Dominique Roberfroid

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

BackgroundPrevious 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).MethodsData 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.ResultsNulliparous, 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.ConclusionsNulliparous 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.FundingFunding 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.

Mortality risk in preterm and small-for-gestational-age infants in low-income and middle-income countries: a pooled country analysis

BACKGROUND Babies with low birthweight (<2500 g) are at increased risk of early mortality. However, low birthweight includes babies born preterm and with fetal growth restriction, and not all these infants have a birthweight less than 2500 g. We estimated the neonatal and infant mortality associated with these two characteristics in low-income and middle-income countries. METHODS For this pooled analysis, we searched all available studies and identified 20 cohorts (providing data for 2,015,019 livebirths) from Asia, Africa, and Latin America that recorded data for birthweight, gestational age, and vital statistics through 28 days of life. Study dates ranged from 1982 through to 2010. We calculated relative risks (RR) and risk differences (RD) for mortality associated with preterm birth (<32 weeks, 32 weeks to <34 weeks, 34 weeks to <37 weeks), small-for-gestational-age (SGA; babies with birthweight in the lowest third percentile and between the third and tenth percentile of a US reference population), and preterm and SGA combinations. FINDINGS Pooled overall RRs for preterm were 6·82 (95% CI 3·56-13·07) for neonatal mortality and 2·50 (1·48-4·22) for post-neonatal mortality. Pooled RRs for babies who were SGA (with birthweight in the lowest tenth percentile of the reference population) were 1·83 (95% CI 1·34-2·50) for neonatal mortality and 1·90 (1·32-2·73) for post-neonatal mortality. The neonatal mortality risk of babies who were both preterm and SGA was higher than that of babies with either characteristic alone (15·42; 9·11-26·12). INTERPRETATION Many babies in low-income and middle-income countries are SGA. Preterm birth affects a smaller number of neonates than does SGA, but is associated with a higher mortality risk. The mortality risks associated with both characteristics extend beyond the neonatal period. Differentiation of the burden and risk of babies born preterm and SGA rather than with low birthweight could guide prevention and management strategies to speed progress towards Millennium Development Goal 4--the reduction of child mortality. FUNDING Bill & Melinda Gates Foundation.

National and regional estimates of term and preterm babies born small for gestational age in 138 low-income and middle-income countries in 2010

Summary Background National estimates for the numbers of babies born small for gestational age and the comorbidity with preterm birth are unavailable. We aimed to estimate the prevalence of term and preterm babies born small for gestational age (term-SGA and preterm-SGA), and the relation to low birthweight (<2500 g), in 138 countries of low and middle income in 2010. Methods Small for gestational age was defined as lower than the 10th centile for fetal growth from the 1991 US national reference population. Data from 22 birth cohort studies (14 low-income and middle-income countries) and from the WHO Global Survey on Maternal and Perinatal Health (23 countries) were used to model the prevalence of term-SGA births. Prevalence of preterm-SGA infants was calculated from meta-analyses. Findings In 2010, an estimated 32·4 million infants were born small for gestational age in low-income and middle-income countries (27% of livebirths), of whom 10·6 million infants were born at term and low birthweight. The prevalence of term-SGA babies ranged from 5·3% of livebirths in east Asia to 41·5% in south Asia, and the prevalence of preterm-SGA infants ranged from 1·2% in north Africa to 3·0% in southeast Asia. Of 18 million low-birthweight babies, 59% were term-SGA and 41% were preterm. Two-thirds of small-for-gestational-age infants were born in Asia (17·4 million in south Asia). Preterm-SGA babies totalled 2·8 million births in low-income and middle-income countries. Most small-for-gestational-age infants were born in India, Pakistan, Nigeria, and Bangladesh. Interpretation The burden of small-for-gestational-age births is very high in countries of low and middle income and is concentrated in south Asia. Implementation of effective interventions for babies born too small or too soon is an urgent priority to increase survival and reduce disability, stunting, and non-communicable diseases. Funding Bill & Melinda Gates Foundation by a grant to the US Fund for UNICEF to support the activities of the Child Health Epidemiology Reference Group (CHERG).

