One in 14 births to young mothers in Bangladesh, India, Nepal, and Pakistan ends with the death of a child within the first year [1]. Recent analysis of nationally representative data from these nations documents that young maternal age at birth and short interpregnancy interval are significant drivers of infant death among births to young mothers. The aim of the present study was to quantify the proportion of infant deaths attributable to these factors.
Using the most recent nationally representative Demographic and Health Survey (DHS) data [2], nation-specific logistic regression analyses were conducted to assess associations of younger maternal age at birth (<18 years vs ≥18 years) and preceding interpregnancy interval (<24 months vs ≥24 months or firstborn) with infant mortality among births to 15-24 year olds. Based on multivariate regression models, the percent of infant deaths attributable to each independent variable of interest was quantified using the population attributable fraction [3]. Population attributable fractions were then applied to 2012 population estimates [4] and age-specific fertility rates [2] to produce an estimate of the number of infant deaths attributable to the factors of interest. Local institutional review board approvals were obtained for DHS data collection, and institutional review board approval was obtained from the University of California, San Diego, USA, for the present analyses.
The findings demonstrate that both young maternal age and short interpregnancy interval significantly increase the risk for infant mortality in India and Pakistan, contributing to 23%-26% (>200 000 in 2012) of infant deaths to young mothers in those nations (Table 1). In Bangladesh, only short interpregnancy interval was linked to infant mortality, accounting for 7% of infant deaths to young mothers. In Nepal, young motherhood but not short interpregnancy interval was associated with infant death.
Table 1. Associations of young maternal age at birth and short interpregnancy intervals with infant deaths among births to young mothers a.
| Adjusted odds ratio b (95% confidence interval) | Population attributable fraction b (95% confidence interval), % | Estimated attributable infant deaths c (95% confidence interval) | |
|---|---|---|---|
| Bangladesh, 2011 (n=6023) | |||
| Mother's age at birth, y | |||
| ≥18 | [REF] | ||
| <18 | 1.07 (0.80–1.42) | 3 (−12 to 16) | 2981 (−11 345 to 15 406) |
| Interpregnancy interval, mo | |||
| ≥24/firstborn | [REF] | ||
| <24 | 2.27 (1.40–3.68) | 7 (2–11) | 6367 (2066–10 472) |
| India, 2005–2006 (n=23 989) | |||
| Mother's age at birth, y | |||
| ≥18 | [REF] | ||
| <18 | 1.39 (1.20-1.60) | 11 (6-15) | 69 815 (38 253-99 731) |
| Interpregnancy interval, mo | |||
| ≥24/firstborn | [REF] | ||
| <24 | 2.56 (2.06–318) | 15 (11–18) | 94 082 (71 675–115 612) |
| Nepal, 2011 (n=2560) | |||
| Mother's age at birth, y | |||
| ≥18 | [REF] | ||
| <18 | 1.62 (103–2.56) | 16 (−1 to 30) | 3779 (−325 to 7200) |
| Interpregnancy interval, mo | |||
| ≥24/firstborn | [REF] | ||
| <24 | 1.43 (0.67–3.05) | 3 (−5 to 11) | 853 (−1102 to 2657) |
| Pakistan, 2007 (n=2630) | |||
| Mother's age at birth, y | |||
| ≥18 | [REF] | ||
| <18 | 1.59 (1.20–2.11) | 12 (4–20) | 23 078 (7842–37 031) |
| Interpregnancy interval, mo | |||
| ≥24/firstborn | [REF] | ||
| <24 | 1.83 (1.23–2.71) | 11 (3–18) | 20 527 (6427–33 537) |
15-24 years of age.
Adjusted for variables in table as well as rural residence, education, household wealth quintile, and birth order.
The results highlight the importance of delayed marriage and improved contraceptive use among young people as a means of reducing infant mortality rates in South Asia. Although both of the studied factors were not consistently associated with infant deaths across nations, child marriage, young motherhood, and low contraceptive use among adolescent wives are concerns in all of the nations assessed [2]. Nonetheless, India and Pakistan require the greatest focus on these issues.
The present findings could, in part, be attributed to the use of older data in India and Pakistan relative to Bangladesh and Nepal; however, India and Pakistan are not on track to achieve Millennium Development Goal 4: the reduction of under-5 mortality by two-thirds between 1990 and 2015. Inadequate progress on contraceptive use and delaying marriage may be impeding this achievement for these nations. Analysis of more recent data, when available, is needed to confirm the study findings.
Synopsis.
In India and Pakistan, but not Bangladesh or Nepal, young maternal age and short interpregnancy interval contribute to more than 20% of infant deaths (200 000 in 2012).
Acknowledgments
The present work was funded by grants from the David and Lucile Packard Foundation (No. 2011-37366) and the National Institutes of Health (No. R01HD061115).
Footnotes
Conflict of interest: The authors have no conflicts of interest.
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References
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