A randomized controlled trial in Nepal suggested that supplementation with vitamin A or beta carotene before, during, and after pregnancy reduced maternal deaths by over 40% in a population of rural women with severe vitamin A deficiency. However, 2 trials in similar populations, one in Bangladesh and the other in Indonesia, reported no benefit of vitamin A supplementation on maternal death rates.
The primary aim of the ObaapaVitA, a cluster-randomized, double-blind, placebo-controlled trial, was to investigate the effect of vitamin A supplementation in women of reproductive age on pregnancy-related mortality and all-cause female mortality. The investigators hoped to show similar benefits of supplementation among a population of severely vitamin A deficient pregnant women to those reported in the Nepal trial. The trial was conducted in 7 districts in the Brong Ahafo Region in Ghana. The trial area was divided into 1086 clusters of compounds, with fieldworkers responsible for 4 contiguous clusters. Participants were all women aged 15 to 45 years who planned to remain in the area for at least 3 months. The study subjects were randomly assigned, according to their cluster of residence, to receive 1 capsule weekly of either a vitamin A (n = 104,484, 544 clusters) or placebo (n = 104,484, 544 clusters). Randomization by cluster minimized the risk of women receiving the wrong capsules. Fieldworkers visited the women at home every 4 weeks, and distributed capsules and collected data on pregnancies, births, deaths, migrations, hospital admissions, and postpartum morbidity. Verbal postmortems with close relatives or friends established the cause of death. Random-effects regression and intention-to-treat analyses defined by cluster of residence were used to compare treatment groups. The primary reason for study drop outs was migration out of the study area.
There were no significant differences in the rate of pregnancy-related deaths among the groups (vitamin A supplementation group: 138 deaths [348 deaths per 100,000 pregnancies] versus the placebo group: 148 deaths [377 per 100,000 pregnancies) (adjusted odds ratio, 0.92; 95% confidence interval, 0.73–1.17; P = 0.51). A total of 1326 women died of any cause in the vitamin A supplementation group (453 deaths per 100,000 years) compared with 1298 in the placebo group (449 per 100,000 years) (adjusted odds ratio, 1.01; 95% confidence interval, 0.93–1.09; P = 0.85). No differences were found between the groups in rates of pregnancy-related hospital admissions or stillbirths, or in perinatal, neonatal, or infant survival.