Associations between Maternal and Infantile Factors and Neonatal Growth Metrics: A Large-scale, Retrospective Study

Abstract

Objective: The primary aim of this large-scale, retrospective study was to identify the maternal and infantile factors influencing neonatal growth metrics within the 1st month of life. Materials and Methods: Data were collated from the Sina Electronic Health System between 2015 and 2018. The study employed the World Health Organization (WHO) Z-score system for categorizing neonatal growth and utilized logistic regression models to explore associations between maternal and infant characteristics and neonatal growth metrics. Results: The study comprised 137,548 neonates, with a slight male predominance (51%). An overwhelming 98% of infants were breastfed. The logistic regression analysis revealed male gender as a significant predictor for higher weight-for-age Z-score (WAZ) (odds ratio [OR] = 1.268, P < 0.001), height-for-age Z-score (HAZ) (OR = 1.316, P < 0.001), and weight-for-height Z-score (WHZ) scores (OR = 1.137, P = 0.015). In addition, vaginal delivery was strongly associated with higher WAZ (OR = 1.176, P < 0.001), HAZ (OR = 2.109, P < 0.001), and WHZ scores (OR = 1.176, P = 0.003). The influence of breastfeeding was particularly noteworthy, with significant associations with higher WAZ (OR = 1.934, P < 0.001), HAZ (OR = 5.435, P < 0.001), and WHZ scores (OR = 1.558, P = 0.008). Conclusions: Our robust analysis substantiates the significant influence of male gender, vaginal delivery, and breastfeeding on neonatal growth metrics, as evidenced by elevated WAZ, HAZ, and WHZ scores. The findings provide a compelling argument for the promotion of natural birthing methods and breastfeeding, and they highlight the role of gender in neonatal growth outcomes during the initial month of life.