Maternal dietary diversity and dietary quality scores in relation to adverse birth outcomes in Tanzanian women

Abstract

Background: Preterm birth (PTB), small for gestational age (SGA), and low birth weight (LBW) are risk factors for morbidity and mortality among infants. High-quality maternal diets during pregnancy may protect against these adverse birth outcomes.

Objectives: The aim of this study was to prospectively examine the association of maternal dietary diversity and quality during pregnancy with birth outcomes among women in Dar es Salaam, Tanzania.

Methods: We analyzed data from 7553 HIV-negative pregnant women enrolled in a multivitamin trial at 12-27 weeks of gestation. Dietary intake was assessed using 24-h dietary recalls. Dietary diversity scores (DDS; range: 0-10) were computed as the number of food groups consumed by women, using FAO's Minimum Dietary Diversity for Women index. The Prime Diet Quality Score (PDQS; range: 0-42) assessed maternal diet quality based on consumption of 21 healthy and unhealthy food groups. Log binomial regression methods were used to assess associations of DDS and PDQS with PTB, SGA, LBW, and fetal loss.

Results: In the previous 24 h, 99.9% of all women had consumed cereal and staples, 57.9% meats, 4.7% eggs, and 0.5% nuts and seeds. Median DDS was 3.0 (IQR: 2.5-3.5). For the PDQS, all women consumed ≥4 servings/wk of green leafy vegetables and refined grains. Higher DDS was associated with lower risk of SGA (RR highest compared with lowest quintile: 0.74; 95% CI: 0.62, 0.89). Higher PDQS was associated with lower risk of PTB (RR highest compared with lowest quintile: 0.55; 95% CI: 0.46, 0.66), LBW (RR: 0.53; 95% CI: 0.40, 0.70), and fetal loss (RR: 0.53; 95% CI, 0.34, 0.82).

Conclusions: PDQS was inversely associated with PTB, LBW, and fetal loss, and DDS was inversely associated with SGA. These findings suggest that in addition to dietary diversity, diet quality should be considered as important in understanding dietary risk factors for poor birth outcomes.This trial was registered at clinicaltrials.gov as NCT00197548.

Keywords: Minimum Dietary Diversity for Women; Prime Diet Quality Score; Tanzania; dietary diversity; fetal loss; low birth weight; pregnancy outcomes; preterm; small for gestational age.