Maternal prepregnancy anthropometric measures as a factor influencing neonatal birth weight

BACKGROUND: Maternal anthropometric measures before pregnancy are critical factors influencing neonatal birth weight and pregnancy outcomes. Specifically, a low maternal body mass index (BMI) increases the risk of low birth weight, whereas an elevated BMI is associated with fetal macrosomia and delivery complications. Investigating this relationship is essential for developing regional fetal growth standards and improving perinatal outcomes.

AIM: To assess the impact of maternal prepregnancy BMI on neonatal birth weight using regional data from women residing in the Kirov Region.

METHODS: A retrospective observational single-center study was conducted, including 5,161 pregnant women. Participants were categorized into three groups based on their prepregnancy BMI: underweight (<18.5 kg/m²), normal weight (18.5–24.9 kg/m²), and overweight (25.0–29.9 kg/m²). Women with obesity (BMI ≥30 kg/m²) were excluded. Maternal anthropometric data and neonatal birth weight were analyzed. Statistical methods included analysis of variance, Tukey’s test, Pearson correlation analysis, and multiple linear regression.

RESULTS: Significant differences in neonatal birth weight were observed across maternal BMI categories (p < 0.001). Mean birth weight increased with maternal BMI: 3,050 g ± 380 g (underweight), 3,300 g ± 400 g (normal BMI), and 3,550 g ± 420 g (overweight). A moderate positive correlation was found between maternal body weight and neonatal birth weight (r = 0.32; p < 0.001). Multiple linear regression analysis confirmed that both maternal weight and height were significant predictors of neonatal birth weight (p < 0.001).

CONCLUSION: Maternal prepregnancy BMI is a significant determinant of neonatal birth weight. Monitoring and maintaining BMI within the normal range before conception may contribute to improved perinatal outcomes.