Level and determinants of high fertility in two contrasting populations in Nigeria

This study examined levels and determinants of high fertility in the north-west and south-west zones in Nigeria. The study utilized 2013 nation-wide survey data on women aged 15-49 years (n=11,300). Data were analysed using ANOVA, logistic-regression, Brass P/F-ratio, Brass-relational Gompertz fertility and survival analysis models. About 44.4% of women in the north-west had high fertility (CEB≥5) compared to 26.9% in the south-west. The refined TFR, childbearing transition probabilities and progression rate were higher in the north-west (prr=0.2686) than south-west (prr=0.1709). The extent at which the age location of childbearing in the north-west (α=-0.003, StdE=0.083) differs from the standard was higher than south-west (α=-0.032, SE=0.95), but the fertility distribution across ages in the south-west was narrower. The odds of high fertility was higher in the north-west (OR= 2.18, C.I=1.99-2.37, p<0.001) than south-west. This odds barely changed when other factors such as age, age at first-sex, age at first-birth, modern contraceptive use, wealth quintile, education, religion, ethnicity, sex preference and ideal family size were controlled for. Fertility level was higher in the north-west than south-west. Improving women’s education in the north-west may facilitate low fertility in the region.