NIH Study Links Cholesterol Levels to Lower Fertility

Couples with high levels of cholesterol have lower fertility, a new study reveals.

The study, conducted by researchers at the National Institutes of Health and colleagues, found that couples where both partners had high cholesterol levels had lower fertility as compared to couples with normal cholesterol levels.

Also, couples in which woman had high cholesterol level - took longer to conceive than couples with cholesterol in healthy range.

Cholesterol is the waxy substance found in all cells. The body uses cholesterol to make several substances including hormones.

The Royal College of Obstetricians and Gynaecologists (RCOG) had earlier said that obese women must lose weight before getting pregnant to avoid problems during gestation and delivery.

"We've long known that high cholesterol levels increase the risk for heart disease," said the study's first author, Enrique Schisterman, Ph.D., 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, according to a news release. "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."

The study is published in the Journal of Endocrinology and Metabolism.

Data for the study came from 501 couples who were trying to conceive, but were not diagnosed with infertility. All the participants were enrolled in the Longitudinal Investigation of Fertility and the Environment, which is looking into the relation between fertility, lifestyle and exposure to chemicals.

Researchers used blood samples of the participants to determine total cholesterol levels. The study didn't differentiate between type of cholesterol such as HDL cholesterol, LDL cholesterol and triglycerides.

The team followed the couples until pregnancy or one year from when the couples started trying to conceive.

Researchers found that couples that didn't get pregnant during the study duration had the highest levels of cholesterol. Researchers accounted for racial differences, age and education and found that cholesterol levels were independently associated with fertility problems.

"From our data, it would appear that high cholesterol levels not only increase the risk for cardiovascular diseases, but also reduces couples' chances of pregnancy," Dr. Schisterman said.