Cross sectional analysis of dietary quality among pregnant women in central South Africa: The NuEMI study

Abstract

Background: During pregnancy, poor dietary quality is linked to maternal complications and poor birth outcomes, but no dietary quality index for pregnancy has been developed using African data. This study aimed to determine the diet quality of South African pregnant women by applying the Diet Quality Index Adapted for Pregnant Women (IQDAG), developed in Brazil, to data collected in the NuEMI (Nutritional status of Expectant Mothers and their newborn Infants) study.Methods: The NuEMI study applied a descriptive study design to collect data from 681 pregnant women visiting an antenatal clinic at a regional hospital in Mangaung, central South Africa. The IQDAG was applied to dietary data collected with a quantitative food frequency questionnaire during structured interviews. Energy and nutrient intakes were quantified with the South African Medical Research Council Food Composition Database. The Women’s Dietary Diversity Score (WDDS) was applied to 24h-recall data obtained during the interviews. Associations of IQDAG scores, nutrient intakes, sociodemographic variables, WDDS and birth anthropometry were explored by contingency tables.Results: Participants had a median age of 31.9 years (IQR: 26.8‒36.7) and a median pregnancy stage of 32.0 weeks (IQR: 26.0‒36.0). The median total dietary quality score (61/100; IQR:53‒68) indicated that most of these women had a suboptimal diet. Only 2.5% had a good dietary quality, reaching at least 80% of the maximum IQDAG score that represents the minimum pregnancy recommendations. The median intakes for none of the nine components of the IQDAQ met the recommendations. Fruit, vegetables, legume, dietary calcium and omega-3 intakes were particularly low, while the intake of ultra-processed foods was above optimal. Most participants consumed only half of the recommended amounts of iron and folate from their diets. IQDAG scores were significantly (p<0.0001) associated with the dietary intakes of most nutrients, even after correction for energy intakes, and with dietary diversity (p<0.0001) and length-for-age z scores at birth (p=0.01).Conclusions: Pregnant women In a South African public health setting had poor to suboptimum dietary quality. Improving the dietary quality of pregnant women in low to middle-income countries would reduce the high financial and human cost of poor birth outcomes and maternal complications. The results also emphasise the importance of prenatal micronutrient supplementation.