A couple’s cholesterol levels may play a part in how long it takes them to conceive, according to a recent study.
Between 2005 and 2009, the researchers tracked 501 couples who were attempting to conceive. They were followed for 12 months or until a pregnancy was detected with human chorionic gonadotropin (hCG). During follow-up, 69% of the couples became pregnant (fecundability), 11% did not and 20% withdrew from the study.
All participants had a lipid analysis that included cholesterol, free cholesterol, phospholipids, triglycerides, and total lipids. For both men and women, age was significantly associated with free cholesterol levels, mean BMI increased as free cholesterol quartiles increased, and participants in lower quartiles for free cholesterol reported more vigorous exercise than did those in higher quartiles.
After adjustment for age, BMI, and race and education, free cholesterol (fecundity odds ratio 0.983) and total lipids (fecundity odds ratio .998) in women were significantly associated with time to pregnancy. No serum lipid components in men were significantly associated with time to pregnancy. With couples’ concentrations modeled together, free cholesterol was significantly associated with time to pregnancy (fecundity odds ratio 0.984), as was male free cholesterol (fecundity odds ratio 0.984).
“Of the five lipid components evaluated, free cholesterol was robustly associated with reduced fecundity when modeling female serum lipids individually or in a couple-based approach independent of BMI,” the authors wrote. “Male free cholesterol concentrations were also an independent risk factor for reduced fecundability, irrespective of female lipid levels.”
The next question is whether reducing the free cholesterol and total lipids will improve the fecundability rate. It is not a very practical thing to try to do because all one can rely on is dietary changes and exercise, which is certainly worth a try. Using statins which is often required when younger people have high cholesterol is not a practical approach in women at least because the statins cannot be used in pregnancy and should probably not be used in anticipation of pregnancy.