New evidence about effects of reproductive variables on child mortality in sub-Saharan Africa

Association between high-risk fertility behaviors and neonatal mortality in Ethiopia: A multilevel mixed-effects logit models from 2019 Ethiopian mini demographic and health survey

Objectives

This study aimed to explore the association between high-risk fertility behaviors and neonatal mortality in Ethiopia.

Study design

A community-based cross-sectional study was conducted using data from the 2019 Ethiopian Mini-Demographic and Health Survey.

Methods

Mixed-effects logit regression models were fitted to 5527 children nested within 305 clusters. The definition of high-risk fertility behavior was adopted from the 2019 EMDHS. The fixed effects (the association between the outcome variable and the explanatory variables) were expressed as adjusted odds ratios (ORs) with 95 % confidence intervals and measures of variation explained by intra-class correlation coefficients, median odds ratio, and proportional change invariance.

Results

The presence of births with any multiple high-risk fertility behaviors was associated with a 70 % higher risk of neonatal mortality (AOR = 1.7, (95 % CI: 1.2, 2.3) than those with no high-risk fertility behavior. From the combined risks of high-risk fertility behaviors, the combination of preceding birth interval <24 months and birth order four or higher had an 80 % increased risk of neonatal mortality (AOR = 1.8, (95 % CI, 1.2, 2.7) as compared to those who did not have either of the two. The 3-way risks (combination of preceding birth interval <24 months, birth order 4+, and mother's age at birth 34+) were associated with approximately four times increased odds of neonatal mortality (AOR (95 % CI:3.9 (2.1, 7.4)].

Conclusions

High-risk fertility behavior is a critical predictor of neonatal mortality in Ethiopia, with three-way high-risk fertility behaviors increasing the risk of neonatal mortality fourfold. In addition, antenatal follow-up was the only non-high fertility behavioral factor significantly associated with the risk of neonatal mortality in Ethiopia.

The effects of reproductive variables on child mortality in Ethiopia: evidence from demographic and health surveys from 2000 to 2016

BACKGROUND

Child mortality is a crucial indicator reflecting a country's health and socioeconomic status. Despite significant global improvements in reducing early childhood deaths, Southern Asia and sub-Saharan Africa still bear the highest burden of newborn mortality. Ethiopia is one of five countries that account for half of new-born deaths worldwide.

METHODS

This study examined the relationship between specific reproductive factors and under-five mortality in Ethiopia. A discrete-time survival model was applied to analyze data collected from four Ethiopian Demographic and Health Surveys (EDHS) conducted between 2000 and 2016. The study focused on investigating the individual and combined effects of three factors: preceding birth interval, maternal age at childbirth, and birth order, on child mortality.

RESULTS

The study found that lengthening the preceding birth interval to 18-23, 24-35, 36-47, or 48+ months reduced the risk of under-five deaths by 30%, 46%, 56%, and 60% respectively, compared to very short birth intervals (less than 18 months). Giving birth between the ages 20-34 and 35+ reduced the risk by 34% and 8% respectively, compared to giving birth below the age of 20. The risk of under-five death was higher for a 7th-born child by 17% compared to a 2nd or 3rd-born child. The combined effect analysis showed that higher birth order at a young maternal age increased the risk. In comparison, lower birth order in older maternal age groups was associated with higher risk. Lastly, very short birth intervals posed a greater risk for children with higher birth orders.

CONCLUSION

Not only does one reproductive health variable negatively affect child survival, but their combination has the strongest effect. It is therefore recommended that policies in Ethiopia should address short birth intervals, young age of childbearing, and order of birth through an integrated strategy.

Wealth inequalities in reproductive and child health preventive care in Mozambique: a decomposition analysis

Background

Assessing the gap between rich and poor is important to monitor inequalities in health. Identifying the contribution to that gap can help policymakers to develop interventions towards decreasing that difference.

Objective

To quantify the wealth inequalities in health preventive measures (bed net use, vaccination, and contraceptive use) to determine the demographic and socioeconomic contribution factors to that inequality using a decomposition analysis.

Methods

Data from the 2015 Immunisation, Malaria and AIDs Indicators Survey were used. The total sample included 6946 women aged 15–49 years. Outcomes were use of insecticide-treated nets (ITN), child vaccination, and modern contraception use. Wealth Index was the exposure variable and age, marital status, place of residence, region, education, occupation, and household wealth index were the explanatory variables. Wealth inequalities were assessed using concentration indexes (Cindex). Wagstaff-decomposition analysis was conducted to assess the determinants of the wealth inequality.

Results

The Cindex was −0.081 for non-ITN, −0.189 for lack of vaccination coverage and −0.284 for non-contraceptive use, indicating a pro-poor inequality. The results revealed that 88.41% of wealth gap for ITN was explained by socioeconomic factors, with education and wealth playing the largest roles. Lack of full vaccination, socioeconomic factors made the largest contribution, through the wealth variable, whereas geographic factors came next. Finally, the lack of contraceptive use, socioeconomic factors were the main explanatory factors, but to a lesser degree than the other two outcomes, with wealth and education contributing most to explaining the gap.

