Quality of diet during pregnancy and its association with birth weight

The quality of the diet of pregnant women is associated with several effects on maternal and fetal health. The Adapted Diet Quality Index for Pregnant Women (IQDAG), developed for Brazilian pregnant women, has nine components: vegetables, legumes and fresh fruits in portions/1000 kcal; iron, folate, calcium, omega 3 and fibers, and as a moderating component the energy percentage from the consumption of ultra-processed foods. The aim of the present study was to investigate the relationship between IQDAG and birth weight. This is a prospective cohort. Between 2011 and 2012, 783 pregnant women attended by the Unified Health System (SUS) in Ribeirão Preto, SP, were interviewed between the 24th and 39th gestational weeks. Women aged &ge; 20 years, pre-gestational BMI &ge; 20 kg/m2, absence of previous diabetes, with no use of glucocorticoids or diseases that alter food consumption were included. Secondary data of the newborns were obtained from the Live Birth Information System (SINASC). Cases of gestational diabetes mellitus, twinning, gestational week at delivery> 42 and incomplete data were excluded, totaling 601 mother-baby binomials. Birth weight was classified as low birth weight (LBW) (<2500g) and macrosomia (&ge; 4000g). Babies were classified as small for gestational age (SGA) or large for gestational age (SGA) using Intergrowth curves. The diet was estimated by two 24-hour recall surveys, collected between the 24th and 39th gestational weeks, and a food frequency questionnaire, referring to the gestational period. The usual intake was obtained using the Multiple Source Method. The relationship between the IQDAG score and birth weight was investigated in backward binary logistic regression models adjusted for sex of the baby, gestational week at delivery, mode of delivery, maternal age, maternal height, skin color classification, education, social class, smoking, physical activity, high blood pressure, pre-gestational BMI, average weekly weight gain, parity, total diet energy and energy underreporting. Data analyses were performed using the SPSS software and the significance level adopted was p <0.05. The mean (SD) age of the pregnant women was 27.2 years (5.3) and the mean score (SD) of the IQDAG was 69.7 points (11.9). Overall, 6.3% of the newborns were classified as having LBW, 5.5% as macrosomia, 10.3% SGA and 13.3% LGA. Adjusted logistic regression models showed a lower LGA trend in babies of women in the third tertile of the IQDAG score [OR 0.53 (95% CI 0.28; 1.00), P- trend = 0.05] compared to the first tertile. Pregnant women in the third tertile of omega 3 intake were less likely to have LGA babies [OR 0.43 (95% CI 0.23; 0.82), P-trend = 0.01] compared to those in the first tertile. Pregnant women in the third tertile of iron intake were less likely to have children with LBW [OR 0.33 (95% CI 0.12; 0.87), P-trend = 0.01] compared to those in the first tertile. The data suggest that a better diet quality, assessed by IQDAG, and higher intake of omega 3 during pregnancy are protective factors for GIG and a higher maternal intake of iron may reduce the chance of LBW. (AU)