Effects of prenatal food and micronutrient supplementation on child growth from birth to 54 months of age: a randomized trial in Bangladesh

Setting: Matlab, rural Bangladesh. Participants: 4436 pregnant women enrolled between Nov 2001 and Oct 2003; eligibility included viable fetus, gestational age <14 weeks, no severe illness, informed consent. Design: randomized, factorial trial with six groups (early vs usual food invitation; Fe30F, Fe60F, or MMS). Micronutrient supplementation delivered as capsules; food invitation not masked. Offspring followed from birth to 54 months; 3267 births with birth anthropometry and 2735 children analyzed at 54 months.

Food supplementation: Prenatal energy-protein supplement totaling 608 kcal/day containing 80 g roasted rice powder, 40 g roasted pulse powder, 20 g molasses, and 12 mL soybean oil; taken with water; provided 6 days per week and continued through pregnancy; timing varied by group: early invitation immediately after pregnancy identification or usual invitation in the second trimester. Micronutrient supplementation: Daily capsules started around 14 weeks gestation according to one of three regimens: Fe30F (30 mg iron as fumarate + 400 μg folic acid), Fe60F (60 mg iron + 400 μg folic acid), or MMS (15 micronutrients including 30 mg iron and 400 μg folic acid). MMS capsules contain 150 μg iodine, 15 mg zinc, 65 μg selenium, 2 mg copper, 800 μg retinyl acetate, B vitamins, 30 mg iron, 400 μg folic acid, and other micronutrients; bottles contained 35 capsules and were delivered during monthly home visits; initiation around 14 weeks gestation and continued to the end of pregnancy.

Early invitation to prenatal food supplementation reduced stunting in boys from birth to 54 months (average across 16 measurements: 4.5 percentage-point reduction; 95% CI 1.2 to 7.8; p=0.01); effect not observed in girls (p=0.31). Prenatal MMS increased stunting vs Fe60F (average difference 4.8 percentage points; 95% CI 0.8 to 8.9; p=0.02). There was no interaction between food timing and micronutrient type on growth. Conclusion: Starting prenatal food supplementation early reduces child stunting in boys, suggesting programming effects in early fetal life; prenatal MMS increased stunting in boys and did not improve overall postnatal growth. Implications for public health include considering early food supplementation in pregnancy and cautious interpretation of MMS as a growth-promoting prenatal strategy in this setting.

Attrition with substantial losses to follow-up; data imputation used for missing measurements; not designed to assess risks of excess micronutrient supplementation or interactions between micronutrients; food supplementation was not masked; findings from a single rural Bangladeshi population may limit generalizability.