Infant motor development in rural Vietnam and intrauterine exposures to anaemia, iron deficiency and common mental disorders: a prospective community-based study

BACKGROUND: Antenatal anaemia, iron deficiency and common mental disorders (CMD) are prevalent in low- and middle-income countries. The aim of this study was to examine the direct and indirect effects of antenatal exposures to these risks and infant motor development. METHODS: A cohort of women who were pregnant with a single foetus and between 12 and 20 weeks pregnant in 50 randomly-selected rural communes in Ha Nam province was recruited. Participants provided data twice during pregnancy (early and late gestation) and twice after giving birth (8 weeks and 6 months postpartum). The Edinburgh Postnatal Depression Scale was used at all four data collection waves to detect CMD (score ≥ 4). Maternal anaemia (Hb < 11 g/dL) and iron deficiency (ferritin < 15 ng/mL) were evaluated at early and late gestation. Infants’ motor development was assessed by the Bayley of Infant and Toddler Development Motor Scales (BSID-M) at the age of six months. Direct and indirect effects of the exposures on the outcome were examined with Path analysis. RESULTS: In total, 497 of 523 (97%) eligible pregnant women were recruited and 418 mother-infant pairs provided complete data and were included in the analyses. The prevalence of anaemia was 21.5% in early pregnancy and 24.4% in late pregnancy. There was 4.1% iron deficiency at early pregnancy and 48.2% at late pregnancy. Clinically significant symptoms of CMD were apparent among 40% women in early pregnancy and 28% in late pregnancy. There were direct adverse effects on infant BSID-M scores at 6 months of age due to antenatal anaemia in late pregnancy (an estimated mean reduction of 2.61 points, 95% Confidence Interval, CI, 0.57 to 4.65) and CMD in early pregnancy (7.13 points, 95% CI 3.13 to 11.13). Iron deficiency and anaemia in early pregnancy were indirectly related to the outcome via anaemia during late pregnancy. CONCLUSIONS: Antenatal anaemia, iron deficiency, and CMD have a negative impact on subsequent infant motor development. These findings highlight the need to improve the quality of antenatal care when developing interventions for pregnant women that aim to optimise early childhood development in low- and middle-income countries.