Daily antenatal MM versus IFA supplements in the JiVitA-3 cluster-randomized trial reduced preterm and low birth weight among n=28,516 births in rural Bangladesh. Whether this beneficial impact was mediated by improved fetal micronutrient status has not been explored. We demonstrate the effect of MM versus IFA on newborn micronutrient status indicators in cord blood, and associations of cord and maternal indicators as a proxy for micronutrient transfer to the fetus.
Cord blood plasma obtained from n=338 home deliveries, and corresponding maternal plasma samples from 32 weeks of gestation, were assessed for ferritin (iron status), folate, vitamin B12, 25-hydroxyvitamin D (25(OH)D, vitamin D status), zinc, thyroglobulin (iodine status), and a-1 acid glycoprotein (AGP, inflammation). Intervention effects and associations of maternal and cord indicators were explored, accounting for cluster randomization.
Cord ferritin, zinc, and 25(OH)D were higher in the MM vs IFA group, while folate was lower (all p<0.05). However, cord folate and 25(OH)D were more strongly positively associated with maternal third trimester concentrations, as were vitamin B12 and thyroglobulin (all p<0.01). Overall, ferritin, folate, vitamin B12, zinc, and thyroglobulin concentrations were 1.5-6.6 times higher in cord than in maternal plasma; 25(OH)D and AGP were 0.8 and 0.4 times as high, respectively.
Higher cord than maternal ferritin, folate, vitamin B12, and zinc is consistent with active placental micronutrient transport, with lower 25(OH)D consistent with passive transport. Higher cord thyroglobulin could reflect fetal iodine demand, and lower cord AGP protection from inflammation. Fetal micronutrient status was associated with either or both maternal status and antenatal MM supplementation.