Risk of childhood undernutrition related to small-for-gestational age and preterm birth in low- and middle-income countries

BACKGROUND Low- and middle-income countries continue to experience a large burden of stunting; 148 million children were estimated to be stunted, around 30-40% of all children in 2011. In many of these countries, foetal growth restriction (FGR) is common, as is subsequent growth faltering in the first 2 years. Although there is agreement that stunting involves both prenatal and postnatal growth failure, the extent to which FGR contributes to stunting and other indicators of nutritional status is uncertain. METHODS Using extant longitudinal birth cohorts (n=19) with data on birthweight, gestational age and child anthropometry (12-60 months), we estimated study-specific and pooled risk estimates of stunting, wasting and underweight by small-for-gestational age (SGA) and preterm birth. RESULTS We grouped children according to four combinations of SGA and gestational age: adequate size-for-gestational age (AGA) and preterm; SGA and term; SGA and preterm; and AGA and term (the reference group). Relative to AGA and term, the OR (95% confidence interval) for stunting associated with AGA and preterm, SGA and term, and SGA and preterm was 1.93 (1.71, 2.18), 2.43 (2.22, 2.66) and 4.51 (3.42, 5.93), respectively. A similar magnitude of risk was also observed for wasting and underweight. Low birthweight was associated with 2.5-3.5-fold higher odds of wasting, stunting and underweight. The population attributable risk for overall SGA for outcomes of childhood stunting and wasting was 20% and 30%, respectively. CONCLUSIONS This analysis estimates that childhood undernutrition may have its origins in the foetal period, suggesting a need to intervene early, ideally during pregnancy, with interventions known to reduce FGR and preterm birth.

Recurrence in tuberculosis: relapse or reinfection?

The importance of reinfection as a cause for recurrence of tuberculosis is unclear and has potential public-health implications. We systematically searched published material for studies using DNA fingerprinting to provide data on the issue. Very few studies were designed for that particular research objective and/or report on a sufficient number of observations. Differences in methods--eg, case-definitions--seriously hamper comparisons between studies. The proportion of recurrences due to reinfection ranged between 0% and 100%; however, this figure cannot be a useful indicator since the two causes of recurrence--relapse and reinfection--are essentially independent. Only one study provides an estimate of the incidence of recurrence due to reinfection, indicating its importance for HIV-infected patients in an environment with an unusually high tuberculosis incidence. We argue that apart from extreme situations like this one the problem of recurrence of tuberculosis due to reinfection has few implications for tuberculosis-control programmes.

Effectiveness of preventive school-based obesity interventions in low- and middle-income countries: a systematic review

BACKGROUND The prevalence of childhood obesity is increasing rapidly in low- and middle-income countries, and informed policies to tackle the problem must be defined. OBJECTIVE We systematically reviewed the evidence on the effectiveness of school-based interventions targeting dietary behavior and/or physical activity for the primary prevention of obesity in children and adolescents aged 6-18 y in low- and middle-income countries. DESIGN We searched the MEDLINE, EMBASE, Web of Science, CENTRAL, ERIC, Cochrane Library, and Centre for Reviews and Dissemination databases for peer-reviewed controlled studies published in English, Spanish, French, German, or Dutch between January 1990 and July 2011. The quality of the included studies was appraised independently by 2 authors who used the Effective Public Health Practice Project tool. RESULTS From a total of 7218 unique references, we retained 22 studies. Most of the interventions (82%) had a positive effect on dietary behavior and physical activity behavior (effect size ranged from -0.48 to 1.61). BMI decreased in 8 studies (effect size ranged from -0.7 to 0.0). Effective interventions targeted both diet and physical activity, involved multiple stakeholders, and integrated educational activities into the school curriculum. CONCLUSIONS School-based interventions have the potential to improve dietary and physical activity behavior and to prevent unhealthy body weights in low- and middle-income countries. To reach their full potential, interventions should conduct process evaluations to document program implementation. The effect and the pathways through which interventions have this effect need to be better documented through rigorous evaluation studies.

