Diet for preventing miscarriage? Best foods to eat reported in meta-analysis

For healthy women of reproductive age, sticking to a diet abundant in fruits, vegetables, seafood, dairy, eggs, and grain prior to conceiving helps minimize the chances of pregnancy loss, according to the results of a meta-analysis.

Across 20 studies involving 63,838 women, the odds of miscarriage were reduced among women with high periconceptional intake of the following food groups: fruits (odds ratio [OR], 0.39, 95 percent confidence interval [CI], 0.33–0.46), vegetables (OR, 0.59, 95 percent CI, 0.46–0.76), fruit and vegetables (OR, 0.63, 95 percent CI, 0.50–0.81), seafood (OR, 0.81, 95 percent CI, 0.71–0.92), dairy products (OR, 0.63, 95 percent CI, 0.54–0.73), eggs (OR, 0.81, 95 percent CI, 0.72–0.90), and cereal (OR, 0.67, 95 percent CI, 0.52–0.87). [Fertil Steril 2023;120:333-357]

On the other hand, the evidence was uncertain for meat, red meat, white meat, fat and oil, and sugar substitutes.

“We did not find evidence of an association between adherence to predefined dietary patterns and miscarriage risk,” the investigators said.

“However, a whole diet containing healthy foods as perceived by the trialists, or with a high Dietary Antioxidant Index score (OR, 0.43, 95 percent CI, 0.20–0.91) [was] associated with a reduction in miscarriage risk. In contrast, a diet rich in processed food was … associated with increased miscarriage risk (OR, 1.97, 95 percent CI, 1.36–3.34),” they added.

In addition, an overall dietary exposure that was high in quality with healthy nutrient sources and low in proinflammatory factors or unhealthy food groups such as highly refined, processed meat, or sugar substitutes had a protective effect on miscarriage risk.

These findings mostly agree with existing evidence on diet and other reproductive outcomes. Specifically, food groups that are commonly considered to be healthy, with high levels of essential nutrients, have protective effects on miscarriage risk. [Clin Nutr ESPEN 2020;36:1-9]

Holistic food choices

“Our review findings confidently demonstrate the lack of a predefined dietary pattern that is categorically superior to others, highlighting that strict adherence to a single predefined dietary pattern may not reliably optimize one’s reproductive health,” the investigators stated.

“Instead, the data suggest that clinicians should be recommending holistic food choices that are rich in healthy food groups with high antioxidant components and ideally devoid of unhealthy food groups that are highly refined, processed, and proinflammatory,” they continued.

Moreover, even if a dietary pattern is composed of mostly healthy food sources, it can still be too restrictive and lead to nutritional deficiencies, which can increase the risk of poor reproductive outcomes such as reduced birth weight. [Nat Med 2023;29:710-718]

For that reason, women who wish to reduce their risk of miscarriage should be urged to make dietary choices that are both healthy and balanced to meet nutritional demands, the investigators said.

More studies are required to establish whether the relationship between diet and miscarriage risk is causal. Accurately estimate the effectiveness of periconceptional dietary interventions is also crucial to better guide clinicians on which dietary advice should be provided during the critical stages of pregnancy establishment and development.