Conclusion

There was a pro-poor inequality in reproductive and child preventive measures in Mozambique. The greater part of this inequality could be attributed to wealth, education, and residence in rural areas. Resources should be channeled into poor and non-educated rural communities to tackle these persistent inequities in preventive care.

Association of breast feeding and birth interval with child mortality in Pakistan: a cross-sectional study using nationally representative Demographic and Health Survey data

OBJECTIVES

This study analysed the association between breast feeding (BF) and birth interval (BI) (both succeeding and preceding) with neonatal mortality (NM), infant mortality (IM) and under-5 mortality (U5M).

DESIGN

This cross-sectional study used data from the Pakistan Demographic and Health Survey 2017-2018.

SETTINGS

All provinces, Islamabad and Federally Administered Tribal Areas were included in the analysis.

PARTICIPANTS

A total of 12 769 children born to ever-married multiparous women aged 30-49 years who gave live birth within 5 years preceding the interview. Multiple births are not included.

DATA ANALYSIS

Multivariate logistic regression analysis was used.

RESULTS

We found that BF was associated with nearly 98% lower risk of NM (OR 0.015; 95% CI: 0.01 to 0.03; p<0.001), 96% lower risk of IM (OR 0.038; 95% CI: 0.02 to 0.06; p<0.001) and 94% lower risk of U5M (OR 0.050; 95% CI: 0.03 to 0.08; p<0.001). Compared with optimal preceding birth interval (PBI) (36+ months), short PBI (<18 months) was associated with around six times higher risk of NM (OR 5.661; 95% CI: 2.78 to 11.53; p<0.001), over five times risk of IM (OR 4.704; 95% CI: 2.70 to 8.19; p<0.001) and over five times risk of U5M (OR 4.745; 95% CI: 2.79 to 8.07; p<0.001). Disaggregating the data by child's gender, place of residence and mother's occupational status showed that being ever breast fed was associated with a smaller risk of NM, IM and U5M in all three disaggregations. However, the risk of smaller PBI <18 months was generally more pronounced in female children (NM and U5M) or when the children lived in rural areas (NM, IM and U5M). PBI <18 months was associated with greater risk of NM and IM, and smaller risk of U5M when mothers did a paid job.

CONCLUSION

This study's significance lies in the fact that it has found BF and BI to be consistent protective factors against NM, IM and U5M. Given Pakistan's economic constraints, optimal BF and BI are the most cost-effective interventions to reduce child mortality.

What have we learned about mortality patterns over the past 25 years?

In this paper, I examine progress in the field of mortality over the past 25 years. I argue that we have been most successful in taking advantage of an increasingly data-rich environment to improve aggregate mortality models and test pre-existing theories. Less progress has been made in relating our estimates of mortality risk at the individual level to broader mortality patterns at the population level while appropriately accounting for contextual differences and compositional change. Overall, I find that the field of mortality continues to be highly visible in demographic journals, including Population Studies. However much of what is published today in field journals could just as easily appear in neighbouring disciplinary journals, as disciplinary boundaries are shrinking.

The Crucial Role of Mothers and Siblings in Child Survival: Evidence From 29 Health and Demographic Surveillance Systems in Sub-Saharan Africa

A considerable body of research has studied the effects of siblings on child mortality through birth intervals. This research has commonly focused on older siblings. We argue that birth intervals with younger siblings may have equal or stronger effects on child mortality, even during a mother's pregnancy. Moreover, we contend that birth interval effects need to be considered only when siblings are coresident. Using longitudinal data from 29 Health and Demographic Surveillance Systems across sub-Saharan Africa, covering more than 560,000 children, we examine the proximate role of siblings and mothers in child mortality. We find that a birth interval of 24 months or more is advantageous for both older and younger siblings. The effect of a younger sibling on child mortality is more pronounced than that of an older sibling and adds to the effect of an older sibling. Moreover, child mortality is particularly low during a mother's subsequent pregnancy, contrasting the shock resulting from a younger sibling's birth. Further, we find that a mother's or sibling's absence from the household results in a higher risk of mortality, and the death of either reduces child survival up to six months before the death.

Effects of previous birth interval length on child outcomes can be estimated in a sibling analysis even when there are only two siblings

BACKGROUND

There is much interest in how the length of the previous birth interval affects various child outcomes, and it has become increasingly common to estimate such effects from sibling models. This is because one then controls for unobserved determinants of the outcome that are shared between the siblings and linked to the birth interval length. However, it is a common idea that such effects can only be estimated from data on families with three or more children.

