Residual confounding explains the association between high parity and child mortality

Incidence and predictors of under-five mortality in East Africa using multilevel Weibull regression modeling

BACKGROUND

In 2017, an estimated 5.3 million under-five children died annually in Sub-Saharan African countries, more than half of those deaths occurred in East Africa. Though East African countries share the huge burden of global under-five mortality, there is limited evidence on the incidence and predictors of under-five mortality. Therefore, this study investigated the incidence and predictors of under-five mortality in East Africa.

METHODS

A community-based cross-sectional study was done based on the Demographic and Health Survey (DHS) data of 12 East African countries conducted from 2008 to 2019. A total weighted sample of 138,803 live births within 5 years preceding the survey were included for analysis. The Kaplan-Meier curve and Log-rank test were done to assess the children's survival experience across variable categories. The Global Schoenfeld residual test was employed for checking Proportional Hazard (PH) assumptions and it was violated (p-value< 0.05). Considering the hierarchical nature of DHS data, multilevel parametric survival models were fitted. Model comparison was made by AIC, deviance, and shape of the hazard function. Variables with a p-value of less than 0.2 in the bi-variable analysis were considered for the multivariable analysis. In the multilevel Weibull regression analysis, the Adjusted Hazard Ratio (AHR) with 95% Confidence Interval (CI) was reported to declare the significant predictors of under-five mortality.

RESULTS

Under-five mortality rate in East Africa was 51.318 (95% CI: 51.311, 51.323) per 1000 live births. Babies born to mothers attained secondary education and above (AHR = 0.83, 95% CI: 0.75, 0.91), being 2nd - 4th birth order (AHR = 0.62, 95% CI: 0.56, 0.67), ≥ 5th birth order (AHR = 0.68, 95% CI: 0.61, 0.76), health facility delivery (AHR = 0.87, 95% CI: 0.82, 0.93), 1-3 ANC visit (AHR = 0.61, 95% CI: 0.54, 0.68), births interval of 24-48 months (AHR = 0.53, 95% CI: 0.50, 0.57), wanted pregnancy (AHR = 0.72, 95% CI: 0.68, 0.76), middle wealth status (AHR = 0.90, 95% CI: 0.83, 0.97), and richest wealth status (AHR = 0.81, 95% CI:0.73, 0.90) were significantly associated with lower hazards of under-five mortality. Whereas, advanced maternal age (≥35 years) (AHR = 1.13, 95% CI: 1.04, 1.24),, babies born to household who did not have media exposure (AHR = 1.13, 95% CI: 1.07, 1.20), twin births (AHR = 3.81, 95% CI: 3.52, 4.12), being male child (AHR = 1.27, 95%CI: 1.21, 1.33), small birth size at birth (AHR = 1.73, 95% CI: 1.63, 1.84), and large size at birth (AHR = 1.11, 95% CI: 1.04, 1.11) were significantly associated with higher hazards of under-five mortality.

CONCLUSION

Under-five mortality is a major public health concern in East African countries. Health facility delivery, ANC visit, higher wealth status, adequate birth spacing, wanted pregnancy, and maternal education were significantly correlated with a lower risk of under-5 mortality. Whereas, higher birth order, small or large size at birth, male birth, twin birth, advanced maternal age and mothers who didn't have media exposure were significantly correlated with a higher risk of under-five mortality. This study highlights that public health programs should enhance health facility delivery, ANC visit, media exposure, maternal education, and adequate birth spacing to decrease the incidence of under-five mortality in East Africa.

"Children are a blessing from God" - a qualitative study exploring the socio-cultural factors influencing contraceptive use in two Muslim communities in Kenya

Background

Family planning (FP) is one of the high impact public health interventions with huge potential to enhance the health and wellbeing of women and children. Yet, despite the steady progress made towards expanding access to family planning, major disparities across different regions exist in Kenya. This study explored the socio cultural factors influencing FP use among two Muslim communities in Kenya.

