To describe the mortality risks by fine strata of gestational age and birthweight among 230 679 live births in nine low- and middle-income countries (LMICs) from 2000 to 2017.
Descriptive ...multi-country secondary data analysis.
Nine LMICs in sub-Saharan Africa, Southern and Eastern Asia, and Latin America.
Liveborn infants from 15 population-based cohorts.
Subnational, population-based studies with high-quality birth outcome data were invited to join the Vulnerable Newborn Measurement Collaboration. All studies included birthweight, gestational age measured by ultrasound or last menstrual period, infant sex and neonatal survival. We defined adequate birthweight as 2500-3999 g (reference category), macrosomia as ≥4000 g, moderate low as 1500-2499 g and very low birthweight as <1500 g. We analysed fine strata classifications of preterm, term and post-term: ≥42
, 39
-41
(reference category), 37
-38
, 34
-36
,34
-36
,32
-33
, 30
-31
, 28
-29
and less than 28 weeks.
Median and interquartile ranges by study for neonatal mortality rates (NMR) and relative risks (RR). We also performed meta-analysis for the relative mortality risks with 95% confidence intervals (CIs) by the fine categories, stratified by regional study setting (sub-Saharan Africa and Southern Asia) and study-level NMR (≤25 versus >25 neonatal deaths per 1000 live births).
We found a dose-response relationship between lower gestational ages and birthweights with increasing neonatal mortality risks. The highest NMR and RR were among preterm babies born at <28 weeks (median NMR 359.2 per 1000 live births; RR 18.0, 95% CI 8.6-37.6) and very low birthweight (462.8 per 1000 live births; RR 43.4, 95% CI 29.5-63.9). We found no statistically significant neonatal mortality risk for macrosomia (RR 1.1, 95% CI 0.6-3.0) but a statistically significant risk for all preterm babies, post-term babies (RR 1.3, 95% CI 1.1-1.5) and babies born at 37
-38
weeks (RR 1.2, 95% CI 1.0-1.4). There were no statistically significant differences by region or underlying neonatal mortality.
In addition to tracking vulnerable newborn types, monitoring finer categories of birthweight and gestational age will allow for better understanding of the predictors, interventions and health outcomes for vulnerable newborns. It is imperative that all newborns from live births and stillbirths have an accurate recorded weight and gestational age to track maternal and neonatal health and optimise prevention and care of vulnerable newborns.
We aimed to understand the mortality risks of vulnerable newborns (defined as preterm and/or born weighing smaller or larger compared to a standard population), in low- and middle-income countries ...(LMICs).
Descriptive multi-country, secondary analysis of individual-level study data of babies born since 2000.
Sixteen subnational, population-based studies from nine LMICs in sub-Saharan Africa, Southern and Eastern Asia, and Latin America.
Live birth neonates.
We categorically defined five vulnerable newborn types based on size (large- or appropriate- or small-for-gestational age LGA, AGA, SGA), and term (T) and preterm (PT): T + LGA, T + SGA, PT + LGA, PT + AGA, and PT + SGA, with T + AGA (reference). A 10-type definition included low birthweight (LBW) and non-LBW, and a four-type definition collapsed AGA/LGA into one category. We performed imputation for missing birthweights in 13 of the studies.
Median and interquartile ranges by study for the prevalence, mortality rates and relative mortality risks for the four, six and ten type classification.
There were 238 143 live births with known neonatal status. Four of the six types had higher mortality risk: T + SGA (median relative risk RR 2.8, interquartile range IQR 2.0-3.2), PT + LGA (median RR 7.3, IQR 2.3-10.4), PT + AGA (median RR 6.0, IQR 4.4-13.2) and PT + SGA (median RR 10.4, IQR 8.6-13.9). T + SGA, PT + LGA and PT + AGA babies who were LBW, had higher risk compared with non-LBW babies.
Small and/or preterm babies in LIMCs have a considerably increased mortality risk compared with babies born at term and larger. This classification system may advance the understanding of the social determinants and biomedical risk factors along with improved treatment that is critical for newborn health.