OBJECTIVE

The goal of this paper is to show, through an intuitive argument and a simulation experiment, that it is possible to estimate effects of birth interval only from families with two children.

METHODS

Observations are simulated from two equations for fertility and one equation for child mortality. The fertility equations include a random term that is assumed to be correlated with the random term in the mortality equation. Mortality models are then estimated from the simulated observations. This is done 1000 times, and the averages of the 1000 sets of estimates are calculated.

RESULTS

The simulation experiment illustrates that it is indeed possible (by using a model specification that takes into account that no birth interval is defined for the first birth) to estimate birth interval effects in sibling models even when the data include only families with two children.

CONCLUSION

It is good news that families with only two children can contribute to the estimation of birth interval effects. This is because, with a broader basis for the estimation, the precision is improved and there is less reason for concern about the general relevance of the estimates. An important limitation, however, is that it is potentially problematic to control for maternal age in a sibling model estimated only for the first and second child.

Impact of high-risk fertility behaviours on underfive mortality in Asia and Africa: evidence from Demographic and Health Surveys

Background

Maternal age < 18 or > 34 years, short inter-pregnancy birth interval, and higher birth order are considered to be high-risk fertility behaviours (HRFB). Underfive mortality being disproportionately concentrated in Asia and Africa, this study analyses the association between HRFB and underfive 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 birth of index child < 18 or > 34 years, preceding birth interval < 24 months and child’s birth order > 3. Using logistic regression, we analysed change in the odds of underfive 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 birth of index child < 18 years and preceding birth interval (PBI) < 24 months were significant risk factors of underfive mortality, while a child’s birth order > 3 was a protective factor. Presence of any single HRFB was associated with 7% higher risk of underfive mortality (OR 1.07; 95% CI 1.04–1.09). Presence of multiple HRFBs was associated with 39% higher risk of underfive mortality (OR 1.39; 95% CI 1.36–1.43). Some specific combinations of HRFB such as maternal age < 18 years and preceding birth interval < 24 month significantly increased the odds of underfive mortality (OR 2.07; 95% CI 1.88–2.28).

Conclusion

Maternal age < 18 years and short preceding birth interval significantly increase the risk of underfive mortality. This highlights the need for an effective legislation to curb child marriages and increased public investment in reproductive healthcare with a focus on higher contraceptive use for optimal birth spacing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03780-y.

Linking the timing of a mother's and child's death: Comparative evidence from two rural South African population-based surveillance studies, 2000-2015

BACKGROUND

The effect of the period before a mother's death on child survival has been assessed in only a few studies. We conducted a comparative investigation of the effect of the timing of a mother's death on child survival up to age five years in rural South Africa.

METHODS

We used discrete time survival analysis on data from two HIV-endemic population surveillance sites (2000-2015) to estimate a child's risk of dying before and after their mother's death. We tested if this relationship varied between sites and by availability of antiretroviral therapy (ART). We assessed if related adults in the household altered the effect of a mother's death on child survival.

FINDINGS

3,618 children died from 2000-2015. The probability of a child dying began to increase in the 7-11 months prior to the mother's death and increased markedly in the 3 months before (2000-2003 relative risk = 22.2, 95% CI = 14.2-34.6) and 3 months following her death (2000-2003 RR = 20.1; CI = 10.3-39.4). This increased risk pattern was evident at both sites. The pattern attenuated with ART availability but remained even with availability at both sites. The father and maternal grandmother in the household lowered children's mortality risk independent of the association between timing of mother and child mortality.

CONCLUSIONS

The persistence of elevated mortality risk both before and after the mother's death for children of different ages suggests that absence of maternal care and abrupt breastfeeding cessation might be crucial risk factors. Formative research is needed to understand the circumstances for children when a mother is very ill or dies, and behavioral and other risk factors that increase both the mother and child's risk of dying. Identifying families when a mother is very ill and implementing training and support strategies for other members of the household are urgently needed to reduce preventable child mortality.

When and Where Birth Spacing Matters for Child Survival: An International Comparison Using the DHS

A large body of research has found an association between short birth intervals and the risk of infant mortality in developing countries, but recent work on other perinatal outcomes from highly developed countries has called these claims into question, arguing that previous studies have failed to adequately control for unobserved heterogeneity. Our study addresses this issue by estimating within-family models on a sample of 4.5 million births from 77 countries at various levels of development. We show that after unobserved maternal heterogeneity is controlled for, intervals shorter than 36 months substantially increase the probability of infant death. However, the importance of birth intervals as a determinant of infant mortality varies inversely with maternal education and the strength of the relationship varies regionally. Finally, we demonstrate that the mortality-reducing effects of longer birth intervals are strong at low levels of development but decline steadily toward zero at higher levels of development. These findings offer a clear way to reconcile previous research showing that birth intervals are important for perinatal outcomes in low-income countries but are much less consequential in high-income settings.