Study finds diet adherence reduces pregnancy loss

Study finds diet adherence reduces pregnancy loss | Image Credit: © nadianb - © nadianb - stock.adobe.com.

According to a recent study published in JAMA Network Open, the risk of pregnancy loss during infertility treatment is reduced by adherence to the American Heart Association (AHA) diet.

Infertility affects approximately 12% to 15% of couples worldwide, with the prevalence of infertility increasing over time. There are multiple factors which impact fertility, and data has indicated an association between fertility and diet.

Studies have found an association between diet and birth outcomes following infertility treatment, but these studies did not have a consistent scoring system for defining adherence. These studies also lacked data on the impact of diet adherence on multiple outcomes.

Investigators conducted a study to determine the association between adherence to 8 common diets and chronic conditions associated with infertility treatment. Participants included women aged 18 to 45 years receiving evaluation and treatment for infertility at the Massachusetts General Hospital (MGH) Fertility Center.

Patients were enrolled in the Environment and Reproductive Health (EARTH) study, evaluating determinants of fertility. Women in the EARTH study completed questionnaires, where data was obtained on demographic characteristics, medical and reproductive history, and diet. These women also received an anthropometric evaluation.

Women who discontinued care at MGH were excluded from the analysis. This led to 612 women in the final sample, completing a total of 1572 treatment cycles. These included 804 intrauterine insemination (IUI) cycles and 768 in vitro fertilization (IVF) cycles.

Preconception diet was the primary exposure of the study, evaluated through a semiquantitative food frequency questionnaire including over 131 foods and beverages. Women reported the frequency at which they consumed each item.

Adherence to 8 dietary pattern scores was analyzed. There included the Trichopoulou Mediterranean diet (TMD), alternate Mediterranean diet (AMD), Panagiotakos Mediterranean diet (PMD), Healthy Eating Index (HEI), Alternate Healthy Eating Index (AHEI), AHA 2020 dietary goals index, Dietary Approaches to Stop Hypertension (DASH) index,and plant-based diet (PBD).

Live birth per initiated treatment cycle was the primary outcome of the story. Total pregnancy loss, clinical pregnancy, and clinical pregnancy loss were reported as secondary outcomes. Covariates included height and weight, lifestyle factors, medical history, physical activity, and reproductive health.

Participants were aged a median 35 years and had a median body mass index of 23.4. Of patients, 9.7% were Asian, 4.3% Black, 82.8% White, and 3.3% another race or ethnicity. Most had never smoked and had a college degree, with female factor infertility being the most common initial primary infertility diagnosis in 38.7% of participants.

Modest to high correlation was found between all dietary patterns, with TMD and AMD scores having the highest correlation. When evaluating separately or when combining data from IVF or IUI cycles, associations were not found between patient adherence to any of the 8 dietary patterns and odds of clinical pregnancy or live birth after infertility treatment.

Reduced risks of total and clinical pregnancy loss were associated with adherence to the AHA dietary pattern when combining data from the IVF and IUI cycles, with an adjusted probability of total pregnancy loss of 0.41 in the lowest quartile of the AHA pattern. In comparison, the adjusted probability in the highest quartile was 0.28.

For clinical pregnancy loss, the lowest quartile had an adjusted probability of 0.30 and the highest an adjusted probability of 0.15. Similar associations were found in the DASH, TMD, AMD, PMD, and HEI and AHEIA diet scores, though these associations were weaker. PMD was not associated with pregnancy loss.

These results indicated an association between diet adherence and pregnancy loss among women with infertility treatment. Investigators recommended future studies evaluate the effects of nutritional interventions on human fertility.

Reference

Salas-Huetos A, Mitsunami M, Wang S, et al. Women’s adherence to healthy dietary patterns and outcomes of infertility treatment. JAMA Netw Open. 2023;6(8):e2329982. doi:10.1001/jamanetworkopen.2023.29982