title: Lactation, nutrition, and postpartum amenorrhea in lowland Papua New Guinea.
abstract: Prolonged on-demand breast feeding is known to delay the resumption of postpartum ovarian cyclicity. At present, however, little is known about the factors that influence the effectiveness of breast feeding as a natural contraceptive. Here, I examine the effects of maternal nutritional status on the duration of postpartum amenorrhea in two socioeconomic groups of Au forager-horticulturalists of lowland Papua New Guinea. Although women in both groups continue to breast-feed their offspring for approximately three and one-half years, well-nourished wage-earning Au women experience their first postpartum menses just over one year earlier (median = 12.5 months) than their more poorly nourished traditional counterparts (median = 26.6 months). Probit analyses are used to demonstrate that, even after controlling for time since delivery, maternal age, parity, and supplementation of infants' diets, the duration of postpartum amenorrhea is significantly (p < 0.05) negatively associated with indexes of maternal fat mass. No association between indexes of maternal lean body mass and the duration of postpartum amenorrhea were found. The results of this study suggest that components of maternal nutritional status, in particular, adiposity, play an important role in influencing fecundity in human populations.
authors.affiliation: Department of Anthropology, University of Washington, Seattle, WA 98195, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Tracer
mesh_terms: D000568:Amenorrhea / Q000453:epidemiology; D001942:Breast Feeding; D003906:Developing Countries; D005260:Female; D006801:Humans; D008423:Maternal Age; D009512:New Guinea; D009749:Nutrition Surveys; D010298:Parity; D049590:Postpartum Period; D011247:Pregnancy; D012307:Risk Factors; D012959:Socioeconomic Factors