Relative importance of prenatal and postnatal determinants of stunting: data mining approaches to the MINIMat cohort, Bangladesh.

INTRODUCTION: WHO has set a goal to reduce the prevalence of stunted child growth by 40% by the year 2025. To reach this goal, it is imperative to establish the relative importance of risk factors for stunting to deliver appropriate interventions. Currently, most interventions take place in late infancy and early childhood. This study aimed to identify the most critical prenatal and postnatal determinants of linear growth 0-24 months and the risk factors for stunting at 2 years, and to identify subgroups with different growth trajectories and levels of stunting at 2 years. METHODS: Conditional inference tree-based methods were applied to the extensive Maternal and Infant Nutrition Interventions in Matlab trial database with 309 variables of 2723 children, their parents and living conditions, including socioeconomic, nutritional and other biological characteristics of the parents; maternal exposure to violence; household food security; breast and complementary feeding; and measurements of morbidity of the mothers during pregnancy and repeatedly of their children up to 24 months of age. Child anthropometry was measured monthly from birth to 12 months, thereafter quarterly to 24 months. RESULTS: Birth length and weight were the most critical factors for linear growth 0-24 months and stunting at 2 years, followed by maternal anthropometry and parental education. Conditions after birth, such as feeding practices and morbidity, were less strongly associated with linear growth trajectories and stunting at 2 years. CONCLUSION: The results of this study emphasise the benefit of interventions before conception and during pregnancy to reach a substantial reduction in stunting

Early Life Environmental Exposure to Cadmium, Lead, and Arsenic and Age at Menarche: A Longitudinal Mother-Child Cohort Study in Bangladesh

BACKGROUND: Several metals act as endocrine disruptors, but there are few large longitudinal studies about associations with puberty onset. OBJECTIVES: We evaluated whether early life cadmium, lead, and arsenic exposure was associated with timing of menarche. METHODS: In a mother-child cohort in rural Bangladesh (n=935), the exposure was assessed by concentrations in maternal erythrocytes in early pregnancy and in girls' urine at 5 and 10 years of age using inductively coupled plasma mass spectrometry. The girls were interviewed twice, at average ages 13.3 [standard deviation (SD)=0.43] and 13.8 (SD=0.43) y, and the date of menarche, if present, was recorded. Associations were assessed using Kaplan-Meier analysis and multivariable-adjusted Cox regression. RESULTS: In total, 77% of the girls (n=717) had reached menarche by the second follow-up. The median age of menarche among all girls was 13.0 y (25th-75th percentiles: 12.4-13.7 y). At 10 years of age, median urinary cadmium was 0.25μg/L (5th-95th percentiles: 0.087-0.72μg/L), lead 1.6μg/L (0.70-4.2μg/L), and arsenic 54μg/L (19-395μg/L). Given the same age, girls in the highest quartile of urinary cadmium at 5 and 10 years of age had a lower rate of menarche than girls in the lowest quartile, with an adjusted hazard ratio of (HR) 0.80 (95% CI: 0.62, 1.01) at 5 years of age, and 0.77 (95% CI: 0.60, 0.98) at 10 years of age. This implies that girls in the highest cadmium exposure quartile during childhood had a higher age at menarche. Comparing girls in the highest to the lowest quartile of urinary lead at 10 years of age, the former had a higher rate of menarche [adjusted HR = 1.23 (95% CI: 0.97, 1.56)], implying lower age at menarche, whereas there was no association with urinary lead at 5 years of age. Girls born to mothers in the highest quartile of erythrocyte arsenic during pregnancy were less likely to have attained menarche than girls born to mothers in the lowest quartile [adjusted HR= 0.79 (95% CI: 0.62, 0.99)]. No association was found with girls' urinary arsenic exposure. DISCUSSION: Long-term childhood cadmium exposure was associated with later menarche, whereas the associations with child lead exposure were inconclusive. Maternal exposure to arsenic, but not cadmium or lead, was associated with later menarche. https://doi.org/10.1289/EHP11121

Time trends and sociodemographic determinants of preterm births in pregnancy cohorts in Matlab, Bangladesh, 1990-2014.

