Assessment of Minimum Dietary Diversity for Women (MDD-W) as a proxy of dietary micronutrient adequacy among pregnant women in low- and middle-income countries

Nutritional needs of women increase during pregnancy. So far, no indicator has been validated to assess whether pregnant women reach sufficient dietary diversity to fill their needs. Building on the Minimum Dietary Diversity for Women (MDD-W) indicator used for non-pregnant women, this study aimed to determine the minimum number of food groups, out of the 10 used in MDD-W, necessary to ensure sufficient micronutrient intake among pregnant women.
By analysing secondary dietary data from 6 surveys conducted in 4 low and middle income countries, researchers identified the threshold of food groups that could reliably indicate micronutrient adequacy for pregnant women, following the same methodology used to validate MDD-W. The findings show that the MDD-W indicator can effectively be applied to pregnant women, indicating that its guidelines are valid for all women of reproductive age, whether pregnant or not.

The MDD-W indicator has been widely adopted by international programmes as an estimate of micronutrients adequacy among women of reproductive age, at population level. However, this indicator has not been validated for pregnant and lactating women, who face additional nutritional needs. With the idea to make the MDD-W indicator more universal, the European Union requested the NRF to assess its validity among pregnant women, using existing data.

The authors used secondary quantitative 24-h recall data from 6 surveys in 4 LMICs (Bangladesh, Burkina Faso, India, and Nepal, total 4909 pregnant women). They computed the 10-food group Women’s Dietary Diversity Score (WDDS-10) and calculated the mean probability of adequacy (MPA) of 11 micronutrients. Linear regression models were fitted to assess the associations between WDDS-10 and MPA. Sensitivity, specificity, and proportion of individuals correctly classified were used to assess the performance of MDD-W in predicting an MPA of >0.60.

In the pooled sample, median values (interquartile range) of WDDS-10 and MPA were 3 (1) and 0.20 (0.34), respectively, whereas the proportion of pregnant women with an MPA of >0.60 was 9.6%. The WDDS-10 was significantly positively associated with MPA in each survey. Although the acceptable food group consumption threshold varied between 4 and 6 food groups across surveys, the threshold of 5 showed the highest performance in the pooled sample with good sensitivity (62%), very good specificity (81%), and percentage of correctly classified individuals (79%).

The WDDS-10 is a good predictor of dietary micronutrient adequacy among pregnant women aged 15–49 y in LMICs. Moreover, the threshold of 5 or more food groups for the MDD-W indicator may be extended to all women of reproductive age, regardless of their physiologic status.

Given the limited number of settings and participants analysed, additional studies are needed to confirm these findings in other contexts and countries. This will strengthen the validity of these nutritional recommendations for all women of reproductive age.

Dietary diversity is a major determinant of health. For pregnant women especially, dietary diversity impacts not only women’s health but also birth outcomes and child’s health. Having a universal indicator will help better evaluating the efficiency of programmes aiming at increasing women’s dietary diversity and improving populations’ health status.

Main contact: Eric Verger

Organisation: IRD

Email address: eric.verger@ird.fr