Decoding fertility behaviour of married women in Zambia: A multipronged analysis of bio-demographic, socio-economic and intermediate factors.

Despite national efforts and a decrease in total fertility rate, Zambia's fertility remains high compared to global and regional averages. While previous research has examined the influence of bio-demographic and socio-economic factors, it has neglected the role of overlooked intermediate variables such as age at first marriage, contraception use, and abortion. This study investigated the influence of these variables, while controlling for bio-demographic and socio-economic factors, on women's fertility behaviour in Zambia. The study drew upon data from three cross-sectional Zambia Demographic Health Surveys (2007, 2013-14, 2018) to investigate fertility behaviour among 18,299 married women, measured by the number of children ever born (CEB). Descriptive and inferential statistical analyses, including Analysis of Variance and Negative Binomial regression, were conducted using Stata 14.2 to identify factors associated with women's fertility behaviour. The regression results are presented as adjusted incidence rate ratios with confidence intervals. Married Zambian women's fertility behaviours, as measured by CEB are concerning, and exhibit patterns influenced by intermediate factors like age at first marriage and abortion. Early marriage, specifically before the age of 18, is associated with higher likelihood of having more CEB than those who married at 18 years or above (AIRR = 1.10, 95% CI: 1.07-1.14 in 2007; AIRR = 1.10, 95% CI: 1.10-1.12 in 2013; and AIRR = 1.07, 95% CI: 1.05-1.10). Conversely, married women who reported having had an abortion were more likely to have fewer CEB. In 2018, women with a history of abortion had lower likelihood of higher CEB compared to those without (AIRR = 0.94, 95% CI: 0.91-0.97). Besides, demographic and socio-economic factors such as age, education level, geographic location, and decision-making autonomy were found to significantly impact women's fertility behaviour. This study shows that the two intermediate variables of age at first marriage and a history of prior abortion are more influential on women fertility behaviour than contraception among married women in Zambia. To effectively address stalled fertility and improve women's reproductive health, policies should address early marriage, enhance access to sexual reproductive healthcare, and empower women to enable them make informed reproductive decision-making.