Effects of antenatal multiple micronutrient supplementation on children's weight and size at 2 years of age in Nepal: follow-up of a double-blind randomised controlled trial

BACKGROUND The negative effects of low birthweight on the later health of children in developing countries have been well studied. However, undertaking programmes to address this issue can be difficult since there is no simple correlation between increasing birthweight and improving child health. In 2005, we published results of a randomised controlled trial in Nepal, in which 1200 women received either iron and folic acid or a supplement that provided the recommended daily allowance of 15 vitamins and minerals, over the second and third trimesters of pregnancy. Here, we report on 2-3 years' follow-up of children born during the trial. METHODS We visited children at home and obtained data for the primary outcomes of weight and height, for childhood illnesses, and maternal blood haemoglobin. The study is registered as an International Standard Randomised Controlled Trial, number ISRCTN88625934. FINDINGS Between December, 2005, and December, 2006, we assessed 917 children (455 controls, 462 intervention) at a mean age of 2.5 years. Mean birthweight had been 77 g (95% CI 24-130) greater in the micronutrient group than in controls. At 2.5 years old, controls weighed a mean of 10.7 kg (SD 1.38), and those in the intervention group 10.9 kg (SD 1.54). Children of women who had taken multiple micronutrient supplements during pregnancy were a mean 204 g (95% CI 27-381) heavier than controls. They also had greater measurements than controls in the circumference of the head (2.4 mm [95% CI 0.6-4.3]), chest (3.2 mm [0.4-6.0]), and mid-upper arm (2.4 mm [1.1-3.7]), and in triceps skinfold thickness (2.0 mm [0.0-0.4]). Systolic blood pressure was slightly lower in the intervention group (2.5 mm Hg [0.5-4.6]). INTERPRETATION In a poor population, the effects of maternal multiple micronutrient supplementation on the fetus persisted into childhood, with increases in both weight and body size. These increases were small, however, since those exposed to micronutrients had an average of 2% higher weight than controls. The public-health implications of changes in weight and blood pressure need to be clarified through further follow-up.