Adherence and costs of micronutrient supplementation in pregnancy in a double-blind, randomized, controlled trial in rural western China

Abstract

Background: Efforts to determine the impact of prenatal multivitamin supplementation on birth outcome have been carried out in several developing countries. A review of factors that would impact the effectiveness of prenatal supplementation under normal field conditions is currently lacking and will be required for expanded supplementation programs. An efficacy trial of a multiple micronutrient supplement for pregnant women was conducted in rural western China, and additional information on side effects, rates of adherence, program inputs, and cost was also gathered.

Objectives: To examine reports of side effects and rates of adherence to prenatal multiple micronutrient supplementation in comparison with supplementation with folic acid and with iron-folic acid, and to describe inputs and costs associated with prenatal supplementation in China.

Methods: A cluster-randomized, double-blind, controlled trial was conducted in two rural counties in northwest China. All pregnant women in villages were randomly assigned to take daily supplements of folic acid, iron-folic acid, or a recommended daily allowance of 15 vitamins and minerals from enrollment until delivery. Information was collected from the women on side effects and adherence. Program inputs and costs of supplementation were tracked. Descriptive statistics were used for the analysis. The biological effectiveness of prenatal multiple micronutrient supplements is reported elsewhere.

Results: Less than 4% of women withdrew from the study because of side effects. Adherence to supplementation was high: the supplements were consumed on more than 90% of the days on which they were available for consumption. The mean number of supplements consumed was high at 165 capsules, and about 40% consumed the recommended 180 supplements during pregnancy.

Conclusions: High adherence to a prenatal supplement schedule can be achieved when mothers have frequent contact with trained health workers and a reliable supply of supplements.