Abstract
Objective
We aimed to understand the mortality risks of vulnerable newborns (defined as preterm and/or born weighing smaller or larger compared to a standard population), in low‐ and ...middle‐income countries (LMICs).
Design
Descriptive multi‐country, secondary analysis of individual‐level study data of babies born since 2000.
Setting
Sixteen subnational, population‐based studies from nine LMICs in sub‐Saharan Africa, Southern and Eastern Asia, and Latin America.
Population
Live birth neonates.
Methods
We categorically defined five vulnerable newborn types based on size (large‐ or appropriate‐ or small‐for‐gestational age LGA, AGA, SGA), and term (T) and preterm (PT): T + LGA, T + SGA, PT + LGA, PT + AGA, and PT + SGA, with T + AGA (reference). A 10‐type definition included low birthweight (LBW) and non‐LBW, and a four‐type definition collapsed AGA/LGA into one category. We performed imputation for missing birthweights in 13 of the studies.
Main Outcome Measures
Median and interquartile ranges by study for the prevalence, mortality rates and relative mortality risks for the four, six and ten type classification.
Results
There were 238 203 live births with known neonatal status. Four of the six types had higher mortality risk: T + SGA (median relative risk RR 2.6, interquartile range IQR 2.0–2.9), PT + LGA (median RR 7.3, IQR 2.3–10.4), PT + AGA (median RR 6.0, IQR 4.4–13.2) and PT + SGA (median RR 10.4, IQR 8.6–13.9). T + SGA, PT + LGA and PT + AGA babies who were LBW, had higher risk compared with non‐LBW babies.
Conclusions
Small and/or preterm babies in LIMCs have a considerably increased mortality risk compared with babies born at term and larger. This classification system may advance the understanding of the social determinants and biomedical risk factors along with improved treatment that is critical for newborn health.
To estimate the associations between gestational weight gain (GWG) during pregnancy and neonatal outcomes in low and middle income countries.
Individual participant data meta-analysis.
Prospective ...pregnancy studies from 24 low and middle income countries.
Nine neonatal outcomes related to timing (preterm birth) and anthropometry (weight, length, and head circumference) at birth, stillbirths, and neonatal death.
A systematic search was conducted in PubMed, Embase, and Web of Science which identified 53 prospective pregnancy studies published after the year 2000 with data on GWG, timing and anthropometry at birth, and neonatal mortality. GWG adequacy was defined as the ratio of the observed maternal weight gain over the recommended weight gain based on the Institute of Medicine body mass index specific guidelines, which are derived from data in high income settings, and the INTERGROWTH-21st GWG standards. Study specific estimates, adjusted for confounders, were generated and then pooled using random effects meta-analysis models. Maternal age and body mass index before pregnancy were examined as potential modifiers of the associations between GWG adequacy and neonatal outcomes.
Overall, 55% of participants had severely inadequate (<70%) or moderately inadequate (70% to <90%) GWG, 22% had adequate GWG (90-125%), and 23% had excessive GWG (≥125%). Severely inadequate GWG was associated with a higher risk of low birthweight (adjusted relative risk 1.62, 95% confidence interval 1.51 to 1.72; 48 studies, 93 337 participants; τ
=0.006), small for gestational age (1.44, 1.36 to 1.54; 51 studies, 93 191 participants; τ
=0.016), short for gestational age (1.47, 1.29 to 1.69; 40 studies, 83 827 participants; τ
=0.074), and microcephaly (1.57, 1.31 to 1.88; 31 studies, 80 046 participants; τ
=0.145) compared with adequate GWG. Excessive GWG was associated with a higher risk of preterm birth (1.22, 1.13 to 1.31; 48 studies, 103 762 participants; τ
=0.008), large for gestational age (1.44, 1.33 to 1.57; 47 studies, 90 044 participants; τ
=0.009), and macrosomia (1.52, 1.33 to 1.73; 29 studies, 68 138 participants; τ
=0) compared with adequate GWG. The direction and magnitude of the associations between GWG adequacy and several neonatal outcomes were modified by maternal age and body mass index before pregnancy.
