Summary:
Infertility affects 12-15% of couples globally and is influenced by environmental and lifestyle factors such as obesity, air pollution, and diet. Emerging evidence suggests that women’s preconception dietary patterns may impact fertility. Previous studies have associated adherence to diets rich in vegetables, fish, legumes, and low in processed foods, as well as Mediterranean-style diets, with higher pregnancy and live birth rates. However, inconsistencies in dietary scoring methods have led to conflicting findings. This study is a prospective cohort analysis which looked at women aged 18-45 undergoing infertility evaluation and treatment between 2007 and 2019. Dietary intake was assessed before treatment using a food frequency questionnaire, and adherence to eight predefined dietary patterns was calculated: three Mediterranean-style scores, the Healthy Eating Index, the Alternate Healthy Eating Index, the American Heart Association (AHA) index, the DASH index, and a plant-based diet score. Clinical outcomes assessed were live birth, clinical pregnancy, and pregnancy loss. Overall, adherence to the eight dietary patterns was not associated with the probability of achieving clinical pregnancy or live birth. However, higher adherence to the AHA dietary pattern was associated with a lower risk of pregnancy loss. Women in the highest quartile of AHA diet adherence had a 28% probability of total pregnancy loss compared with 41% in the lowest quartile. Other dietary patterns showed similar trends, except the plant-based diet, which was not associated with pregnancy loss risk. These findings suggest that preconception adherence to the AHA dietary pattern may reduce the risk of pregnancy loss during infertility treatment. Promoting a heart-healthy diet may support reproductive outcomes by reducing early pregnancy loss.
Abstract:
Importance: Increasing evidence suggests that specific foods and nutrients may improve infertility treatment outcomes in women. However, less is known about the role of dietary patterns. Objective To investigate whether women’s adherence to a priori–defined dietary patterns promoted for the prevention of chronic conditions is associated with outcomes of infertility treatment. Design, Setting, and Participants This prospective cohort study was conducted at a fertility center at an academic medical center in Boston, Massachusetts. Women undergoing infertility treatment cycles, including intrauterine insemination cycles and in vitro fertilization with or without intracytoplasmic sperm injection were included. Data were collected from January 2007 to October 2019, and data were analyzed from February to December 2022. Exposures Women’s pretreatment diet was assessed with a validated food frequency questionnaire from which 8 a priori–defined scores were calculated (higher score indicates greater adherence): (1) Trichopoulou Mediterranean diet, (2) alternate Mediterranean diet, (3) Panagiotakos Mediterranean diet, (4) Healthy Eating Index, (5) Alternate Healthy Eating Index, (6) American Heart Association (AHA) index, (7) Dietary Approaches to Stop Hypertension index, and (8) plant-based diet. Main Outcomes and Measures The adjusted probability of clinically relevant outcomes (live birth as a primary outcome and clinical pregnancy and pregnancy loss as secondary outcomes) was evaluated across quartiles of adherence to each dietary pattern using multivariable generalized linear mixed models to account for repeated cycles. Results This analysis included 612 women with a median (IQR) age of 35.0 (32.0-38.0) years. There was no association between women’s adherence to the 8 a priori dietary patterns and probability of clinical pregnancy or live birth following in vitro fertilization or intrauterine insemination. However, an inverse association was found between adherence to AHA dietary pattern and risks of total and clinical pregnancy loss. Among women who became pregnant during the course of infertility treatment, the adjusted probabilities of pregnancy loss in the lowest and highest quartile of the AHA dietary pattern were 0.41 (95% CI, 0.33-0.50) and 0.28 (95% CI, 0.21–0.36), respectively (P for trend = .02). The corresponding adjusted probabilities of clinical pregnancy loss were 0.30 (95% CI, 0.22-0.39) and 0.15 (95% CI, 0.10-0.23) (P for trend = .007). A similar pattern was observed for all other dietary patterns, with the exception of the plant-based diet pattern. Conclusions and Relevance Findings of this cohort study suggest that preconception adherence to the AHA diet may be associated with a lower likelihood of pregnancy loss during the course of infertility treatment.
Article Publication Date: 18/08/2023
DOI: 10.1001/jamanetworkopen.2023.29982
