infertility and high cholesterol
May 21, 2014

Infertility Could Be Linked To High Cholesterol In Would-Be Parents

redOrbit Staff & Wire Reports - Your Universe Online

Couples who are having trouble conceiving might want to have their cholesterol levels checked, according to new research published online Tuesday by The Journal of Clinical Endocrinology and Metabolism.

According to the study authors, high cholesterol could impair fertility, and couples in which each partner had elevated levels took the longest time to conceive. Furthermore, cases in which the woman had a high cholesterol level but not the man also took a greater amount of time to successfully conceive when compared to couples in which both the male and female partners had cholesterol levels that fell in the acceptable range.

“We've long known that high cholesterol levels increase the risk for heart disease,” explained first author Dr. Enrique Schisterman, chief of the Epidemiology Branch at the Eunice Kennedy Shriver National Institute of Child Health and Human Development (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.”

Cholesterol, which is a waxy fat-like substance found within all of the body’s cells, is used to produce vitamin D, hormones and several other types of substances, the researchers explained. Approximately 71 million Americans over the age of 18, or one-third of all adults in the US, have elevated low-density lipoprotein (LDL) or “bad cholesterol” levels, according to the Centers for Disease Control and Prevention (CDC).

The population-based prospective cohort study looked at the pregnancy rate of 501 heterosexual couples from four counties in Michigan and 12 counties in Texas between 2005 and 2009. Each of the couples was involved in the Longitudinal Investigation of Fertility and the Environment (LIFE) study, which examined the link between fertility and exposure to environmental chemicals and lifestyle, and all of them were actively trying to conceive.

Over the course of the 12-month study, 347 of the couples became pregnant, while 54 did not conceive and 100 others withdrew from the study (including some who changed their mind about having a child). Dr. Schisterman and his colleagues measured the cholesterol levels of each potential mother and father by testing a blood sample that was taken at the outset of the study.

Instead of directly measuring HDL cholesterol, LDL cholesterol and triglycerides separately, the investigators opted to measure the total and free amounts of cholesterol in the blood. Based on their findings, they found that couples where one or both partners had high cholesterol took significantly longer to conceive. They believe that blood cholesterol could be linked to fertility because it is used to manufacture the sex hormones testosterone and estrogen.

“Couples in which both the prospective mother and father had high cholesterol levels took the longest time to conceive a child,” said Dr. Schisterman, who was joined on the study by experts from NICHD, Emory University and the University of Buffalo. “Our study also found couples in which the woman had high cholesterol and the man did not took longer to become pregnant than couples where both partners had cholesterol levels in the normal range.”