Fumonisin exposure through maize in complementary foods is inversely associated with linear growth of infants in Tanzania

Infants consuming maize-based foods are at a high risk of exposure to fumonisins. This study explored the association between exposure of fumonisins from maize and growth retardation among infants in Tanzania. Mothers of 215 infants consented for their children to participate in this study. We estimated maize intake for each child by twice conducting a 24 h dietary recall and fumonisins level in the maize, using HPLC. Fumonisins exposure for each child was estimated by combining his/her maize intake and the fumonisins level in the maize. Of the infants, 191 consumed maize. The maize consumed by 131 infants contained fumonisins at levels varying from 21 to 3201 μg/kg. Fumonisins exposure in 26 infants exceeded the provisional maximum tolerable daily intake of 2 μg/kg body weight. At 12 months of age, infants exposed to fumonisins intakes above the provisional maximum tolerable daily intake of 2 μg/kg bodyweight were significantly shorter by 1.3 cm and 328 g lighter. It appears that the exposure to fumonisins is associated with growth retardation. This is the first study to report an association between fumonisins exposures and growth retardation.

Prenatal food supplementation fortified with multiple micronutrients increases birth length: a randomized controlled trial in rural Burkina Faso

BACKGROUND Prenatal multiple micronutrient (MMN) or balanced energy and protein supplementation has a limited effect on birth size of the offspring. OBJECTIVE The objective was to determine whether a prenatal MMN-fortified food supplement (FFS) improves anthropometric measures at birth compared with supplementation with an MMN pill alone. DESIGN We conducted a nonblinded, individually randomized controlled trial in 1296 pregnant women in 2 villages in rural Burkina Faso. Supplements were provided on a daily basis, and compliance was closely verified by using a community-based network of home visitors. RESULTS Anthropometric measures at birth were available for analysis for 87% of the 1175 live singleton deliveries enrolled. After adjustment for gestational age at birth, the FFS group had a significantly higher birth length (+4.6 mm; P = 0.001). FFS supplementation resulted in a modestly higher birth weight (+31 g; P = 0.197). Subgroup analyses showed clinically important treatment effects on birth length (+12.0 mm; P = 0.005) and on birth weight (+111 g; P = 0.133) for underweight [body mass index (in kg/m(2)) <18.5] pregnant women. Women with early pregnancy anemia who received FFS gave birth to longer newborns (+7.3 mm; P = 0.002) than did those who received MMN supplementation. CONCLUSIONS The provision of FFS to pregnant women resulted in higher birth length than did MMN supplementation. For women with a suboptimal prepregnancy nutritional status, MMN supplementation should be complemented with a balanced energy and protein supplement to produce a clinical effect on birth size. The trial was registered at clinicaltrials.gov as NCT00909974.

The Effect of Adding Ready-to-Use Supplementary Food to a General Food Distribution on Child Nutritional Status and Morbidity: A Cluster-Randomized Controlled Trial

Lieven Huybregts and colleagues investigate how supplementing a general food distribution with a fortified lipid-based spread during a seasonal hunger gap in Chad affects anthropometric and morbidity outcomes for children aged 6 to 36 months.

Eating out of home in Vietnamese adolescents: socioeconomic factors and dietary associations

BACKGROUND Out-of-home (OH) eating in developed countries is associated with suboptimal dietary intakes, but evidence is scarce on the situation in developing countries. OBJECTIVE The objective of this study was to determine the nutritional contribution of OH eating and related socioeconomic determinants in Vietnamese adolescents. DESIGN A 24-h recall was used to collect food intake data in a cross-sectional study of 1172 adolescents living in urban and rural areas. Multilevel analysis compared the mean daily intakes of energy, energy density, energy from fat, food groups, vitamin A, iron, and zinc in low, middle, and high consumers of OH food. Socioeconomic associations of OH eating were analyzed in a subsample of 870 adolescents. RESULTS OH foods contributed 42% of fruit and vegetables, 23% of sodium, 21% of energy, 21% of vitamin A, 21% of iron, and 21% of zinc consumed per day. OH eating was negatively associated with total energy intake and energy density and positively associated with dietary diversity, energy contribution from fat, and consumption of sugar products. In rural areas, OH eating was positively associated with iron, fruit, meat, poultry, and offal intake. Female sex (P < 0.001), residence in urban areas (P < 0.001), and amount of pocket money (P < 0.001) were positively associated with consumption of OH foods. CONCLUSIONS OH eating added a number of desirable foods and nutrients but was also associated with higher consumption of energy from fat and sugar products. Independent of household wealth and locality, pocket money and sex are important determinants of OH eating.