Women undergoing fertility treatment who eat high-fat diets may lower their odds of conceiving a child, a new federally funded study shows.
Harvard School of Public Health researchers found women with a high intake of dietary saturated fats produced fewer mature eggs for in-vitro fertilization and had lower IVF live birth rates. Those whose diets included more monounsaturated fats increased their odds of a live birth.
"Different types of fat are known to have different effects on biological processes which may influence the outcome of assisted reproduction – such as underlying levels of inflammation or insulin sensitivity,” said lead researcher Dr. Jorge Chavarro, a professor of nutrition and epidemiology at Harvard. “However, it is not clear at this moment which biological mechanisms underlie the associations we found.
"While these results are interesting, this is the first time to our knowledge that dietary fats have been linked to treatment outcome in IVF. So it is important that our results are replicated in other studies before making strong recommendations about fat intake to women having infertility treatment."
The study – funded by the National Institutes of Health and presented at an annual meeting of the European Society of Human Reproduction and Embryology – tracked nearly 150 women undergoing IVF at the Massachusetts General Hospital Fertility Center.
Researchers compared the effects of dietary fat – classified as total, saturated, monounsaturated, polyunsaturated, omega 6, omega 3 and trans – on the women’s health and fertility. They found high levels of saturated fat reduced the number of mature eggs that could be retrieved and fertilized, and that polyunsaturated fat consumption was linked with poorer embryo quality.
But women with higher intakes of healthier monounsaturated fat in their diets were nearly 3.5 times more likely to have a healthy child, after IVF, than those with the lowest intakes.
Previous studies have linked dietary fat intake to reproductive health problems, researchers noted. For example, trans-fats have been associated with ovulatory infertility and miscarriage, while saturated fats have been tied to lower sperm counts. But Chavarro’s study is the first to examine the effects of dietary fat intake on the outcome of fertility treatment.