Methods

A qualitative study involving Focus Group Discussions (FGDs) and In-depth Interviews (IDIs) was conducted (from July to October 2018) in two predominant Muslim communities of Lamu and Wajir counties. Open ended questions explore key thematic areas around knowledge, attitudes and understanding of contraception, perceived FP barriers, and decision making for contraceptives, views on Islam and contraception, and fertility preference. All interviews were conducted in the local language, recorded, transcribed verbatim and translated into English. Data was analyzed using thematic content analyses.

Results

Although Islam is the predominant religion the two communities, perceptions and belief around FP use were varied. There were differing interpretations of Islamic teaching and counter arguments on whether or not Islam allows FP use. This, in addition to desire for a large family, polygamy, high child mortality and a cultural preference for boys had a negative impact on FP use. Similarly, inability of women to make decisions on their reproductive health was a factor influencing uptake of FP.

Conclusion

Misinterpretation of Islamic teaching on contraception likely influences uptake of family planning. Cultural beliefs and lack of women’s decision power on fertility preferences were a key inhibitor to FP use. Countering the negative notions of FP use requires active engagement of religious leaders and Muslim scholars who are in position of power and influence at community level.

Maternal grand multiparity and intention to use modern contraceptives in Nigeria

BACKGROUND

Grand multiparity and low contraceptive prevalence are dominant among Nigerian women. These elevate the risk of unintended pregnancies, high-risk fertility and adverse maternal and child health outcomes among women in the country, particularly grand multiparous women. Studies have examined predictors of intention to use modern contraceptives among women of reproductive age. However, these studies did not ascertain the extent to which grand multiparity is associated with intention to use modern contraceptives. This study examined association between grand multiparity and intention to use modern contraceptives in Nigeria.

METHODS

The study pooled data from 2003 to 2013 Nigeria Demographic and Health Surveys. The weighted sample size analysed was 34,302 women. The outcome variable was intention to use contraceptive. The main explanatory variable was parity with specific attention to grand multiparity. Unadjusted multinomial logistic regression coefficients were used to examine association between specific explanatory or control variables and intention to use contraceptives while the adjusted multinomial logistic regression was applied to further examine associated factors of intention to use contraceptives relative to being uncertain about future contraceptive use. Four multinomial logistic regression models were fitted using Stata 14.

RESULTS

More than half of respondents do not intend to use contraceptives, while less than one-fifth of respondents intend to use contraceptives in the future. Across the four fitted models, the relative risks of intention to use compared with being uncertain about future contraceptive use were significantly lower among grand multiparous women. Results further revealed pregnancy termination, fertility planning status, exposure to mass media family planning messages, knowledge of modern contraceptives, ideal family size, remarriage, household power relations, and maternal education as other key factors influencing expected risk of intention to use contraceptives relative to being uncertain about future contraceptive use.

CONCLUSION

Maternal grand multiparity is significantly associated with intention to use contraceptives among women in Nigeria. The development of a specific population and health programme to target grand multiparous women is imperative in the country. Such programme could be integrated into existing national family planning programme through specific contraceptive education, counselling and information for high parous women.

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

There is still considerable uncertainty about how reproductive factors affect child mortality. This study, based on Demographic and Health Survey data from 28 countries in sub-Saharan Africa, shows that mortality is highest for firstborn children with very young mothers. Other children with young mothers, or of high birth order, also experience high mortality. Net of maternal age and birth order, a short preceding birth interval is associated with above average mortality. These patterns change, however, if time-invariant unobserved mother-level characteristics of importance for both mortality and fertility are controlled for in a multilevel-multiprocess model. Most importantly, there are smaller advantages associated with longer birth intervals and being older at first birth. The implications of alternative reproductive 'strategies' are discussed, taking into account that if the mother is older at birth, the child will also be born in a later calendar year, when mortality may be lower.

