Link between high cholesterol, infertility studied

Couples who have high cholesterol may have a harder time conceiving, according to a study released in May by The Journal of Endocrinology and Metabolism.

In a study designed to evaluate the association between male and female serum lipid concentrations and time to pregnancy (TTP), researchers recruited 501 couples in the years 2005–2009 who were hoping to become pregnant in the near future.

The couples, who were from 16 counties in Michigan and Texas and who had discontinued contraception, were followed for 12 months or until pregnancy was detected.

Fecundability odds ratios (FORs) and 95% confidence intervals (CIs) were estimated after adjusting for age, body mass index, race, and education in relationship to female, male, and joint couple lipid concentrations.

Serum free cholesterol levels were higher on average among male and female partners of couples who did not became pregnant during the study follow-up (female, P = .04; male, P = .009), and levels in female partners were associated with significantly longer TTP in models based on both individual and couples concentrations (individual models: FOR 0.98, 95% CI 0.97, 0.99; couple models: FOR 0.98, 95% CI 0.97, 0.99). Male free cholesterol concentrations were associated with TTP only in the couple-based models (FOR 0.98, 95% CI 0.97, 0.99). Sensitivity analyses suggested that the observed associations were unlikely to be explained by potential unmeasured confounders such as diet.

“We’ve long known that high cholesterol levels increase the risk for heart disease,” said the study’s first author, Enrique Schisterman, PhD, in a Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) press release. Dr. Schisterman is chief of the epidemiology branch at the NICHD. “In addition to safeguarding their health, our results suggest that couples wishing to achieve pregnancy could improve their chances by first ensuring that their cholesterol levels are in an acceptable range.”

Schisterman EF, Mumford SL, Browne RW, Boyd Barr D, Chen Z, Buck Louis GM. Lipid concentrations and couple fecundity: the LIFE Study. JCEM. DOI: http://dx.doi.org/10.1210/jc.2013-3936