Changing scenario of birthweight in south India

Abstract

Reducing incidence of low birthweight and increasing mean birthweights are now considered seriously in the national action plans. Comparison of birthweights obtained over two decades from the representative random segments of rural and urban areas of North Arcot Ambedkar district, Tamil Nadu, India, were studied. Although statistically significant (p < 0.001), the mean birthweight shows only a marginal increase of 70 g from 2774.5 g (+/- 500.2) in 1969-73 to 2845.4 g (+/- 451.0) in 1989-93. The mean birthweight stratified by area and gender also revealed similar increase. On the other hand, the proportion of low birthweight (< 2500 g) newborns reduced significantly from 27.2% to 15.9% in rural and 19.1% to 10.8% in urban area over the decades (p < 0.001). The increase in the mean birthweight and the decline in the percentage of low birthweight newborns over the years was greater in rural than the urban community, but the rural newborns continued to weigh lesser than their urban counterparts.

PIP: Biostatisticians compared birth weight data of 2782 live singletons in the rural area of K.V. Kuppam and 2302 live singletons in the town of Vellore born during 1969-1973 with birth weight data of 2377 and 2407 singletons, respectively, born during 1989-1993 to examine changes in birth weight distributions in these rural and urban areas of North Arcot Ambedkar district in Tamil Nadu State, India. Between the two study periods, the mean birth weight increased in the rural area from 2717 g to 2794.74 g and in the urban area from 2843.93 g to 2895.74 g (p 0.001). It was lower in the rural area than in the urban area in 1989-1993 (2794 vs. 2895 g). Rural males gained the most (78.56 g vs. 59.49 g for urban males, 69.69 g for rural females, and 44.58 g for urban females). Nevertheless, the mean birth weight of all gender/residence groups increased significantly (p 0.001 for rural males and females; p 0.01 for urban males; and p 0.05 for urban females). Low birth weight (LBW: 2500 g) was less common in 1989-1993 than in 1969-1973 (15.9% vs. 27.2%; p 0.001). It was also less common in urban areas in 1989-1993 than in 1969-1973 (10.8% vs. 19.1%; p 0.001). Infants born weighing 2500-3249 g increased by 12% in the rural area and by 9% in the urban area (p 0.001). The percentage of infants weighing at least 3250 g in both areas did not change. During both periods, this group of infants was more common in the urban area than in the rural area (18.3% and 12.4%). Another study observed that the percentage of hospital deliveries in the rural and urban areas increased significantly between 1969-1973 and 1989-1993 (18.3-57.4% in the rural area and 53-84.2% in the urban area; p 0.001). These findings suggest that the minimal, yet significant, increase in birth weight over 20 years was mainly due to the reduction in the proportion of LBW infants.