Repetitive Failed IVF, Researchers Unlock Medical Mystery
Despite modern advances in infertility treatments which has made it possible for post-menopausal women to give birth to their own grandchildren and scientists to create sperm in a lab – one medical mystery still has had researchers scratching their heads. When it comes to getting pregnant via in vitro fertilization (IVF), African Americans have far less success than their Caucasian and Asian counterparts, leading to multiple failed IVF treatments. Up until now, the cause of this has been largely unknown. However, a new study now reveals that this ethnic disparity may actually be caused by autoimmunity.
Autoimmunity Causing Infertility in African American Women
Researchers from New York based IVF research center examined 399 Caucasian, Asian and African women in their study in order to try and identify why racial disparities exist among infertility treatments. Each of the women in the study were tested for a specific genotype, known as FMR1, which has previously been associated with autoimmunity and a lower risk for pregnancy. After controlling for other factors such as BMI, age, and hormones the researchers discovered that African Americans had the highest incidence of the FMR1 genotype and autoimmunity along with the lowest rate of pregnancy after IVF.
This therefore lead researchers to conclude that FMR1 related autoimmunity may be responsible for a higher incidence of failed IVF treatments in African American women.
FMR1 and Autoimmunity
The FMR1 geneotype, is one of many variations of expressions of the FMR, or fragile x mental retardation, gene. FMR genotypes vary among women and medical studies have shown the FMR1 genotype with an increased risk for failed 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 the Center for Human Reproduction. “This new finding is in line with our previous studies on this specific FMR1 sub-genotype.”
Furthermore, more recent research has shown that those with a FMR1 geneotype also have higher rates of autoimmunity, which can be any number of diseases in which the body's immune system acts against itself. Therefore, researchers have been able to draw the conclusion that it is actually FMR1 which causes autoimmunity which in turn causes infertility.
In the present study, the fact that African Americans have both the highest incidences of autoimmunity, FMR1 genotype and failed IVF treatments lead researchers to conclude that African women are more genetically predisposed to FMR1 and therefore autoimmunity related infertility.
“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 in press release statement. “Autoimmunity may, thus, also be at least partially responsible for the racial/ethnic disparities in infertility prevalence and treatment outcomes.”
This study appears in the most recent online edition of the PLoS ONE medical journal.
Resource: Gleicher N, Weghofer A, Lee IH, Barad DH, 2011 Association of FMR1 Genotypes with In Vitro Fertilization (IVF) Outcomes Based on Ethnicity/Race. PLoS ONE 6(4): e18781. doi:10.1371/journal.pone.0018781