Male Infertility among the Gwembe Tonga of Zambia

Athena Pantazis, University of Washington

Population measures of fertility and infertility are generally constructed from birth histories of women and limited to the population of women. However, the Gwembe Tonga Research Project collected data on both women and men's births from 1956-1995 for four Gwembe Tonga villages in Zambia. This analysis applied Larsen's and Menken's subsequently infertile measure to the male birth histories to obtain an estimate of male infertility in the Gwembe Tonga population. Additionally, Gwembe Tonga estimates were compared with estimates for women's infertility computed using Zambia Demographic and Health Survey birth histories from 1992, 1996, 2001-02, and 2007). Discrete event history analysis was used to obtain predicted probabilities of being infertile by age by sex and over time. The odds of infertility increased steadily with age for both men and women, and across all datasets. Women’s odds of infertility were 3 times that of men’s. Odds of infertility also increased over time.