Peer-reviewed article
Exploring Infant Size and Body Composition at 18 Months: An Ambidirectional Peri-Urban South African Cohort Study.
H Mulol, S Nel, F A M Wenhold, U D Feucht ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This South African study followed infants from pregnancy through 18 months to understand what factors affect their body size and composition. Researchers found that poor placental function during pregnancy, maternal HIV infection, and household food insecurity all led to smaller, thinner infants at 18 months. The findings show that nutrition-related problems before and after birth have lasting effects on child growth and development.
Key points
- Poor placental function (measured by umbilical artery resistance) predicted lower birthweight and reduced infant length at 18 months
- Maternal HIV infection was associated with reduced infant length-for-age Z-score at 18 months
- Household food insecurity predicted reduced fat-free mass (lean body mass) at 18 months
- The study included prenatal, perinatal and postnatal factors in an ambidirectional design
- Outcomes showed long-term consequences including stunting with impacts on the individual, future generations and society
Limitations
The study was conducted in a peri-urban area of South Africa among women at low risk of adverse pregnancy outcomes, so findings may not generalise to other populations or settings. The cross-sectional analysis at 18 months does not establish causality or allow assessment of longer-term developmental outcomes.
Abstract
The first 1000 days of life lay the foundations for subsequent growth. This ambidirectional study, including prenatal, perinatal and postnatal factors, aimed to identify exposure variables affecting body size and composition and corresponding Z-score outcomes at age 18 months in infants born to women at low risk of adverse pregnancy outcomes in a peri-urban area of South Africa. Prenatal factors (maternal age, HIV status, anthropometry, parity, food insecurity and umbilical artery resistance index Z-score (UmA-RIAZ) as a measure of placental function, with higher UmA-RIAZ indicating poorer placental function); perinatal factors (infant sex, gestational age and birth anthropometry) and postnatal factors (infant feeding) were included as exposure variables, with infant anthropometry and body composition at 18 months as outcomes. Simple linear regression analysis was used to investigate associations between exposure variables and infant outcomes, and variables with p < 0.10 were included in the subsequent multiple regression analyses. Multiple regression analysis showed that higher UmA-RIAZ predicted lower birthweight [-0.11 kg (95% CI: -0.17, -0.04 kg)], birthweight-for-age Z-score [-0.24 (95% CI: -0.39, -0.09)] and 18-month infant length [-0.9 cm (95% CI: -1.4, -0.4 cm)] and length-for-age Z-score [-0.28 (95% CI: -0.45, -0.11)]. Maternal HIV infection predicted reduced 18-month infant length-for-age Z-score [-0.46 (95% CI: -0.83, -0.09)]. Household food insecurity predicted reduced fat-free mass-for-age Z-score at 18 months [-0.27 (95% CI: -0.51, -0.03)]. Infant anthropometry and body composition outcomes, therefore, are greatly affected by pre- and postnatal nutrition-related factors, such as placental insufficiency in utero and household food insecurity, with long-term consequences including stunting, which impact the individual, future generations and society.