The effects of family planning and other factors on fertility, abortion, miscarriage, and stillbirths in the Spectrum model

BACKGROUND

The Lives Saved Tool (LiST) estimates the effects of maternal and child health interventions on mortality rates and the number of deaths. The family planning module in Spectrum interacts with LiST by providing estimates of the effects of scaling up family planning use on the number of live births, miscarriages, abortions, and stillbirths.

METHODS

We use the proximate determinants of fertility framework to estimate the effects of changes in contraceptive use, proportion married, postpartum insusceptibility, abortion and sterility on the total fertility rate. We extend this framework to estimate the number of intended and unintended pregnancies and the resulting live births, abortions, stillbirths, and miscarriages.

RESULTS

We apply the model to four countries (Mali, Kenya, Indonesia, and Ukraine) to demonstrate possible trends with a range of family planning and fertility levels. In high-fertility countries, such as Mali, increases in contraceptive use will partially compensate for the increasing number of women of reproductive age to reduce the annual increases in pregnancies and births. Most unintended pregnancies occur to women defined as having unmet need for contraception. In low-fertility countries, increases in contraceptive use may reduce abortion rates and low levels of unmet need mean that most unintended pregnancies are due to method failure.

CONCLUSIONS

The family planning module in Spectrum provides a useful framework to incorporate changes in contraceptive practices and pregnancy outcomes in the LiST calculations of mortality rates and deaths.

Association between Birth Interval and Cardiovascular Outcomes at 30 Years of Age: A Prospective Cohort Study from Brazil

Background

Birth interval is an important and potentially modifiable factor that is associated with child health. Whether an association exists with longer-term outcomes in adults is less well known.

Methods

Using the 1982 Pelotas (Brazil) Birth Cohort Study, the association of birth interval with markers of cardiovascular health at 30 years of age was examined. Multivariable linear regression was used with birth interval as a continuous variable and categorical variable, and effect modification by gender was explored.

Results

Birth interval and cardiovascular data were present for 2,239 individuals. With birth interval as a continuous variable, no association was found but stratification by gender tended to show stronger associations for girls. When compared to birth intervals of <18 months, as binary variable, longer intervals were associated with increases in height (1.6 cm; 95% CI: 0.5, 2.8) and lean mass (1.7 kg; 95% CI: 0.2, 3.2). No difference was seen with other cardiovascular outcomes.

Conclusions

An association was generally not found between birth interval and cardiovascular outcomes at 30 years of age, though some evidence existed for differences between males and females and for an association with height and lean mass for birth intervals of 18 months and longer.

Disparities in Infant Mortality Due to Congenital Anomalies on Guam

In the 1970's and 1980's, there were large inter-village disparities in infant mortality due to congenital anomalies on Guam. A village-level analysis was conducted to determine if these disparities can be explained by behavioral (ie, median age of village females, village fertility ratio), structural (ie, population density, persons per household, single mother households per village, married females per village), and environmental (ie, living in a village where Agent Orange (AO) spraying was conducted) factors. Village-level data for live births and infant mortality due to congenital anomalies (1970-1989) was collected from Guam's Office of Vital Statistics. Data on median age of village females, village fertility ratio, population density, persons per household, single mother households, and married females were obtained from the 1980 US Census. Estimates of village-level AO use were provided through personal communications, and villages were dichotomized into AO and non-AO spray areas. Village location was classified by usual residence of the mother. Linear regression was used to determine associations between infant mortality due to congenital anomalies and the behavioral, structural, and environmental factors. The association between AO spray area and infant mortality due to congenital anomalies was statistically significant under univariable (B [95%CI] = 1.88 [0.64,3.11], P = .005) and multivariable conditions (B [95%CI] = 2.02 [0.08,3.96], P = .042). These results suggest that infants born to mothers whose usual residence was in an AO spray area on Guam are at an increased risk of mortality due to congenital anomalies. Further studies using individual-level data are needed to validate these results.

