Association between Maternal Hemoglobin Levels During Pregnancy and Neonatal Birth Weight: A Cross-Sectional Observational Study

Abstract

Introduction: Reduced maternal hemoglobin (maternal anemia) is a common condition among pregnant women worldwide, with consequences that extend beyond the mother to adversely affect neonatal outcomes—most notably suboptimal birth weights. This study aimed to examine how hemoglobin concentrations measured in the final weeks of pregnancy relate to birth weight outcomes in newborns.

Objectives: To evaluate the relationship between maternal hemoglobin concentrations in late pregnancy and neonatal birth weight, and to examine the risk of low birth weight across different categories of maternal anemia severity.

Methods: A cross-sectional observational study was conducted on 120 pregnant women delivering at a tertiary hospital. Maternal hemoglobin levels were obtained from obstetric records within two weeks of delivery and categorized per WHO criteria as normal (≥11 g/dL), mild (10–10.9 g/dL), moderate (7–9.9 g/dL), and severe (<7 g/dL). Birth weight was recorded immediately after delivery. Pearson's correlation, ANOVA, and chi-square tests were used for analysis with SPSS v25.0.

Results: Anemia was identified in 48.3% of study participants. A statistically significant, though modest, direct association was observed between maternal hemoglobin concentration and neonatal birth weight (r=0.24, p=0.008). Mean birth weight declined with increasing anemia severity (p=0.012): non-anemic 3.08±0.42 kg, mild 2.92±0.39 kg, moderate 2.81±0.47 kg, and severe 2.65±0.51 kg. Neonates of anemic mothers had substantially higher rates of low birth weight (29.3% vs 8.1%, p=0.003).

Conclusions: This study demonstrates a positive correlation between maternal hemoglobin level and neonatal birth weight. Moderate or severe anemia is associated with markedly elevated risk of low birth weight, underscoring the critical need for routine antenatal anemia screening as a public health measure to optimize newborn health.