Impact of infant mortality on tempo of fertility in Sudan.

This study hypothesizes that child mortality is a key factor affecting fertility in the Sudan. It estimates levels and trends of infant mortality and fertility based on the 1989 and 1980 Sudan Demographic and Health Surveys. The analysis examines the demographic and socioeconomic differences in infant mortality and fertility. The analysis focuses on the length of birth interval by birth order in order to avoid the problem of reverse causation between infant mortality and fertility. The surveys covered about 80% of total population. 47.2% of the study population was illiterate. Findings indicate that women tended to replace a child who died in the first year of life and to replace the child quickly after its death. Death in the first year of life reduced the average second birth interval from 26.6 to 20.4 months. Death of the sixth child in infancy reduced the seventh birth interval from 28.3 to 21.2 months. Birth intervals of rural women did not vary by birth order. Birth intervals increased as urban women moved to higher parities. Among rural women birth intervals were reduced by about 6 months at all parities after a preceding death. Among urban women the birth interval was shortened by over 6 months at higher parities. Among educated women the second birth interval after the death of a first birth was reduced by 4.3 months. At the fourth birth interval the birth interval was further reduced. Womens age was clearly associated with the tempo of fertility when child mortality and birth interval were accounted for. The birth interval among young women averaged about 27.5 months. Birth intervals of older women averaged about 28.5 months. All women experienced shorter birth intervals after the death of their first child compared to women with a surviving first birth.