By: Rebecca Morris-Ostrom for Uterus1
Black and Asian women have a lower success rate with assisted reproductive techniques than their white and Hispanic counterparts, researchers declared. Two studies presented at the 2004 annual meeting of the American Society for Reproductive Medicine (ASRM) led to this conclusion.
Researchers led by Dr. David Granger at the University of Kansas in Wichita analyzed the results of approximately 80,000 assisted reproductive (ART) cycles. A cycle is defined as the period beginning when the patient starts taking hormones and ending when the embryo is implanted in her uterus. They found that the live birth rate (babies born divided by the number of cycles completed) for the fresh donor cycles was 25.7% among all the women. However, calculating the numbers by race, white and Hispanic women had live birth rates of 26.3% and 26.7%, respectively; the rates for black and Asian women were 18.7% and 20.7%. They also found that the rates of miscarriage were lowest for white women (14%), as opposed to 16% for Asian and Hispanic women, and 22% for black women. These disparities only appeared when using ART with fresh embryos; trying to get pregnant naturally or using ART with frozen embryos resulted in more even pregnancy rates.
A second study, led by Dr. Karen Purcell at the University of California, San Francisco, studied the records from 1200 ART cycles that took place between 2001 and 2003. They discovered that Asian women had a lower pregnancy rate than other women. The Asian women also tended to be older than their non-Asian counterparts, although the researchers adjusted for that difference when reporting the statistics. Data available from Hong Kong and Taiwan also shows a lower IVF success rate for Asian women than for non-Asian women.
There are a number of factors that may explain the differences. However, no concrete explanation for the difference has been proven. Black women tend to be more overweight and have a higher incidence of fibroids (benign uterine tumors) and uterine disease, all of which make bearing children more difficult. Studies have shown that black women get fibroids at a rate of up to nine times that of white women. Fibroids tend to appear at a younger age and grow larger in black women as well. Asian women have a higher rate of polycystic ovaries and endometriosis, and Asian men often have very low sperm counts. In addition, the large amount of fresh fish in the Asian diet may mean a higher level of mercury in their bodies. All of these factors make bearing children more difficult.
All other things being comparable, the reduced rate of pregnancy and birth for Asian and black women is equivalent to adding five years of age to a white woman trying to conceive and give birth.
This study contradicts a claim at the ASRM’s 2002 annual meeting. The report, based on several studies, stated, “A patient’s race does not appear to have any effect on the outcome of IVF procedures if other factors are controlled for.” These studies were much smaller, examining fewer than 2000 patients altogether.