INTRODUCTION: Preterm birth is the major cause of under-five mortality. Population-based data on determinants and proportions of children born preterm are limited, especially from low-income countries. This study aimed at assessing time trends and social, reproductive and environmental determinants of preterm births based on a population-based pregnancy cohort over 25 years in rural Bangladesh. METHODS: In this cohort study in Matlab, a rural area in Bangladesh, we used data from the Health and Demographic Surveillance System from 1990 to 2014. Gestational age at birth was based on the reported last menstrual period and verified by ultrasound assessments. Preterm birth proportions were assessed within strata of social and reproductive characteristics, and time series analysis was performed with decomposition for trend and seasonality. We also determined the prevented fractions of preterm birth reduction associated with social and demographic changes during the follow-up period. RESULTS: Analyses were based on 63 063 live births. Preterm birth decreased from 29% (95% CI 28.6 to 30.1) in 1990-1994 to 11% (95% CI 10.5 to 11.6) in 2010-2014. Low education, older age and multi-parity were associated with higher proportions of preterm births across the study period. Preterm births had a marked seasonal variation. A rapid increase in women's educational level and decrease in parity were associated with the decline in preterm births, and 27% of the reduction observed from 1990 to 2014 could be attributed to these educational and reproductive changes. CONCLUSION: The reduction in preterm birth was to a large extent associated with the sociodemographic transition, especially changes in maternal education and parity. The persistent seasonal variation in the proportion of preterm birth may reflect the environmental stressors for pregnant women across the study period. Continued investments in girls' education and family planning programmes may contribute to further reduction of preterm births in Bangladesh

Stunted growth in children from fetal life to adolescence : Risk factors, consequences and entry points for prevention - Cohort studies in rural Bangladesh

Stunted growth affects one in four children under the age of five years and comes with great costs for the child and society. With an increased understanding of the long-term consequences of chronic undernutrition the reduction of stunted growth has become an important priority on the global health agenda. WHO has adopted a resolution to reduce stunting by 40% by the year 2025 and to reduce stunting is one of the targets under the Sustainable Development Goals. The aim of this thesis was to study linear growth trajectories, risk factors and consequences of stunting and recovery of stunting from fetal life to adolescence in a rural Bangladeshi setting and to assess the cost-effectiveness of a prenatal nutrition intervention for under-five survival and stunting. A birth cohort of children of women participating in the Maternal and Infant Nutrition Interventions trial (MINIMat), a randomized prenatal food and multiple micronutrient (MMS) trial, was followed from birth to adolescence. Information about socioeconomic and nutritional characteristics of the mother and father was collected, and frequent anthropometry assessments of the child were done at birth, in infancy, and during childhood and adolescence. At puberty, pubertal stages according to Tanner, age at menarche and start of the pubertal growth spurt in boys were assessed. Calculations were made regarding the cost-effectiveness of prenatal food and micronutrient intervention related to the disability adjusted life years (DALYs) lost by death and stunting. At birth, the children were on average short compared the WHO growth reference and more than half of the children were Small-for-Gestational-Age. Linear growth faltered dramatically up to 2 years, after which height-for-age Z-score increased up to adolescence. The prevalence of stunting was highest at 2 years (50%) and thereafter decreasing to 25% in adolescence. Birth size, maternal anthropometry and parental education were the most influential factors for linear growth up to and stunting at 2 years. Conditions after birth, such as feeding practices and morbidity, were less important. At 10 years, children born to short mothers (<147.5 cm), mothers with no education, or those conceived in the pre-monsoon season had an increased probability to be stunted. The median age at menarche was 13.0 years. Children that were stunted in infancy and childhood had later pubertal development as compared to non-stunted children. Children that recovered from stunting had a similar timing of puberty as their peers who had never been stunted. Supplementation with combined early prenatal food and multiple micronutrients was highly cost-effective in averting DALYs from under-five deaths and stunting. The results from this thesis support the conclusion that a lifecycle approach is needed for the prevention of stunting. The gaps between current knowledge, policy and practice needs to be closed, with more emphasis given to prenatal interventions

Stunted growth in children from fetal life to adolescence : Risk factors, consequences and entry points for prevention - Cohort studies in rural Bangladesh

