MATERNAL RISK FACTORS ASSOCIATED WITH LOW BIRTH WEIGHT

Abstract

Background: Low birth weight (LBW), defined as a birth weight of less than 2500 grams, remains one of the most significant public health challenges worldwide and is a major determinant of neonatal morbidity and mortality. According to the World Health Organization, approximately 15–20% of all newborns globally are born with low birth weight, accounting for more than 20 million births annually (WHO, 2023). Low birth weight is associated with an increased risk of neonatal death, impaired growth and development, childhood stunting, poor cognitive outcomes, and chronic diseases later in life (Adugna & Worku, 2022; Blencowe et al., 2019). Maternal factors such as young maternal age, low body mass index, short maternal stature, anemia, preeclampsia, adverse obstetric history, and short inter-pregnancy interval have been identified as important contributors to low birth weight in various populations. However, limited local evidence is available regarding these risk factors among Pakistani women, particularly in Balochistan.

Objective: To determine the association between maternal risk factors and low birth weight among term singleton neonates delivered at a tertiary care hospital in Quetta, Pakistan.

Methods: A hospital-based case-control study was conducted at the Department of Gynecology and Obstetrics, Bolan Medical Complex Hospital, Quetta. A total of 390 mothers were enrolled, including 195 cases (mothers delivering live-born singleton term neonates with birth weight <2500 g) and 195 controls (mothers delivering live-born singleton term neonates with birth weight 2500–4000 g). Data regarding maternal age, height, weight, body mass index (BMI), anemia, preeclampsia, bad obstetric history, residence, and inter-pregnancy interval were collected using a structured proforma. Statistical analysis was performed using SPSS version 25.0. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to identify factors associated with low birth weight.

Results: The mean maternal age was 25.8 ± 4.7 years among cases and 27.4 ± 4.9 years among controls. Maternal height <150 cm (OR=2.81, 95% CI: 1.68–4.71, p<0.001), maternal BMI <18.5 kg/m² (OR=2.43, 95% CI: 1.45–4.08, p=0.001), anemia (OR=2.92, 95% CI: 1.85–4.61, p<0.001), preeclampsia (OR=3.37, 95% CI: 1.76–6.45, p<0.001), inter-pregnancy interval <2 years (OR=2.11, 95% CI: 1.36–3.28, p=0.002), and bad obstetric history (OR=2.54, 95% CI: 1.43–4.49, p=0.001) were significantly associated with low birth weight. Residence and maternal age did not demonstrate statistically significant associations after adjustment for confounding factors.

Conclusion: Maternal nutritional status, short stature, anemia, preeclampsia, adverse obstetric history, and short inter-pregnancy interval were significantly associated with low birth weight. Early identification and management of these risk factors during antenatal care may contribute to reducing the burden of low birth weight and improving neonatal outcomes in resource-limited settings.