Risk factors for preterm and term low birthweight in Ahmedabad, India

Abstract

To identify and quantify risk factors for preterm and term low birthweight (LBW) we conducted a hospital-based case-control study, linked with a population survey in Ahmedabad, India. The case-control study of 673 term LBW, 644 preterm LBW cases and 1465 controls showed that low maternal weight, poor obstetric history, lack of antenatal care, clinical anaemia and hypertension were significant independent risk factors for both term and preterm LBW. Short interpregnancy interval was associated with an increased risk of preterm LBW birth while primiparous women had increased risk of term LBW. Muslim women were at a reduced risk of term LBW, but other socioeconomic factors did not remain significant after adjusting for these more proximate factors. Estimates of the prevalence of risk factors from the population survey was used to calculate attributable risk. This analysis suggested that a substantial proportion of term and preterm LBW births may be averted by improving maternal nutritional status, anaemia and antenatal care.

PIP: In 1987-1988, researchers compared data on 1317 low birth weight (LBW) infants and 1465 control infants born in 3 teaching hospitals in Ahmedabad, India to calculate attributable risk (AR) for factors contributing to low birth weight. 673 of the infants were full term yet LBW due to intrauterine growth retardation. 644 of LBW infants were preterm births. They also conducted a population survey in Ahmedabad to estimate the prevalence of risk factors. LBW prevalence stood at 30%. Low maternal weight, poor pregnancy history, lack of prenatal care, clinical anemia, and hypertension were all significant independent risk factors for term and preterm LBW infants (p.05). Primiparous women were more likely to have a term LBW infant than other women (p.05). Interpregnancy intervals =or 6 months was more likely to result in delivery of a preterm LBW infant than longer interpregnancy intervals (p.05). Muslim women were at a much lower risk of delivering a term LBW infant than were Hindu women (p.05). Other than primiparity for term LBW infants (AR=21.9%), maternal weight between 41-45 kg was the single greatest risk factor for LBW (AR=21.5% for term and 19.8% for preterm). Yet low maternal weight had greater adjusted odds ratios (OR) than did maternal weight between 41-45 kg (OR=6.9 and 6.2 vs. OR=3.1 and 2.9). Maternal weight was used to measure nutritional status. Clinical anemia also carried a high Ar, especially for term LBW infants (3.7-8.2% vs. 2.8-7.3% for preterm infants). Another risk factor with considerable AR was no prenatal care (5.8% for term and 14.4% for preterm). These results emphasized the need for health and nutrition interventions to reduce the incidence of both preterm and term LBW infants in urban India.