Stunted growth affects one in four children under the age of five years and comes with great costs for the child and society. With an increased understanding of the long-term consequences of chronic undernutrition the reduction of stunted growth has become an important priority on the global health agenda. WHO has adopted a resolution to reduce stunting by 40% by the year 2025 and to reduce stunting is one of the targets under the Sustainable Development Goals. The aim of this thesis was to study linear growth trajectories, risk factors and consequences of stunting and recovery of stunting from fetal life to adolescence in a rural Bangladeshi setting and to assess the cost-effectiveness of a prenatal nutrition intervention for under-five survival and stunting. A birth cohort of children of women participating in the Maternal and Infant Nutrition Interventions trial (MINIMat), a randomized prenatal food and multiple micronutrient (MMS) trial, was followed from birth to adolescence. Information about socioeconomic and nutritional characteristics of the mother and father was collected, and frequent anthropometry assessments of the child were done at birth, in infancy, and during childhood and adolescence. At puberty, pubertal stages according to Tanner, age at menarche and start of the pubertal growth spurt in boys were assessed. Calculations were made regarding the cost-effectiveness of prenatal food and micronutrient intervention related to the disability adjusted life years (DALYs) lost by death and stunting. At birth, the children were on average short compared the WHO growth reference and more than half of the children were Small-for-Gestational-Age. Linear growth faltered dramatically up to 2 years, after which height-for-age Z-score increased up to adolescence. The prevalence of stunting was highest at 2 years (50%) and thereafter decreasing to 25% in adolescence. Birth size, maternal anthropometry and parental education were the most influential factors for linear growth up to and stunting at 2 years. Conditions after birth, such as feeding practices and morbidity, were less important. At 10 years, children born to short mothers (<147.5 cm), mothers with no education, or those conceived in the pre-monsoon season had an increased probability to be stunted. The median age at menarche was 13.0 years. Children that were stunted in infancy and childhood had later pubertal development as compared to non-stunted children. Children that recovered from stunting had a similar timing of puberty as their peers who had never been stunted. Supplementation with combined early prenatal food and multiple micronutrients was highly cost-effective in averting DALYs from under-five deaths and stunting. The results from this thesis support the conclusion that a lifecycle approach is needed for the prevention of stunting. The gaps between current knowledge, policy and practice needs to be closed, with more emphasis given to prenatal interventions

Stunted growth in children from fetal life to adolescence : Risk factors, consequences and entry points for prevention - Cohort studies in rural Bangladesh

Stunted growth affects one in four children under the age of five years and comes with great costs for the child and society. With an increased understanding of the long-term consequences of chronic undernutrition the reduction of stunted growth has become an important priority on the global health agenda. WHO has adopted a resolution to reduce stunting by 40% by the year 2025 and to reduce stunting is one of the targets under the Sustainable Development Goals. The aim of this thesis was to study linear growth trajectories, risk factors and consequences of stunting and recovery of stunting from fetal life to adolescence in a rural Bangladeshi setting and to assess the cost-effectiveness of a prenatal nutrition intervention for under-five survival and stunting. A birth cohort of children of women participating in the Maternal and Infant Nutrition Interventions trial (MINIMat), a randomized prenatal food and multiple micronutrient (MMS) trial, was followed from birth to adolescence. Information about socioeconomic and nutritional characteristics of the mother and father was collected, and frequent anthropometry assessments of the child were done at birth, in infancy, and during childhood and adolescence. At puberty, pubertal stages according to Tanner, age at menarche and start of the pubertal growth spurt in boys were assessed. Calculations were made regarding the cost-effectiveness of prenatal food and micronutrient intervention related to the disability adjusted life years (DALYs) lost by death and stunting. At birth, the children were on average short compared the WHO growth reference and more than half of the children were Small-for-Gestational-Age. Linear growth faltered dramatically up to 2 years, after which height-for-age Z-score increased up to adolescence. The prevalence of stunting was highest at 2 years (50%) and thereafter decreasing to 25% in adolescence. Birth size, maternal anthropometry and parental education were the most influential factors for linear growth up to and stunting at 2 years. Conditions after birth, such as feeding practices and morbidity, were less important. At 10 years, children born to short mothers (<147.5 cm), mothers with no education, or those conceived in the pre-monsoon season had an increased probability to be stunted. The median age at menarche was 13.0 years. Children that were stunted in infancy and childhood had later pubertal development as compared to non-stunted children. Children that recovered from stunting had a similar timing of puberty as their peers who had never been stunted. Supplementation with combined early prenatal food and multiple micronutrients was highly cost-effective in averting DALYs from under-five deaths and stunting. The results from this thesis support the conclusion that a lifecycle approach is needed for the prevention of stunting. The gaps between current knowledge, policy and practice needs to be closed, with more emphasis given to prenatal interventions