Abstract Background Low dietary diversity can contribute to undernutrition, impacting gestational weight gain (GWG) and increasing the risk of low birth weight (LBW). Objective This study investigates the relationships between maternal dietary diversity, dietary quality, GWG, and LBW in a cohort of singleton pregnant mothers in Jordan. It was hypothesized that higher dietary diversity and appropriate GWG would correlate with a reduced likelihood of LBW and that "minimum dietary diversity for women (MDD-W)" and "prime diet quality scores (PDQS) " would have both indirect and direct effects on birth weight, mediated by GWG. Methods The prospective study involved 198 singleton pregnant mothers aged 19 to 45, segmented into three groups by trimester (66 women per trimester). Dietary diversity was assessed using the MDD-W and the PDQS. GWG was classified as appropriate, excess, or inadequate based on pre-pregnancy body mass index (BMI). Birth weights, lengths, and head circumferences of neonates were measured. Results Mothers with MDD-W > 5 and PDQS > 21 had significantly higher average birth weights and lengths compared to those with lower scores (MDD-W: 3.1 ± 0.6 vs. 2.6 ± 0.5 kg; PDQS: 3.0 ± 0.6 vs. 2.6 ± 0.5 kg; MDD-W: 49.8 ± 1.7 vs. 48.1 ± 1.7 cm; PDQS: 49.2 ± 1.8 vs. 48.1 ± 1.8 cm). Significant predictors of LBW included GWG for pre-pregnancy BMI, previous LBW deliveries, PDQS, and family income. Inadequate GWG was significantly associated with LBW. GWG significantly mediated the relationship between MDD-W (B = 0.067, P < 0.001, 95% CI 0.059–0.076), PDQS (B = 0.069, P < 0.001, 95% CI 0.06–0.077), and birth weight. Each score increase in MDD-W was associated with a 0.141 kg increase in birth weight (B = 0.141, P < 0.001, 95% CI 0.093–0.189), compared to a 0.041 kg increase for each PDQS score (B = 0.041, P < 0.001, 95% CI 0.025–0.058). Conclusions Our findings indicated that both MDD-W and PDQS are associated with birth weight, with higher scores correlating with increased GWG and birth weight. Notably, dietary diversity and GWG relative to pre-pregnancy BMI emerged as robust predictors of birth weight at delivery.
Al-Bayyari et al. (2025) studied this question.