Dietary Diversity and Gestational Weight Gain are Predictors of Birth Outcomes: A Cohort Study in Nigeria

Abstract

Background: Maternal malnutrition contributes to adverse birth outcomes in low- and middle-income countries, yet evidence from Nigeria remains limited. Objective: We tested the directional hypothesis that higher maternal dietary diversity would be associated with greater third-trimester weight gain and improved birth outcomes among pregnant women in Ota, Ogun State, Nigeria. Materials and Methods: A longitudinal study of 200 women attending public and private facilities completed three 24-hour dietary recalls; foods were classified into ten groups to compute dietary diversity scores (DDS) categorized as low (≤3), moderate (4–5), or high (≥6). Last-trimester weight gain (LTWG) was derived from weights at 28, 30, and 32 weeks. Birth weight was classified as low (<2.5 kg), normal (2.5–3.5 kg), or high (>3.5 kg). Associations were examined using chi-square tests and binary logistic regression. Result: Overall, 32% had low DDS and 3.5% had low LTWG. All low-birth-weight cases (2.5%) occurred among women with low DDS (p = 0.015) and low LTWG (p < 0.01). Lunch time was the only dietary habit marginally associated with adverse birth outcomes (p =0.05). DDS remained a significant predictor of birth outcome (β= -1.595, AOR=0.213; 95% CI [0.077, 0.592], p=0.003), indicating 78.7% decrease in the odds of adverse birth outcome among women with good DDS. Conclusion: Findings support the hypothesis that greater dietary diversity is linked to higher third-trimester weight gain and better birth outcomes in this population. Integrating dietary diversity counseling and weight monitoring into routine antenatal care may help reduce the risk of low birth weight in similar settings