ORLANDO – A higher ratio of serum omega-6 to omega-3 fatty acids was associated with an improved chance of pregnancy through in vitro fertilization, according to a prospective cohort study.
The study, which investigated the relationship between serum levels of polyunsaturated fatty acids (PUFAs) and embryo implantation in women undergoing IVF, found no association between IVF success and any of the PUFAs alone, or total fatty acid levels.
Dr. Vasiliki A. Moragianni
"While interesting, our findings should not be interpreted to influence current clinical practice, as they were not the result of a clinical trial," said Antonina I. Frolova, an M.D./Ph.D. student in the department of obstetrics and gynecology at Washington University, St. Louis.
"Our study suggests that PUFAs may also play a role in endometrial receptivity, but again, to our knowledge there is no clinical trial data to guide clinicians in counseling women on their intake of specific PUFAs to improve pregnancy rates in IVF," Ms. Frolova said in an interview. She presented the study at the annual meeting of the Society for Gynecologic Investigation.
The measurement of PUFA levels is currently not a part of standard assisted reproductive technology (ART) practice, said Dr. Vasiliki A. Moragianni, a reproductive endocrinologist at Beth Israel Deaconess Medical Center in Boston, who moderated the session.
The study "certainly adds a valuable piece of information and can be used as a springboard for more targeted investigations," Dr. Moragianni said in an interview. Once strong evidence and more data become available, "we will be able to make specific dietary recommendations and/or measure certain markers that can help improve couples’ fertility," she said.
Using the Women and Infants Health Specimen Consortium, Ms. Frolova and her colleagues measured the fasting serum levels of PUFAs in 200 women undergoing IVF. The women were divided into two groups: those who conceived and those who did not.
PUFA measurements included levels of linoleic acid (LA), alpha-linoleic acid (ALA), eicosapentaenoic acid (EPA), arachidonic acid (AA), and docosahexaenoic acid (DHA).
Researchers used standard regression to find out if any of the serum PUFAs was associated with pregnancy. They also analyzed the relationship between omega-6 to omega-3 ratios (LA:ALA) and (AA:EPA) and the odds of pregnancy
Although they found no association between individual PUFAs and the odds of pregnancy through IVF, they found a significant difference in LA:ALA ratios between women who conceived after their IVF cycle and those who did not (14.5 vs. 13.8, respectively; P = .03).
Women in the highest tertile of LA:ALA ratios had the highest chance of pregnancy compared with women with the lowest LA:ALA ratios (odds ratio, 2.5).
Embryo implantation was also weakly associated with LA:ALA ratios (P = .003), the researchers reported in the abstract.
There was no association between pregnancy and AA:EPA in this study, Ms. Frolova said. However, AA:EPA was positively correlated with the LA:ALA ratio (r = 0.4, P less than .001).
"Our findings are significant, as they suggest dietary intake of specific PUFAs may be altered to benefit women undergoing IVF," Ms. Frolova said. "Specifically, the study suggests that omega-3 and omega-6 PUFAs may have opposing effects in the endometrium, similar to other tissues."
She noted that further studies are needed to elucidate this mechanism, adding, "Prior to making any clinical recommendations, however, we would like to see a clinical trial investigating supplementation of certain PUFAs and pregnancy outcomes after IVF."
Ms. Frolova and Dr. Moragianni said they had no disclosures.
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