Prevalence of Small-for-Gestational-Age and Its Mortality Risk Varies by Choice of Birth-Weight-for-Gestation Reference Population

Abstract

BackgroundWe use data from rural Nepal and South India to compare the prevalence of small-for-gestational-age (SGA) and neonatal mortality risk associated with SGA using different birth-weight-for-gestation reference populations.MethodsWe identified 46 reference populations in low-, middle-, and high-income countries, of which 26 met the inclusion criteria of being commonly cited and having numeric 10th percentile cut points published. Those reference populations were then applied to populations from two community-based studies to determine SGA prevalence and its relative risk of neonatal mortality.ResultsThe prevalence of SGA ranged from 10.5% to 72.5% in Nepal, and 12.0% to 78.4% in India, depending on the reference population. Females had higher rates of SGA than males using reference populations that were not sex specific. SGA prevalence was lowest when using reference populations from low-income countries. Infants who were both preterm and SGA had much higher mortality risk than those who were term and appropriate-for-gestational-age. Risk ratios for those who are both preterm and SGA ranged from 7.34–17.98 in Nepal and 5.29–11.98 in India, depending on the reference population.ConclusionsThese results demonstrate the value of a common birth-weight-for-gestation reference population that will facilitate comparisons of SGA prevalence and mortality risk across research studies.

Early motor repertoire in very low birth weight infants in India is associated with motor development at one year

“…(2, 23-26) Numbers from India are scarce, and the high incidence of fetal growth restriction (27,28) results in a higher proportion of small but more mature infants when birth weight is used as an inclusion criterion. Another explanation for the small number of children with abnormal FMs and a poor motor performance at 12 months might be that the most severely ill infants do not survive the neonatal period.…”

Gestational Age and Pregnancy Outcomes

“…Preterm birth can further be subdivided on the basis of gestational age: extremely preterm (<28 weeks), very preterm (28-32 weeks), and moderate or late preterm [32][33][34][35][36][37] completed weeks of gestation. Since decreasing gestational age is associated with increasing mortality, disability, and cost due to intensity of neonatal care, these subdivisions are important [7].…”

“…Thus, in low-and middle-income countries, about one in five infants is born small for gestational age (as compared to 16% among blacks and 9% SGA in 200 in the United States), and one in four deaths is among such infants [36]. Growth restriction in infants can be due to many factors including poor maternal nutrition, maternal infections, congenital defects, smoking, and placental conditions [36]. SGA can also arise from genetic predisposition to small size.…”

Fetal programming and systemic sclerosis

“…20 In clinical practice, SGA commonly is defined as a birthweight <10th percentile for gestational age and sex relative to the population standard; it is used as a measurable proxy for intrauterine growth restriction and later health risks. 21 The study population was divided according to birthweight (<2500, !2500, or !4000 g) and gestational age (preterm, <37 weeks; at term, 37-41 weeks; postterm, >41 weeks). The association between LBW and SSc and between SGA and SSc was expressed with the odds ratio (OR) calculated with a univariate analysis that considered 2 birthweight groups (<2500 and !2500 g).…”