Inadequate and excessive GWG are associated with a higher risk of adverse neonatal outcomes across settings. Interventions to promote optimal GWG during pregnancy are likely to reduce the burden of adverse neonatal outcomes, however further research is needed to assess optimal ranges of GWG based on data from low and middle income countries.
Many women experience suboptimal gestational weight gain (GWG) in low- and middle-income countries (LMICs), but our understanding of risk factors associated with GWG in these settings is limited. We ...investigated the relationships between demographic, anthropometric, lifestyle, and clinical factors and GWG in prospectively collected data from LMICs.
We conducted an individual participant-level meta-analysis of risk factors for GWG outcomes among 138,286 pregnant women with singleton pregnancies in 55 studies (27 randomized controlled trials and 28 prospective cohorts from 25 LMICs). Data sources were identified through PubMed, Embase, and Web of Science searches for articles published from January 2000 to March 2019. Titles and abstracts of articles identified in all databases were independently screened by 2 team members according to the following eligibility criteria: following inclusion criteria: (1) GWG data collection took place in an LMIC; (2) the study was a prospective cohort or randomized trial; (3) study participants were pregnant; and (4) the study was not conducted exclusively among human immunodeficiency virus (HIV)-infected women or women with other health conditions that could limit the generalizability of the results. The Institute of Medicine (IOM) body mass index (BMI)-specific guidelines were used to determine the adequacy of GWG, which we calculated as the ratio of the total observed weight gain over the mean recommended weight gain. Study outcomes included severely inadequate GWG (percent adequacy of GWG <70), inadequate GWG (percent adequacy of GWG <90, inclusive of severely inadequate), and excessive GWG (percent adequacy of GWG >125). Multivariable estimates from each study were pooled using fixed-effects meta-analysis. Study-specific regression models for each risk factor included all other demographic risk factors measured in a particular study as potential confounders, as well as BMI, maternal height, pre-pregnancy smoking, and chronic hypertension. Risk factors occurring during pregnancy were further adjusted for receipt of study intervention (if any) and 3-month calendar period. The INTERGROWTH-21st standard was used to define high and low GWG among normal weight women in a sensitivity analysis. The prevalence of inadequate GWG was 54%, while the prevalence of excessive weight gain was 22%. In multivariable models, factors that were associated with a higher risk of inadequate GWG included short maternal stature (<145 cm), tobacco smoking, and HIV infection. A mid-upper arm circumference (MUAC) of ≥28.1 cm was associated with the largest increase in risk for excessive GWG (risk ratio (RR) 3.02, 95% confidence interval (CI) 2.86, 3.19). The estimated pooled difference in absolute risk between those with MUAC of ≥28.1 cm compared to those with a MUAC of 24 to 28.09 cm was 5.8% (95% CI 3.1% to 8.4%). Higher levels of education and age <20 years were also associated with an increased risk of excessive GWG. Results using the INTERGROWTH-21st standard among normal weight women were similar but attenuated compared to the results using the IOM guidelines among normal weight women. Limitations of the study's methodology include differences in the availability of risk factors and potential confounders measured in each individual dataset; not all risk factors or potential confounders of interest were available across datasets and data on potential confounders collected across studies.
Inadequate GWG is a significant public health concern in LMICs. We identified diverse nutritional, behavioral, and clinical risk factors for inadequate GWG, highlighting the need for integrated approaches to optimizing GWG in LMICs. The prevalence of excessive GWG suggests that attention to the emerging burden of excessive GWG in LMICs is also warranted.
