Maternal intake of inadequate dietary folate, and low serum folate levels during pregnancy are associated with increased risk of preterm birth in rural Ethiopia: a prospective cohort study

Abstract Inadequate intake of dietary folate is associated with an increased risk of preterm birth, but evidence is limited in low-income settings, including the study area. This study examines the association between maternal intake of inadequate folate and low serum folate levels during pregnancy and the risk of preterm birth in rural Ethiopia. A prospective cohort study examined the association of maternal intake of inadequate dietary folate and low serum folate levels during pregnancy and an increased risk of preterm birth. An assessment of dietary folate intake was conducted using 24-h dietary method at enrollment and each trimester to determine nutrient adequacy throughout the study. A blood sample was collected at their first prenatal visit and at term for serum folate analysis. Logistic regression analyses were fitted to identify the predictors of preterm birth among pregnant women. In this study, the average gestational age at birth was 37.50 weeks, and the preterm birth rate was 23.58%. Inadequate dietary diversity (< 5), dietary folate consumption below recommended levels, and malnutrition were associated with increased odds of preterm birth, with adjusted odds ratios (AOR) of 0.52 (95% CI: 0.301, 0.890), 0.84 (95% CI: 0.74, 0.93), and 1.105 (95% CI: 0.98, 1.24), respectively. Pregnant women with serum folate levels < 4.4 µg/l had 0.760 times higher odds of preterm birth compared to those with levels > 4.4 µg/l(AOR = 0.760, 95% CI: 0.552–0.933) adjusting for other variables. Preterm birth is a significant problem. Maternal intake of inadequate dietary folate during pregnancy indicated by low serum folate is strongly associated with preterm birth. Strengthening public health interventions, including providing additional food for pregnant mothers, ensuring iron and folic acid supplementations, food fortification with folate, dietary diversity and monitoring anthropometric indicators earlier during antenatal care, is crucial.