Potential confounding in the association between short birth intervals and increased neonatal, infant, and child mortality

BACKGROUND

Recent steep declines in child mortality have been attributed in part to increased use of contraceptives and the resulting change in fertility behaviour, including an increase in the time between births. Previous observational studies have documented strong associations between short birth spacing and an increase in the risk of neonatal, infant, and under-five mortality, compared to births with longer preceding birth intervals. In this analysis, we compare two methods to estimate the association between short birth intervals and mortality risk to better inform modelling efforts linking family planning and mortality in children.

OBJECTIVES

Our goal was to estimate the mortality risk for neonates, infants, and young children by preceding birth space using household survey data, controlling for mother-level factors and to compare the results to those from previous analyses with survey data.

DESIGN

We assessed the potential for confounding when estimating the relative mortality risk by preceding birth interval and estimated mortality risk by birth interval in four categories: less than 18 months, 18-23 months, 24-35 months, and 36 months or longer. We estimated the relative risks among women who were 35 and older at the time of the survey with two methods: in a Cox proportional hazards regression adjusting for potential confounders and also by stratifying Cox regression by mother, to control for all factors that remain constant over a woman's childbearing years. We estimated the overall effects for birth spacing in a meta-analysis with random survey effects.

RESULTS

We identified several factors known for their associations with neonatal, infant, and child mortality that are also associated with preceding birth interval. When estimating the effect of birth spacing on mortality, we found that regression adjustment for these factors does not substantially change the risk ratio for short birth intervals compared to an unadjusted mortality ratio. For birth intervals less than 18 months, standard regression adjustment for confounding factors estimated a risk ratio for neonatal mortality of 2.28 (95% confidence interval: 2.18-2.37). This same effect estimated within mother is 1.57 (95% confidence interval: 1.52-1.63), a decline of almost one-third in the effect on neonatal mortality.

CONCLUSIONS

Neonatal, infant, and child mortality are strongly and significantly related to preceding birth interval, where births within a short interval of time after the previous birth have increased mortality. Previous analyses have demonstrated this relationship on average across all births; however, women who have short spaces between births are different from women with long spaces. Among women 35 years and older where a comparison of birth spaces within mother is possible, we find a much reduced although still significant effect of short birth spaces on child mortality.

Exploring the association between short/long preceding birth intervals and child mortality: using reference birth interval children of the same mother as comparison

Background

This study used data from recent Demographic and Health Surveys (DHS) to examine the impact of short or long preceding birth intervals on neonatal and under-five mortality. In order to minimize the effect of selection issues, we examined child mortality outcomes of the same mother, comparing short or long interval births against births with what had previously been considered optimal intervals.

Methods

We analyzed 47 DHS datasets from low- and middle-income countries. For each dataset, we compared neonatal and under-five mortality of short preceding interval births (<18 months, <24 months) to reference interval births (24-<60 months) of a mother, using conditional logistic regression matching on the mother. We also conducted the same matched analysis for long (≥60 months, ≥72 months) preceding interval births. These associations were then meta-analyzed. We also stratified the analyses by mothers’ completed fertility (fertility at end of reproductive period) to assess whether maternal characteristics highly correlated with completed fertility modify the association between birth interval and child mortality.

Results

Children with shorter preceding intervals had increased odds of both neonatal (<24 months, OR: 1.61, 95% CI: 1.52-1.70) and under-five mortality (<24 months, OR: 1.48, 95% CI: 1.40-1.56). When the associations were stratified by the mothers’ completed fertility, the impact of short intervals was greatly reduced or eliminated for low fertility mothers. In contrast, mortality associations became stronger for children of high fertility mothers. However, when the births of high fertility mothers were limited to birth orders 2-4, the associations were comparable to those of low fertility mothers. Longer preceding birth intervals had lower odds of mortality than reference intervals (i.e. under-5 mortality for ≥60 months, OR 0.59, 95% CI: 0.52-0.67). This effect was also mediated by mothers’ completed fertility; there was a strong protective effect of longer birth intervals for the high fertility mothers but not for low fertility mothers.

