Couples with high cholesterol levels may have to wait longer to become parents, a new study finds.

When both the prospective moms and dads had high cholesterol levels, it took longer to conceive compared to those with lower cholesterol levels. The study also found the highest cholesterol levels among the couples who didn’t achieve pregnancy during the year-long study.According to a study by researchers at the National Institutes of Health, the University at Buffalo (New York), and Emory University in Atlanta.

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

Experts studied 501 couples from Michigan and Texas who were not being treated for infertility but were still trying to have a child. Women, ages 18 to 44, and men, who were over 18, provided blood samples. In general, those with high cholesterol either did not become pregnant or took a longer time to conceive. Among participants, researchers also discovered that Hispanic males had the highest cholesterol levels.

The study also found that couples where the woman had high free cholesterol levels and the male did not also took longer to have children than couples with normal cholesterol levels. This could mean that women, more so than men, are key in the regulation of cholesterol levels when dealing with infertility. Of course other couples with high levels experienced the same problems. That being said, other issues like drugs, alcohol use, and stress can still be big factors in infertility. The link between free cholesterol is new, as in the past doctors did not typically test for the levels when discussing fertility in couples.

The data showed that cholesterol not only affects the risk for cardiovascular disease, but monitoring such rates may help those trying to become pregnant, study author Dr. Enrique Schisterman said.