A cluster randomized trial to demonstrate the equivalency of lower dose calcium supplementation during pregnancy for reducing preeclampsia and preterm birth

This is a trial-based study funded by the Bill and Melinda Gates Foundation. It intends to generate evidence for decision-making on the potential non-inferiority of a lower dose of calcium in preventing preeclampsia and preterm birth. The study also seeks to understand the accessibility, uptake and adherence to the WHO recommended 1500mg calcium supplementation among pregnant women in Tanzania.During trials planned to last 42 months, researchers will administer a lower dose of calcium supplements – only 500mg instead of 1500mg recommended by the WHO – hoping that it would do the job done by the full dose.

The overall aim of the initiative is cutting down the cost from approximately TZS 1500 to only TZS 500 per day and reducing the burden of taking more pills. The study is being undertaken parallel in India and Tanzania by ARCAD, Muhimbili University of Health and Allied Sciences (Muhas), Harvard University, Africa Academy for Public Health and St. John’s Research Institute.

The objective of this study is to generate causal evidence for decision-making on the potential non-inferiority of a lower dose of calcium in preventing preeclampsia and preterm birth and to understand the acceptability, uptake, and adherence to the WHO recommended 1500 mg calcium supplementation among pregnant women in Tanzania and India. Specific aims:

I) Determine if a daily 500mg calcium supplement regimen provides an unacceptably inferior effect on the incidence of preeclampsia than a daily 1500mg calcium supplement regimen among pregnant women in Tanzania.

II) Determine if a daily 500mg calcium supplement regimen provides an unacceptably inferior effect on preterm birth than a daily 1500mg calcium supplement regimen among pregnant women in Tanzania.

III) Assess the facilitators, enablers, and barriers to implementation of a 1500mg calcium supplement regimen from the perspective of pregnant women and healthcare providers in Tanzanian settings.

Methods We will conduct two, parallel individually randomized, double blind trials in Bangalore, India and Dar es Salaam, Tanzania. Each woman will be randomized to either standard dose (1500 mg) or low dose (500 mg) calcium supplementation.

The primary outcomes of the study are:

i) preeclampsia.

 ii) preterm birth.

A parallel, mixed-methods implementation cohort study will also be conducted at one additional health facility in each country to assess the barriers and enablers of health system implementation and individual acceptability and compliance of the WHO-recommended 1500 mg calcium supplementation regimen.#