Birthweight and gestational age centiles in South Indian newborns

Abstract

Background: India has recently gone through a vast technological and economic revolution which has influenced all sections of society. The study was undertaken to determine any changes in the pattern of intrauterine growth in South Indian babies over three decades compared with national and international studies. Objectives: To construct new 2015-2017 centile charts for birthweight in babies born from 28 to 42 gestational weeks in the metropolitan city of Bangalore, South India compared with an earlier South Indian centile chart constructed in 1983 at Christian Medical College and Hospital (CMCH), Vellore, India and other national and international studies. Design, setting and method: This is a retrospective study of two cohorts. The first cohort consisted of 4,426 consecutive live births from January to December 1983, at CMCH, a tertiary referral hospital in South India. The second cohort consisted of 2,708 consecutive live births from January 2015 to May 2017 at Shifaa Hospital, a multispecialty centre, in the metropolitan city of Bangalore, South India, about 300 km from CMCH. The chief outcome measure was birthweight centiles according to gestational age. The two cohorts of singleton live births were analysed to determine the mean birth weights, gestation and centile growth patterns. Data were obtained from labour room records. Results: Among a total of 4,426 live births during 1983, the mean birthweight was 2881g and among 2,708 live births during 2015-2017, the mean birth weight was 2873g, a difference of 8g. The mean gestation was 38.8 weeks in the former and 38.2 weeks in the latter study respectively. The centile growth curves among the two cohorts revealed almost similar percentile weight distribution except for preterm 31-36 weeks gestation, where birthweights in the 2015-2017 cohort were 200-300g higher compared to the 1983 cohort. However, the 90thcentile curve, at term 38-40 weeks revealed an increase of 200-300g weight gain in 1983 cohort which thereafter plateaued, with 300g weight gain at 40-41 weeks in the 2015-2017 cohort. Comparison was also made with both national and international centile intrauterine growth curves. Conclusions: The 2015-2017 centile charts for birthweight in babies born from 28 to 42 gestational weeks in the metropolitan city of Bangalore, South India had almost similar growth curves and mean birthweights compared to the 1983 South Indian centile chart indicating an inherent genetic predisposition for the small Indian baby. The updated centiles for births during 2015-2017 provide a more valid tool to assess South Indian fetal growth. Sri Lanka Journal of Child Health, 2019; 48(2): 140-145