Dietary diversity during pregnancy is associated with reduced risk of maternal anemia, preterm delivery, and low birth weight in a prospective cohort study in rural Ethiopia

Abstract

Background: Anemia during pregnancy is a leading nutritional disorder with serious short- and long-term consequences for both the mother and the fetus.

Objective: The objective was to investigate the association between dietary diversity during pregnancy and maternal anemia, low birth weight (LBW), preterm birth (PTB), and stillbirth in rural Ethiopia.

Design: We conducted a prospective cohort study and enrolled 432 pregnant women in their first antenatal care visit (24-28 gestational weeks); 374 women completed the follow-up. By using the FAO Women's Dietary Diversity Scores (WDDSs), subjects were categorized into "inadequate" (WDDS <4) and "adequate" (WDDS ≥4) groups and were followed until delivery. Primary outcomes were maternal anemia, birth weight, term delivery, and stillbirth.

Results: The attrition rate was 13.7% and was balanced across the 2 groups. The proportion of women consuming dairy, animal-source foods, fruits, and vegetables including vitamin A-rich ones was higher in the adequate than in the inadequate WDDS group (P < 0.05). The overall incidence of maternal anemia increased from 28.6% to 32.4% during the follow-up period. The overall proportion of LBW, PTB, and stillbirth were 9.1%, 13.6%, and 4.5%, respectively. After control for baseline differences, women in the inadequate group had a higher risk of anemia [adjusted RR (ARR: 2.29; 95% CI: 1.62, 3.24], LBW (ARR: 2.06; 95% CI: 1.03, 4.11), and PTB (ARR: 4.61; 95% CI: 2.31, 9.19) but not of stillbirth (ARR: 2.71; 95% CI: 0.88, 8.36) than women in the adequate group (P < 0.05).

Conclusions: A WDDS of ≥4 food groups during pregnancy was shown to be associated with lower risk of maternal anemia, LBW, and PTB. Population-based controlled trials of various options to improve dietary diversity are needed before conclusive recommendations can be made. This trial was registered at clinicaltrials.gov as NCT02620943.

Keywords: anemia; dietary diversity; low birth weight; pregnancy outcome; preterm; stillbirth.