In the present study, we found that the rate of stunting and underweight in under-five children increased significantly with an increase in birth order and shorter birth interval. However, the overall result of multivariate logistic regression did not specifically show a significant relationship between the planning of birth and undernutrition. We found that younger age at marriage, poor socioeconomic characteristics of the mother, area of residence were significantly associated with childhood undernutrition.
Rate of stunting and underweight and planning of birth
The stunting rate and underweight rate of children under-five years of age in Nepal are quite similar to the national stunting rate and underweight rate in under-five years of age children of selected South Asian countries. Pakistan DHS 2017/18 reported the overall stunting rate of 37.6% and underweight rate of 23%.(28) The stunting rate and underweight rate in Bangladesh were 31% and 22%, respectively, as per Bangladesh DHS 2017/18.(29) In contrast, the prevalence rate of stunting and underweight in under-five children in the Maldives is relatively less in comparison to the prevalence rate in other South Asian countries. Maldives DHS 2016/17 reported an only national prevalence rate of 15.3% stunting and 15% underweight.(30) The continuous decline in the prevalence of childhood undernutrition in Nepal since 2001 can be attributed to the rigorous implementation of the several large-scale nutrition-specific projects and programs led by GoN, with the help of development partners.
This study showed that the prevalence of stunting and underweight increases with higher birth order and shorter birth intervals. This finding was consistent with previous studies that sought to examine the relationship between the planning of birth and childhood undernutrition. For example, a retrospective analysis of the National Family Health Survey (NFHS) 2015/16 data of India also reported the highest rate of stunting (53.1%) and underweight (48.4%) in children with birth order >3 and <3 years of IBBSB.(15) Rana et al. found a lower risk for stunting (20%; p < 0.01) and underweight (14%; p < 0.05) in the first birth order with >24 months of IBMFB in their retrospective study that analysed DHS data of selected South Asia countries (Nepal, India, Bangladesh, and Pakistan).(20) A retrospective study analyzing a large scale survey in India to investigate the relationship between birth interval and childhood undernutrition also reported a 28% increase in stunting and 26% increase in underweight for those children born with a birth interval of < 24 months.(25)
Factors associated with stunting and underweight
This study showed significantly lower odds of stunting only in children with birth order one and 12-24 months of IBMFB as compared to those children with birth order one and <12 months of IBMFB. However, the present study did not yield a significant relationship between the planning of birth and underweight. The result of a retrospective study analyzing the 2002-2003 El Salvador NFHS data to examine the relationship between birth spacing and childhood undernutrition also showed significantly higher odds of stunting in birth intervals of <24 months (OR 1.52, 95% CI 1.21-1.92) and intervals of 25-35 months (OR 1.30, 95% CI 1.05-1.64) as compared to intervals of 36-59 months.(23) As in the present study, this study also did not show a significant relationship between birth interval and underweight. The birth interval was reported as a significant predictor of child stunting in a cross-sectional study that aimed to measure the prevalence and identify the predictors of undernutrition in children age 0-59 months in Hyderabad, India by Peter et al. (OR 1.82, 95% CI 1.03-3.21).(31)
The result of the multivariate logistic regression showed that low BMI was not significantly associated with stunting in the present study, but it had significantly higher odds of underweight children as compared to mothers with normal BMI. In contrast, a cross-sectional study examining the factors associated with child stunting and underweight in 35 low-and middle-income countries showed significantly increased odds of child stunting (OR 1.6, 95% CI1.6-1.7, p<0.001) in mothers with low BMI.(32) The significant association was also observed for underweight (OR 2.3, 95% CI 2.1-2.4, p<0.001).(32) Nahar et al., in their case-control study, also reported that severely underweight children were more likely to have underweight mothers (AOR 3.8, 95% CI 2.6-5.4).(33) A cross-sectional study conducted in ten slums of Hyderabad, India, to appraise caregiving practices and health and nutritional status of children under-five reported low BMI of mother to be the significant predictor of stunting (OR 1.99, 95% CI 1.5-4.7).(31) Another retrospective study by Yang et al. reported significantly decreased odds of stunting for obese mothers (OR 0.70, 95% CI 0.61-0.79, p≤0.001), which was consistent to the outcome of the present study (OR 0.6, 95% CI 0.4-0.9, p<0.05).(34)
Mother's in the age group 20-24 years had a significantly lower odds of stunting as compared to mothers in the age group 15-19 years in the present study. Another case-control study in Bangladesh that investigated the risk factors associated with severe underweight among young children aged 6-24 months also reported the mother's age <19 years as a strong risk factor to cause child underweight (AOR 3.0, 95% CI 1.9-4.8).(33) In contrast, Yang et al. reported significantly higher odds of stunting in the age group 20-30 (OR 1.18, 95% CI 1.08-1.29, p<0.001).(34)
We obtained significantly lower odds of stunting as well as underweight in poorer, middle, richer, and the richest wealth quintile in comparison to those who were in the poorest wealth quintile. Li et al. also reported that the poorest household wealth was the strongest factor associated with both child stunting (OR 1.7, 95% CI 1.6-1.8, p<0.001) and underweight (OR 1.2, 95% CI 1.1-1.3, p<0.001).(32) A retrospective study analyzing Uganda DHS to examine determinants of stunting in under-five children reported similar higher odds of stunting in the poorest wealth quintile (OR 1.73, 95% CI1.45-2.06, p≤0.001).(34) Another retrospective study analyzing NDHS data also reported higher odds of stunting among babies born to poorer families than those born to wealthier families (AOR 1.51, 95% CI 1.23-1.87).(35)
The present study showed that children > 11 months are a strong predictor of stunting and underweight. A community-based cross-sectional study that examined factors associated with underweight among under-five children in Eastern Nepal reported that children who were > 24 months of age were more likely to be underweight than children <24 months (OR 2.72, 95% CI 1.6-4.7).(36)
To our knowledge, this is one of the few studies in Nepal to examine the relationship between PoB and childhood undernutrition. However, this study has a few known limitations. We used data of the NDHS 2016 cross-sectional survey, but a causal relationship between the associated factors and outcome cannot be inferred from this study. There is a possibility of residual confounding.