Cognitive and motor skills in school-aged children following maternal vitamin A supplementation during pregnancy in rural Nepal: a follow-up of a placebo-controlled, randomised cohort.

OBJECTIVE: To determine the effects of maternal vitamin A supplementation from preconception through postpartum on cognitive and motor development of children at 10-13 years of age in rural Nepal. DESIGN: Follow-up assessment of children born to women randomly assigned by a village to receive either supplemental vitamin A (7000 µg retinol equivalents) or placebo weekly during a continuous 3.5-year period from 1994-1997. The participants came from 12 wards, a subset of 270 wards in the original trial. Trained staff tested children for cognition by the Universal Nonverbal Intelligence Test (UNIT) and motor ability using four subtests from the Movement Assessment Battery for Children (MABC). Data on schooling, home environment and nutritional and socioeconomic status were also collected. SETTING: Southern plains district of Sarlahi, Nepal. PARTICIPANTS: 390 Nepalese children 10-13 years of age. MAIN OUTCOME MEASURES: Raw scores on UNIT and square-root transformed scores on an abridged version of the MABC tests, expressed as cluster-summarised (mean±SD) values to account for the design of the original trial. RESULTS: There were no differences in UNIT (79.61±5.99 vs 80.69±6.71) or MABC (2.64±0.07 vs 2.49±0.09) test scores in children whose mothers were exposed to vitamin A vs placebo (mean differences: -1.07, 95% CI -7.10 to 9.26, p=0.78; 0.15, 95% CI 0.43 to -0.08, p=0.15), respectively. More children in the placebo group had repeated a grade in school (28% of placebo vs 16.7% of vitamin A, p=0.01). CONCLUSIONS: Preconceptional to postpartum maternal vitamin A supplementation, in an undernourished setting, does not improve cognition or motor development at ages 10-13 years.

Multi-country analysis of the effects of diarrhoea on childhood stunting.

Diarrhoea is an important cause of death and illness among children in developing countries; however, it remains controversial as to whether diarrhoea leads to stunting. We conducted a pooled analysis of nine studies that collected daily diarrhoea morbidity and longitudinal anthropometry to determine the effects of the longitudinal history of diarrhoea prior to 24 months on stunting at age 24 months. Data covered a 20-year period and five countries. We used logistic regression to model the effect of diarrhoea on stunting. The prevalence of stunting at age 24 months varied by study (range 21-90%), as did the longitudinal history of diarrhoea prior to 24 months (incidence range 3.6-13.4 episodes per child-year, prevalence range 2.4-16.3%). The effect of diarrhoea on stunting, however, was similar across studies. The odds of stunting at age 24 months increased multiplicatively with each diarrhoeal episode and with each day of diarrhoea before 24 months (all P < 0.001). The adjusted odds of stunting increased by 1.13 for every five episodes (95% CI 1.07-1.19), and by 1.16 for every 5% unit increase in longitudinal prevalence (95% CI 1.07-1.25). In this assembled sample of 24-month-old children, the proportion of stunting attributed to >or=5 diarrhoeal episodes before 24 months was 25% (95% CI 8-38%) and that attributed to being ill with diarrhoea for >or=2% of the time before 24 months was 18% (95% CI 1-31%). These observations are consistent with the hypothesis that a higher cumulative burden of diarrhoea increases the risk of stunting.