Maternal Preconception Body Size and Early Childhood Growth during Prenatal and Postnatal Periods Are Positively Associated with Child-Attained Body Size at Age 6–7 Years: Results from a Follow-up of the PRECONCEPT Trial

BACKGROUND: Growth faltering is associated with adverse consequences during childhood and later life. However, questions remain on the relative importance of preconception maternal nutritional status (PMNS) and child growth during the first 1000 d of life. OBJECTIVES: We examined associations between PMNS, gestational weight gain (GWG), and child growth during the first 1000 d with attained body size at age 6–7 y. METHODS: We used data from a follow-up of a double-blinded randomized controlled trial of preconception micronutrient supplementation in Vietnam (n = 5011 women). The outcomes included offspring height-for-age z score (HAZ), BMI-for-age z score (BMIZ), and prevalence of stunting and overweight/obese at age 6–7 y (n = 1579). We used multivariable linear and Poisson regression models to evaluate the relative contributions of PMNS (height and BMI), GWG, and conditional growth in 4 periods: fetal, 0–6 mo, 6–12 mo, and 12–24 mo. RESULTS: PMNS was positively associated with child-attained size at 6–7 y. For each 1-SD higher maternal height and BMI, offspring had 0.28-SD and 0.13-SD higher HAZ at 6–7 y, respectively. Higher maternal BMI and GWG were associated with larger child BMIZ (β: 0.29 and 0.10, respectively). Faster linear growth, especially from 6 to 24 mo, had the strongest association with child HAZ at 6–7 y (β: 0.39–0.42), whereas conditional weight measures in all periods were similarly associated with HAZ (β: 0.10–0.15). For BMIZ at 6–7 y, the magnitude of association was larger and increased with child age for conditional weight gain (β: 0.21–0.41) but smaller for conditional length gain. Faster growth in the first 2 y was associated with reduced risk of stunting and thinness but increased risk of overweight/obese at 6–7 y. CONCLUSIONS: Interventions aimed at improving child growth while minimizing the risk of overweight during the school age years should target both women of reproductive age prior to conception through delivery and their offspring during the first 1000 d. The trial was registered at clinicaltrials.gov as NCT01665378.