The acquisition of bipedal locomotion is an important aspect of gross motor development that ultimately affects the cognition of young children. Evidence for associations between nutrition-related ...variables and walking acquisition exist; however, questions remain about the importance of weight-for-length and dietary factors and the independent contribution of anemia and growth to walking. We examined the effect of nutritional factors on the acquisition of walking in a cross-sectional cohort of 4- to 17-mo old Nepali children (n = 485) adjusting for age, sex, caste, and socioeconomic status (SES). Participants were identified from census data collected in 1 village development committee in Sarlahi District and enrolled in a cross-sectional, community-based study between January and March 2002. Hemoglobin and erythrocyte protoporphyrin (EP) were measured at baseline using a heel-prick technique. The mean hemoglobin concentration was 101 ± 12.5 g/L; 58% were anemic (hemoglobin < 105 g/L), 2.1% were severely anemic (hemoglobin < 70 g/L), and 43% of the children had iron-deficiency anemia (hemoglobin < 105 g/L; EP >/= 90 micromol/mol heme). Growth was delayed, i.e., 33.7% were stunted and 20.6% were wasted. Multivariate logistic models that controlled for age, sex, caste, and SES revealed that children with higher length-for-age and weight-for-length Z-scores, no anemia, and meat consumption walked at an earlier age than children with lower scores, anemia, and no meat consumption. We conclude that growth, anemia, and diet are independently associated with delays in the onset of bipedal locomotion among young Nepali children.
Objective: This paper examines gender, caste and economic differentials in child mortality in the context of a cluster-randomized trial of vitamin A distribution, in order to determine whether or not ...the intervention narrowed these differentials. Design: The study involved secondary analysis of data from a placebo-controlled randomized field trial of vitamin A supplements. The study took place between 1989–1991 in rural Sarlahi District of Nepal, with 30 059 children age 6 to 60 months. The main outcome measures were differences in mortality between boys and girls, between highest Hindu castes and others, and between the poorest quintile and the four other quintiles. Results: Without vitamin A, girls in rural Nepal experience 26.1 deaths per 1000, which is 8.3 deaths more than the comparison population of boys. With vitamin A the mortality disadvantage of girls is nearly completely attenuated, at only 1.41 additional deaths per 1000 relative to boys. Vitamin A supplementation also narrowed mortality differentials among Hindu castes, but did not lower the concentration of mortality across quintiles of asset ownership. The vitamin A-related attenuation in mortality disadvantage from gender and caste is statistically significant. Conclusions: We conclude that universal supplementation with vitamin A narrowed differentials in child death across gender and caste in rural Nepal. Assuring high-coverage vitamin A distribution throughout Nepal could help reduce inequalities in child survival in this population.
The effect of supplementing 11,918 infants < 1 mo and 1-5 mo of age with vitamin A (15,000 and 30,000 micrograms retinol equivalents or 50,000 and 100,000 IU, respectively) or a placebo on subsequent ...4-mo mortality was assessed in a randomized, double-masked community trial in the rural plains of Nepal. There were 130 deaths (51.6/1000 child-y) in the control group and 150 deaths (57.1/1000 child-y) in the vitamin A group, yielding a relative risk of 1.11 (95% CI: 0.86, 1.42), which is indicative of no overall effect on early infant mortality. There was a tendency for the relative risk of mortality among vitamin A recipients to rise with improved nutritional status. These results suggest that distribution of a large oral dose of vitamin A to infants < 5-6 mo of age may not benefit short-term survival. This is in contrast with the results of trials in which older infants and children in this same population were supplemented.
Inconsistencies have been observed in the impact of vitamin A (VA) supplementation on early child growth. To help clarify this issue, a cohort of 3377 rural Nepalese, nonxerophthalmic children 12-60 ...mo of age were randomized by ward to receive vitamin A 60,000 micrograms retinol equivalents (RE) or placebo-control (300 RE) supplementation once every 4 mo and followed for 16 mo. VA had no impact on annual weight gain or linear growth. However, arm circumference (AC) and muscle area (MA) growth improved in VA recipients, by 0.13 cm and 25 mm2, respectively, over controls. Growth of children with xerophthalmia, who were treated with greater than or equal to 120,000 RE at base line, was also compared to that of nonxerophthalmic children, stratified by initial wasting status, and adjusted for sex, baseline age and measurement status. Among initially nonwasted children (AC greater than or equal to 13.5 cm), VA-treated xerophthalmic children (n = 86) gained 0.7 cm more in linear growth than nonxerophthalmic children. Among initially wasted children (AC 13.5 cm), VA-treated children (n
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