Iron and folic acid supplements in pregnancy are widely recommended. However, getting the supplements to the women and encouraging them to take them is particularly challenging. Micronutrient powders containing iron, vitamin A, zinc and other vitamins and minerals are usually packaged in single-use sachets and can be sprinkled onto any semi-solid food at home or in any other place where meals are to be consumed. The use of micronutrient powders to fortify foods may overcome this problem with micronutrient supplements. Micronutrient powders have already been shown to be effective in reducing anaemia and iron deficiency in young children and so may be useful for pregnant women.
This review looked at the use of micronutrient powders in pregnancy, compared with micronutrient supplements or with no additional micronutrients. We found only two studies involving a total of 1172 women, undertaken in Bangladesh and Mexico. The overall quality of evidence was judged very low (with a high risk of bias due to methodological limitations), and no evidence was available for the majority of primary and secondary outcomes of this review.
One trial compared micronutrient powders with iron and folate supplements, and the other trial compared micronutrient powders with the same nutrients but given as supplements. Overall, micronutrient powders fortification of foods had a similar effect as multiple micronutrient supplements on anaemia in mothers at or near term (very low quality evidence) or the mother's haemoglobin (Hb) at or near term. The study that compared micronutrient powders with iron and folic acid supplements reported that women were more likely to take iron and folic acid tablets than micronutrient powders. Nearly all of the review's important outcomes were not reported in the included studies. Therefore, more evidence is needed for both mother and infant health outcomes in order to adequately evaluate the use of micronutrient powders in pregnant women.
Authors' conclusions:
Limited evidence suggests that micronutrient powders for point-of-use fortification of foods have no clear difference as multiple micronutrient supplements on maternal anaemia (very low quality evidence) and Hb at or near term. There is limited evidence to suggest that women were more likely to adhere to taking tablets than using micronutrient powders.
The overall quality of evidence was judged very low (due to methodological limitations), and no evidence was available for the majority of primary and secondary outcomes. Therefore, more evidence is needed to assess the potential benefits or harms of the use of micronutrient powders in pregnant women on maternal and infant health outcomes. Future trials should also assess adherence to micronutrient powders and be adequately powered to evaluate the effects on birth outcomes and morbidity.