Combined food and micronutrient supplements during pregnancy have limited impact on child blood pressure and kidney function in rural Bangladesh

Abstract

Observational evidence suggests nutritional exposures during in utero development may have long-lasting consequences for health; data from interventions are scarce. Here, we present a trial follow-up study to assess the association between prenatal food and micronutrient supplementation and childhood blood pressure and kidney function. During the MINIMat Trial in rural Bangladesh, women were randomly assigned early in pregnancy to receive an early or later invitation to attend a food supplementation program and additionally to receive either iron and folate or multiple micronutrient tablets daily. The 3267 singleton birth individuals with measured anthropometry born during the trial were eligible for a follow-up study at 4.5 y old. A total of 77% of eligible individuals were recruited and blood pressure, kidney size by ultrasound, and glomerular filtration rate (GFR; calculated from plasma cystatin c) were assessed. In adjusted analysis, early invitation to food supplementation was associated with a 0.72-mm Hg [(95% CI: 0.16, 1.28); P = 0.01] lower childhood diastolic blood pressure and maternal MMS supplementation was associated with a marginally higher [0.87 mm Hg (95% CI: 0.18, 1.56); P = 0.01] childhood diastolic blood pressure. There was also some evidence that a supplement higher in iron was associated with a higher offspring GFR. No other effects of the food or micronutrient interventions were observed and there was no interaction between the interventions on the outcomes studied. These marginal associations and small effect sizes suggest limited public health importance in early childhood.

FIGURE 1

Flow diagram of offspring born during the MINIMat trial and those recruited into the current follow-up study. Diagram represents the flow of trial participants from enrollment through birth to the current follow-up at 4.5 y of age. All individuals who were live singleton births during the trial and for whom birth anthropometry was available were eligible for the current follow-up study. Details of loss to follow-up between randomization and birth can be found elsewhere (12). BP: number of individuals recruited for whom blood pressure was measured, mm Hg. Early food: maternal randomization to access food early in pregnancy. Kidney volume: number of individuals recruited for kidney size measurements by ultrasound, cm³/m². Preterm: individuals born before 37 wk of gestation were excluded at the analysis stage. Usual food: maternal randomization to access food at the usual time in pregnancy. CysC, number of individuals recruited for cystatin C measurements; Fe30F, 30 mg iron and 400 μg folate; Fe60F, 60 mg iron and 400 μg folate; MMS, multiple micronutrient supplement; Vol, volume.