Vulnerable newborn types: analysis of subnational, population-based birth cohorts for 541 285 live births in 23 countries, 2000-2021.

OBJECTIVE: To examine prevalence of novel newborn types among 541 285 live births in 23 countries from 2000 to 2021. DESIGN: Descriptive multi-country secondary data analysis. SETTING: Subnational, population-based birth cohort studies (n = 45) in 23 low- and middle-income countries (LMICs) spanning 2000-2021. POPULATION: Liveborn infants. METHODS: Subnational, population-based studies with high-quality birth outcome data from LMICs were invited to join the Vulnerable Newborn Measurement Collaboration. We defined distinct newborn types using gestational age (preterm [PT], term [T]), birthweight for gestational age using INTERGROWTH-21st standards (small for gestational age [SGA], appropriate for gestational age [AGA] or large for gestational age [LGA]), and birthweight (low birthweight, LBW [<2500 g], nonLBW) as ten types (using all three outcomes), six types (by excluding the birthweight categorisation), and four types (by collapsing the AGA and LGA categories). We defined small types as those with at least one classification of LBW, PT or SGA. We presented study characteristics, participant characteristics, data missingness, and prevalence of newborn types by region and study. RESULTS: Among 541 285 live births, 476 939 (88.1%) had non-missing and plausible values for gestational age, birthweight and sex required to construct the newborn types. The median prevalences of ten types across studies were T+AGA+nonLBW (58.0%), T+LGA+nonLBW (3.3%), T+AGA+LBW (0.5%), T+SGA+nonLBW (14.2%), T+SGA+LBW (7.1%), PT+LGA+nonLBW (1.6%), PT+LGA+LBW (0.2%), PT+AGA+nonLBW (3.7%), PT+AGA+LBW (3.6%) and PT+SGA+LBW (1.0%). The median prevalence of small types (six types, 37.6%) varied across studies and within regions and was higher in Southern Asia (52.4%) than in Sub-Saharan Africa (34.9%). CONCLUSIONS: Further investigation is needed to describe the mortality risks associated with newborn types and understand the implications of this framework for local targeting of interventions to prevent adverse pregnancy outcomes in LMICs.

Maternal supplementation with vitamin A or ß-carotene and cardiovascular risk factors among pre-adolescent children in rural Nepal.

Vitamin A plays an important role in fetal renal and cardiovascular development, yet there has been little research on its effects on cardiovascular risk factors later in childhood. To examine this question, we followed the children of women who had been participants in a cluster-randomized, double blind, placebo-controlled trial of weekly supplementation with 7000 µg retinol equivalents of preformed vitamin A or 42 mg of ß-carotene from 1994 to 1997 in rural Nepal. Women received their assigned supplements before, during and after pregnancy. Over a study period of 3 years, 17,531 infants were born to women enrolled in the trial. In 2006-2008, we revisited and assessed 13,118 children aged 9-13 years to examine the impact of maternal supplementation on early biomarkers of chronic disease. Blood pressure was measured in the entire sample of children. In a subsample of 1390 children, venous blood was collected for plasma glucose, Hb1Ac and lipids and a morning urine specimen was collected to measure the ratio of microalbumin/creatinine. Detailed anthropometry was also conducted in the subsample. The mean ± s.d. systolic and diastolic blood pressure was 97.2 ± 8.2 and 64.6 ± 8.5 mm Hg, respectively, and about 5.0% had high-blood pressure (⩾120/80 mm Hg). The prevalence of microalbuminuria (⩾30 mg/g creatinine) was also low at 4.8%. There were no differences in blood pressure or the risk of microalbuminuria between supplement groups. There were also no group differences in fasting glucose, glycated hemoglobin, triglycerides or cholesterol. Maternal supplementation with vitamin A or ß-carotene had no overall impact on cardiovascular risk factors in this population at pre-adolescent age in rural Nepal.

Seasonality in urinary and household salt iodine content among pregnant and lactating women of the plains of Nepal.

OBJECTIVE: To determine the extent and causes of iodine deficiency among women during pregnancy and lactation in the southeastern plains of Nepal. DESIGN, SETTING AND SUBJECTS: Urinary iodine (UI) was assessed as an indicator of iodine status in spot urine samples of women participating in a field trial in three rural communities in the plains of southeastern Nepal. Samples were collected during pregnancy (n=1021) and during lactation at 3-4 months postpartum (n=1028) at a central clinic; 613 women were assessed at both times. Salt iodine (SI) content was assessed semiquantitatively at 6-7 months postpartum in households (n=1572). RESULTS: During pregnancy and lactation, median UI concentrations were 0.756 and 0.483 micromol/l, respectively, indicating mild iodine deficiency. UI and SI concentrations covaried markedly by season and were highest during hot, dry, premonsoon months and lowest during and following the humid monsoon season. Within women who contributed urine samples during both pregnancy and the postpartum period, iodine status determined by UI was not correlated. The percentage of households with adequately iodized salt (30 ppm) ranged from 85 to 44% from the hot, dry to the humid seasons, respectively. CONCLUSIONS: In the rural southern plains of Nepal, iodine deficiency remains a mild-to-moderate public health problem among pregnant and lactating women despite the availability of iodized salt. Marked seasonality in SI content may account for the lack of intraindividual correlation between maternal iodine status during pregnancy and postpartum periods and contribute to periodicity in the risk of iodine deficiency.