Birth weight pattern in Karnataka.

The pattern of birth weight is described among births recorded in rural maternity homes in coastal areas of Udupi taluk in South Kanara district in Karnataka state, India. Literacy of the study area was 78.5%, and female literacy was 73.0%. The mean age at marriage was 21.4 years. Over 90% of mothers received some prenatal care. Contraceptive prevalence was 43%. The study area had six rural maternity homes that each served a population of about 10,000 people. The homes were well equipped with trained nurse-midwives, medical rooms, and equipment, and were connected by roads and telephones with Kasturba Hospital. High risk cases were transported by air to Kasturba Hospital. Birth weight was recorded with a UNICEF infant lever balance scale within one hour of delivery. Between July 1985 and June 1988, 4498 singleton live births were recorded: 2308 (51.3%) boys and 2190 (48.7%) girls. 80% weighed between 2500 and 3400 g. 13.3% were low birth weight of under 2500 g, and 0.4% were very low birth weight of under 1500 g. The mean birth weight was 2823 g: 2850 g for boys and 2765.4 for girls. The mean birth weight increased with maternal age; it also increased with increased parity and increased gestation age. The lowest birth weight of 2767.7 g occurred among first births; the highest of 2897.6 g was among births to women with multiple births. 91.3% were born between 37-40 weeks, and 7.5% were preterm. There were statistically significant differences in the mean birth weights by gender. 9.1% of births were to teenagers, and 69% of mothers were 20-29 years old. 30% of births were first births, and 51% were second and third births. The small family norm appeared to be accepted by this study population.