Maternal Dietary Habits and Prenatal Micronutrient Supplementation Patterns as Joint Predictors of Continuous Infant Birth Metrics in Western Kenya

Background Optimal prenatal conditions are vital for positive clinical delivery metrics, yet the comparative relationships of specific maternal behaviors with infant metrics remain heavily debated. This study evaluated how maternal age, dietary habits, and prenatal micronutrient supplement patterns concurrently predict infant birth weight and gestational age at delivery. Methods A descriptive, quantitative, cross-sectional design was utilized with a cohort of N = 234 maternal-infant pairs at Siaya County Referral Hospital in Western Kenya. Baseline characteristics included maternal age, fruit and vegetable intake frequency, and micronutrient supplement utilization patterns (never used, used one type, or used multiple types). Data were analyzed using multi-factor Multivariate Analysis of Variance (MANOVA), multivariable linear regressions, Pearson Chi-Square tests, and multivariable logistic regression. Results Full-term gestations reached 90.6% (n = 212) and normal birth weights reached 90.2% (n = 211). The omnibus MANOVA demonstrated that maternal supplementation pattern was the only factor significantly associated with joint infant outcomes (p = .006), showing independent associations with birth weight (p = .001) and gestational age (p = .029). Complete absence of supplementation was linked to the highest proportion of low birth weight (38.5%) and preterm delivery (30.8%). Use of a single formulation was associated with the lowest proportions of low birth weight (4.7%) and preterm delivery (5.8%), whereas multiple-type use showed numerically higher proportions (10.2% and 8.6%); this contrast was not formally tested. Finally, preterm birth was heavily clustered with low birth weight, showing a 54.64-fold increase in the crude odds of restricted infant mass (p < .001, 95% CI: 16.0–187.0). Conclusion Prenatal micronutrient supplement patterns were associated with infant birth weight and gestational age in this single-center cross-sectional study. Single-formulation use was associated with the lowest observed proportions of preterm birth and low birth weight. These exploratory findings require confirmation in prospective studies with verified dosing before informing supplementation guidance.