Background High-risk fertility behaviors (HRFBs) are common in African and South Asian countries and can potentially affect child survival. This study examines the high-risk fertility behaviors concerning child mortality across the countries. Method Data from a series of Demographic and Health Surveys from the year 1987 to 2016 from 24 South Asian and African countries (N=1,224,832) were included in this study. Four HRFB parameters - women’s age <18 or >=34 years at childbirth, birth spacing <24 months, and child order of birth >3, were categorized into three exposure levels: i) exposure to any HRFBs category (exposure to any of four parameters); ii) exposure to single and multiple HRFB category (a combination of two or more parameters); and iii) the specific type of HRFB category (either single or multiple HRFB categories). Bivariate descriptive analysis and a multivariate logistic regression model were used to examine the association between under-five child mortality and various measures of HRFBs. Results Our pooled data analysis reported that HRFBs was associated with an increased risk of under-five child mortality in Asian and African countries. Children of women exposed to HRFBs were at increased risk of under-five mortality by 77% (Adjusted Odds Ratio (AOR) = 1.771, 95% confidence interval (CI): 1.722 - 1.821). Children born within 24 months’ birth interval were four times more likely to die (AOR = 4.995, 95% CI: 4.842-5.152) than their counterparts. However, a single high-risk category was not associated with under-five mortality, and birth order was found to be a protective factor against under-five mortality. Age of women (<18 or >=34 years) was found to be a risk factor of Under-five child mortality in 16 countries. The association between under-five mortality risk and birth interval of less than 24 months was highly significant in all countries. Conclusion Women’s age at childbirth, birth interval, and birth order were significantly associated with under-five mortality. Quality care for women and newborns need to be ensured through investment in the healthcare system, and by promoting health services with more focus given to the valuable populations through sexual and reproductive health education programs and empowering women.

Background: Younger or older maternal age, short inter-pregnancy birth interval, and higher birth order of the child are considered to be high-risk fertility behaviour (HRFB). Under-five mortality being disproportionately concentrated in Asia and Africa, this study analyses the association between HRFB and under-five mortality in selected Asian and African countries.Methods: This study used Integrated Public Microdata Series-Demographic and Health Surveys (IPUMS-DHS) data from 32 countries in Sub-Saharan Africa, Middle East, North Africa, and South Asia from 1986 to 2017 (N=1,467,728). Previous evidence hints at four markers of HRFB: women’s age at the birth of index child <18 years or >34 years, short preceding birth interval (PBI) <24 months, and child’s birth order >3. Using logistic regression, we analysed the change in the odds of under-five mortality as a result of i) exposure to HRFB individually, ii) exposure to any single HRFB risk factor, iii) exposure to multiple HRFB risk factors, and iv) exposure to specific combinations of HRFB risk factors. Results: Mother’s age at the birth of index child <18 years and preceding birth interval (PBI) <24 months were significant risk factors of under-five mortality, while a child’s birth order >3 was a protective factor against under-five mortality. Presence of any single HRFB was associated with 1.067 times higher risk of under-five mortality (OR = 1.067; 95% CI: 1.042 - 1.090; P < 0.001). Presence of multiple HRFBs was associated with 1.392 times higher risk of under-five mortality (OR = 1.392; 95% CI: 1.355 - 1.431; P < 0.001). Some specific combinations of risky fertility behaviour such as younger maternal age (<18 years) and short preceding birth interval (PBI <24) significantly increased the odds of under-five mortality.Conclusion: Younger maternal age and short preceding birth interval significantly increase the risk of under-five mortality. This highlights the need for effective legislation to curb child marriages and increased public investment in reproductive healthcare with a focus on higher contraceptive use for an optimal interpregnancy interval.

Background: Smaller or older maternal age, smaller inter-pregnancy birth interval, and higher birth order of the child are considered to be high-risk fertility behaviour (HRFB). Under-five mortality being disproportionately concentrated in Asia and Africa, this study analyses the association between HRFB and under-five mortality in selected Asian and African countries. Methods: This study used Integrated Public Microdata Series-Demographic and Health Surveys (IPUMS-DHS) data from 32 countries in Sub-Saharan Africa, Middle East, North Africa, and South Asia from 1986 to 2017 (N=1,467,728). Previous evidence hints at four markers of HRFB: women's age at the birth of index child <18 years or >34 years, smaller preceding birth interval (PBI) <24 months, and child's birth order >3. Using logistic regression, we analysed the change in the odds of under-five mortality as a result of i) exposure to HRFB individually, ii) exposure to any single HRFB risk factor, iii) exposure to multiple HRFB risk factors, and iv) exposure to specific combinations of HRFB risk factors. Results: Mother's age at the birth of index child <18 years and preceding birth interval (PBI) <24 months were significant risk factors of under-five mortality, while a child's birth order >3 was a protective factor against under-five mortality. Presence of any single HRFB was associated with 1.067 times higher risk of under-five mortality (OR = 1.067; 95% CI: 1.042 - 1.090; P < 0.001). Presence of multiple HRFBs was associated with 1.392 times higher risk of under-five mortality (OR = 1.392; 95% CI: 1.355 - 1.431; P < 0.001). Some specific combinations of risky fertility behaviour such as younger maternal age (<18 years) and smaller preceding birth interval (PBI <24) significantly increased the odds of under-five mortality.Conclusion: Younger maternal age and small preceding birth interval significantly increase the risk of under-five mortality. This highlights the need for effective legislation to curb child marriages and increased public investment in reproductive healthcare with a focus on higher contraceptive use for an optimal interpregnancy interval.