The impact of lipid-based nutrient supplement provision to pregnant women on newborn size in rural Malawi: a randomized controlled trial

Background: Small birth size, often associated with insufficient maternal nutrition, contributes to a large share of global child undernutrition, morbidity, and mortality. We developed a small-quantity lipid-based nutrient supplement (SQ-LNS) to enrich the diets of pregnant women. Objective: The objective was to test a hypothesis that home fortification of pregnant women's diets with SQ-LNS would increase birth size in an African community. Design: We enrolled 1391 women with uncomplicated pregnancies (<20 gestational weeks) in a randomized controlled trial in Malawi. The women were provided with one daily Iron folic acid (IFA) capsule, one capsule containing multiple micronutrients (MMNs), or one 20-g sachet of SQ-LNS (LNS, containing 118 kcal, protein, carbohydrates, essential fatty acids, and 21 micronutrients). Primary outcomes were birth weight and newborn length. Secondary outcomes included newborn weight, head and arm circumference, and pregnancy duration. Analysis was by intention to treat. Results: The mean +/- SD birth weight and newborn length were 2948 +/- 432, 2964 +/- 460, and 3000 +/- 447 g (P = 0.258) and 49.5 +/- 2.4, 49.7 +/- 2.2, and 49.9 +/- 2.1 cm (P = 0.104) in the IFA, MMN, and LNS groups, respectively. For newborn weight-for-age, head circumference, and arm circumference, the point estimate for the mean was also highest in the LNS group, intermediate in the MMN group, and lowest in the IFA group, but except for midupper arm circumference (P = 0.024), the differences were not statistically significant. The prevalence of low birth weight (<2500 g) was 12.7%, 13.5%, and 12.1% (P = 0.856), respectively; newborn stunting (length-for-age z score < -2) was 19.2%, 14.0%, and 14.9% (P = 0.130), respectively; and newborn small head circumference (head circumference-for-age z score < -2) was 5.8%, 3.0%, and 3.1% (P = 0.099), respectively. The associations between the intervention and the outcomes were not modified by maternal parity, age, or nutritional status (P > 0.100). Conclusion: The study findings do not support a hypothesis that provision of SQ-LNS to all pregnant women would increase the mean birth size in rural Malawi. The trial was registered at clinicaltrials.gov as NCT01239693.