Dietary quality during pregnancy varies by maternal characteristics in Project Viva: a US cohort

Maternal diet may influence outcomes of pregnancy and childhood, but data on correlates of food and nutrient intake during pregnancy are scarce.

To examine relationships between maternal characteristics and diet quality during the first trimester of pregnancy. Secondarily we examined associations of diet quality with pregnancy outcomes.

As part of the ongoing US prospective cohort study Project Viva, we studied 1,777 women who completed a food frequency questionnaire during the first trimester of pregnancy. We used linear regression models to examine the relationships of maternal age, prepregnancy body mass index, parity, education, and race/ethnicity with dietary intake during pregnancy. We used the Alternate Healthy Eating Index, slightly modified for pregnancy (AHEI-P), to measure diet quality on a 90-point scale with each of the following nine components contributing 10 possible points: vegetables, fruit, ratio of white to red meat, fiber, trans fat, ratio of polyunsaturated to saturated fatty acids, and folate, calcium, and iron from foods.

Mean AHEI-P score was 61+/-10 (minimum 33, maximum 89). After adjusting for all characteristics simultaneously, participants who were older (1.3 points per 5 years, 95% confidence interval [CI] [0.7 to 1.8]) had better AHEI-P scores. Participants who had higher body mass index (-0.9 points per 5 kg/m(2), 95% CI [-1.3 to -0.4]), were less educated (-5.2 points for high school or less vs college graduate, 95% CI [-7.0 to -3.5]), and had more children (-1.5 points per child, 95% CI [-2.2 to -0.8]) had worse AHEI-P scores, but African-American and white participants had similar AHEI-P scores (1.3 points for African American vs white, 95% CI [-0.2 to 2.8]). Using multivariate adjusted models, each five points of first trimester AHEI-P was associated lower screening blood glucose level (beta -.64 [95% CI -0.02 to -1.25]). In addition, each five points of second trimester AHEI-P was associated with a slightly lower risk of developing preeclampsia (odds ratio 0.87 [95% CI 0.76 to 1.00]), but we did not observe this association with first trimester AHEI-P (odds ratio 0.96 [95% CI 0.84 to 1.10]).

Pregnant women who were younger, less educated, had more children, and who had higher prepregnancy body mass index had poorer-quality diets. These results could be used to tailor nutrition education messages to pregnant women to avoid long-term sequelae from suboptimal maternal nutrition.