Maternal risk factors associated with low birth weight among women 15-35 years in hospital births of Karachi, Pakistan : a case control study

Date of Award


Document Type


Degree Name

Master of Science in Epidemiology & Biostatistics (MSc Epidemiology & Biostats)


Community Health Sciences


BW (LBW) is an important and potentially preventable public health problem. It is the major determinant of neonatal and infant mortality in developing countries and it contributes largely to the overall burden of childhood mortality and morbidity. Although medical advances have played a major role in lowering infant mortality, the impact on the prevalence of LBW appears to have been minimal. The objective of this study was to evaluate the modifiable maternal risk factors associated with LBW among women age 15 - 35 years in hospital births of Karachi. This was a retrospective case control study carried out in the general wards of three hospitals of Karachi that draw patients from urban, suburban and rural areas. Cases were defined as mothers of newborns weighing less than or equal to 2.5 kilograms while controls were defined as mothers of newborns weighing greater than 2.5 kilograms at the time of birth. 262 cases and 262 controls of age 15 - 35 years without a known medical illness who delivered live-born singleton baby through vaginal delivery or caesarian sections without congenital malformations and with the gestational age between 37-42 weeks at the general wards of the selected hospitals were enrolled from hospital records within one day of delivery. Fetal factors such as preterm delivery, multiple pregnancy, and congenital abnormalities were not included in the study. Information was gathered regarding demographic and socioeconomic status, previous pregnancies, antenatal care during current pregnancy, morbidity during pregnancy, maternal nutritional status, strenuous physical activity and smoking. The odds ratios of anemic mothers and maternal iron supplement use during pregnancy to deliver low birth weight baby were (OR 6.2; 95% CI3.56, 10.80) and (OR 2.88; 95% CI 1.83, 4.54) respectively. With every 1 kg increase in maternal post partum weight the odds of low birth weight baby decreased (OR 0.97; 95% CI 0.95, 0.99). Odds was greater among females than male babies (OR 1 .59; 95% CI 1.09, 2.32). With every one year increase in maternal age the odds increased (OR 1.03; 95% CI 0.98, 1.07). However, strenuous working conditions, maternal food consumption, antenatal care, socio-demographic factors and history of previous pregnancies were not associated with the higher odds of low birth weight. Maternal anemia, iron intake and postpartum weight are related to newborns' birth weight. Reducing malnutrition among childbearing women should not be confined to interventions only during pregnancy. A life cycle approach to women's nutrition is not only important to their health but also to the health of their children and families. Women should be assessed for diet adequacy during family planning visits (hemoglobin measurement, diet history); education should be provided in elementary and secondary schools on nutrition and health care.

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