership in St. Louis, in an interview with AOL Health.