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

Randomized controlled trial conducted in rural Malawi among pregnant women with uncomplicated pregnancies attending antenatal care. Women were enrolled early in pregnancy and randomized to SQ-LNS, iron-folic acid (IFA), or multiple micronutrient (MMN) supplementation; the SQ-LNS arm included 462 randomized participants.

The active intervention was a daily 20 g sachet of small-quantity lipid-based nutrient supplement (SQ-LNS) providing 118 kcal, taken orally by mixing with a small amount of food from enrollment until delivery. The SQ-LNS was delivered in 15 fortnightly doses and contained the same micronutrients as the MMN capsules plus 4 additional minerals, protein, and fat.

Overall, SQ-LNS did not significantly increase mean birth size in this setting. In the SQ-LNS arm, mean birth weight was 3000 g (SD 447) and mean newborn length was 49.9 cm (SD 2.1), but neither differed significantly across groups (birth weight P=0.258; newborn length P=0.104). Newborn MUAC was slightly higher with SQ-LNS than IFA (10.7 vs 10.5 cm, P=0.024), and the reported adjusted difference vs IFA was 0.2 (0.1, 0.3) mm higher (P=0.006), but key neonatal outcomes such as low birth weight, preterm birth, small-for-gestational age, stunting, underweight, and small head circumference were not significantly different. The authors concluded that providing SQ-LNS to all pregnant women in this setting did not support the hypothesis of improved mean birth size, though subgroup effects and longer-term child outcomes warrant further study.

The trial was conducted in a single rural Malawian setting, which limits generalizability. The main birth-size outcomes were not significantly improved, and several secondary findings were small, inconsistent, or borderline, raising the possibility of chance findings from multiple comparisons. The active arm sample size was moderate rather than large for detecting modest effects.