The influence of age at first birth on population growth: the case study of Zanzibar

Age at first birth is a demographic variable, which influences fertility. Fertility, on the other hand, is a variable that influences population growth. In many countries, the postponement of first birth has been counted responsible for fertility decline. Women who start childbearing in low ages are often found to have high fertility, while those who start childbearing at high ages have low fertility. Therefore, high age at first birth may be linked to fertility decline. Studies done by the Demographic Health Surveys in some less developed countries found that the proportion who start childbearing before age 20 end up with high fertility. These studies conclude that in order to effect fertility decline, one of the methods could be to raise age at first birth to 29 years. Observations of age cohorts in Zanzibar show that age at first birth has been also found that the proportion who start childbearing before age 20 is high and this group ends up with high fertility. Use of contraception in Zanzibar is very low. Only 5.25 percent of women in childbearing ages currently use contraceptives. Among these women, only 1.3 percent contraception before having their first birth, which indicates that a very small percentage of women use contraception in order to delay first birth. Age at first birth has been observed to rise with increasing level of education. Thus, encouraging women to have higher education may be one of the ways to raise age at first birth.