Socioeconomic mediation of birth interval duration in a Papua New Guinea population.

Abstract

A probit analysis of birth intervals and supplementary feeding found that there were significant differences in birth intervals among infants of wage earners and infants of traditional subsistence foragers and small scale farmers (Au) in Papua New Guinea. The median duration of breast feeding was 43.0 +or- 1.8 months among Au and 42.7 +or- 6.2 months among wage earners. The examination of suckling data (289 suckling bouts among 15 Au and 8 wage earning mothers) found that Au infants suckled less often: 1.9 bouts per hour among Au infants and 2.8 bouts per hour among infants of wage earners. Food supplementation was offered among Au infants at 7 months and infants of wage earners at 1 month. The multivariate probit analysis of the determinants of birth interval found that maternal nutritional status had direct and important effects on the resumption of menses. A longer period of time since delivery was found to be related to an increased probability of a return to menses. Higher maternal age and higher parity were related to a lower probability of resumption of menses. Mothers whose infants received additional food supplementation were more likely to have resumed menses. A higher number of maternal skinfolds was found to be significantly related to resumption of menses when controls were included for time since delivery maternal age and parity and infant supplementation. The results suggested that socioeconomic status differences in birth interval as measured by postpartum amenorrhea were related to nutritional status in a non-contracepting population.