Friday, 6 May, 2011

Lower IVF Success Rates Widely Reported In Patients Of African Origin May Be Consequence Of Genetic Predisposition Towards Autoimmunity

In vitro fertilization (IVF) pregnancy rates, also known as "IVF success rates" are related to specific genotypes and races/ethnicities, according to new research conducted by a New York City-based IVF center. It has long been known that IVF success rates differ amongst different races/ethnic groups. This new study suggests that predisposition to autoimmune disease may be the cause for these differences.

Despite general improvement in outcomes of fertility treatments, disparities between races/ethnicities have actually increased. Prevalence of infertility also differs in that African women experience infertility more frequently than Caucasians and Asians. Causes for these differences have remained largely unknown.

This new study, just published in the prestigious medical journal PLoS One, was conducted by the Center for Human Reproduction (CHR) in New York, NY, and involved 339 Caucasian, Asian and African women. As previously widely reported in the medical literature, African patients demonstrated significantly lower IVF pregnancy rates, compared to Asian and Caucasian patients, even after controlling for age and BMI. African patients also demonstrated the highest rates of the recently described FMR1 (fragile X mental retardation) gene sub-genotype het-norm/low, which the same group of researchers previously reported to be statistically highly associated with autoimmunity. Asian women, with lowest prevalence of het-norm/low experienced the highest pregnancy rates after IVF.

"We have previously associated this specific FMR1 sub-genotype with an approximately 50% reduction in IVF pregnancy chances," explains David Barad, MD, MS, one of the study's senior authors, and Clinical Director of ART at CHR. "This new finding is in line with our previous studies on this specific FMR1 sub-genotype."

"The association of FMR1 genotypes and risk for autoimmunity presents evidence that autoimmunity may be associated with lower pregnancy rates in IVF in general," adds Norbert Gleicher, MD, the study's second senior author, and Medical Director of CHR. "Autoimmunity may, thus, also be at least partially responsible for the racial/ethnic disparities in infertility prevalence and treatment outcomes."