Conclusions

These analyses reproduced findings reported in previous literature that shorter birth intervals are associated with higher child mortality. However the negative impact of short birth intervals may only occur in high parity births. Reproductive health interventions that seek to lengthen birth intervals may have larger impact by targeting women with high parity. This finding is consistent with the concept of maternal depletion as the underlying cause of increased adverse child outcomes associated with shorter birth intervals.

The associations of birth intervals with small-for-gestational-age, preterm, and neonatal and infant mortality: a meta-analysis

Background

Short and long birth intervals have previously been linked to adverse neonatal outcomes. However, much of the existing literature uses cross-sectional studies, from which deriving causal inference is complex. We examine the association between short/long birth intervals and adverse neonatal outcomes by calculating and meta-analyzing associations using original data from cohort studies conducted in low-and middle-income countries (LMIC).

Methods

We identified five cohort studies. Adjusted odds ratios (aOR) were calculated for each study, with birth interval as the exposure and small-for-gestational-age (SGA) and/or preterm birth, and neonatal and infant mortality as outcomes. The associations were controlled for potential confounders and meta-analyzed.

Results

Birth interval of shorter than 18 months had statistically significant increased odds of SGA (pooled aOR: 1.51, 95% CI: 1.31-1.75), preterm (pooled aOR: 1.58, 95% CI: 1.19-2.10) and infant mortality (pooled aOR: 1.83, 95% CI: 1.19-2.81) after controlling for potential confounding factors (reference 36-<60 months). It was also significantly associated with term-SGA, preterm-appropriate-for-gestational-age, and preterm-SGA. Birth interval over 60 months had increased risk of SGA (pooled aOR: 1.22, 95% CI: 1.07-1.39) and term-SGA (pooled aOR: 1.14, 95% CI: 1.03-1.27), but was not associated with other outcomes.

Conclusions

Birth intervals shorter than 18 months are significantly associated with SGA, preterm birth and death in the first year of life. Lack of access to family planning interventions thus contributes to the burden of adverse birth outcomes and infant mortality in LMICs. Programs and policies must assess ways to provide equitable access to reproductive health interventions to mothers before or soon after delivering a child, but also address underlying socioeconomic factors that may modify and worsen the effect of short intervals.

The associations of parity and maternal age with small-for-gestational-age, preterm, and neonatal and infant mortality: a meta-analysis

Background

Previous studies have reported on adverse neonatal outcomes associated with parity and maternal age. Many of these studies have relied on cross-sectional data, from which drawing causal inference is complex. We explore the associations between parity/maternal age and adverse neonatal outcomes using data from cohort studies conducted in low- and middle-income countries (LMIC).

Methods

Data from 14 cohort studies were included. Parity (nulliparous, parity 1-2, parity ≥3) and maternal age (<18 years, 18-<35 years, ≥35 years) categories were matched with each other to create exposure categories, with those who are parity 1-2 and age 18-<35 years as the reference. Outcomes included small-for-gestational-age (SGA), preterm, neonatal and infant mortality. Adjusted odds ratios (aOR) were calculated per study and meta-analyzed.

Results

Nulliparous, age <18 year women, compared with women who were parity 1-2 and age 18-<35 years had the highest odds of SGA (pooled adjusted OR: 1.80), preterm (pooled aOR: 1.52), neonatal mortality (pooled aOR: 2.07), and infant mortality (pooled aOR: 1.49). Increased odds were also noted for SGA and neonatal mortality for nulliparous/age 18-<35 years, preterm, neonatal, and infant mortality for parity ≥3/age 18-<35 years, and preterm and neonatal mortality for parity ≥3/≥35 years.

Conclusions

Nulliparous women <18 years of age have the highest odds of adverse neonatal outcomes. Family planning has traditionally been the least successful in addressing young age as a risk factor; a renewed focus must be placed on finding effective interventions that delay age at first birth. Higher odds of adverse outcomes are also seen among parity ≥3 / age ≥35 mothers, suggesting that reproductive health interventions need to address the entirety of a woman’s reproductive period.

Funding

Funding was provided by the Bill & Melinda Gates Foundation (810-2054) by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group.