Protein-rich food intake and risk of spontaneous abortion: a prospective cohort study

• Published in: European journal of nutrition 2022-08, Vol.61 (5), p.2737-2748
• Main Authors: Wesselink, Amelia K., Willis, Sydney K., Laursen, Anne Sofie Dam, Mikkelsen, Ellen M., Wang, Tanran R., Trolle, Ellen, Tucker, Katherine L., Rothman, Kenneth J., Wise, Lauren A., Hatch, Elizabeth E.
• Format: Article
• Language: English
• Subjects: Abortion; Chemistry; Chemistry and Materials Science; Cohort analysis; Dairy products; Food; Food intake; Meat; Miscarriage; Nutrition; Original Contribution; Pregnancy; Proteins; Questionnaires; Seafood
• ISSN: 1436-6207; 1436-6215
• DOI: 10.1007/s00394-022-02849-4

Purpose Diet quality is increasingly recognized as important for human reproductive capacity. We studied the association between intake of protein-rich foods and risk of spontaneous abortion (SAB). Methods During 2013–2020, we recruited pregnancy planners from the United States and Canada (Pregnancy Study Online; PRESTO) and Denmark (SnartForaeldre.dk; SF). Participants completed a baseline questionnaire and a validated cohort-specific food frequency questionnaire. We estimated preconception intake of red meat, poultry, processed meat, seafood, eggs, plant-based proteins, and dairy from individual foods and mixed recipes. We included 4,246 PRESTO and 2,953 SF participants who reported a pregnancy during the study. Data on SAB were derived from questionnaires and population registries. We used Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CI), representing the effect of substituting one type of protein-rich food for another. Results SAB risk was 23% in PRESTO and 16% in SF. In PRESTO, substitution of seafood with other protein-rich foods was associated with higher SAB risk [for example, the HR for replacing 100 g of seafood/week with 100 g of red meat was 1.10 (95% CI 1.00, 1.20)]. In contrast, in SF, substituting seafood with other protein-rich foods was associated with lower SAB risk [HR for replacing 100 g of seafood/week with 100 g of red meat was 0.89 (95% CI 0.82, 0.98)]. Other protein-rich food substitutions were not meaningfully associated with SAB risk. Conclusions Preconception intake of protein-rich foods was largely unrelated to SAB risk, with the exception of seafood, which was associated with higher risk of SAB in Denmark, but a lower risk in North America.