The consumption of ultra-processed foods has increased in recent decades and is associated with negative health outcomes. During pregnancy, inadequate nutrition can compromise both the mother's health and fetal development, which makes it important to investigate the factors associated with the consumption of these foods by pregnant women, especially those treated in the public health system, a group often exposed to greater social and nutritional vulnerability. The study aims to estimate the prevalence of consumption of ultra-processed foods and its association with sociodemographic, clinical, obstetric and nutritional characteristics among pregnant women assisted in the public health network. This is an epidemiological, cross-sectional and analytical study carried out with 1279 pregnant women between 2018 and 2019. The Food Consumption Frequency Questionnaire was used to verify the consumption of ultra-processed foods, being associated with sociodemographic, obstetric, clinical and nutritional characteristics. during pregnancy, based on the NOVA classification. Poisson regression models were used to describe the crude and adjusted associations of high consumption of ultra-processed foods (scores ≥5) with the other study variables. The prevalence of high consumption of ultra-processed foods was 78.3%. After adjustments, associations of this consumption with the following characteristics were observed: 1) distal level: being between the age groups of up to 20 years (PR = 1.26; p < 0.001) and 21 to 30 years (PR = 1, 14; p = 0.001), have an income of less than 1 minimum wage, equivalent to R$976.00 (PR = 0.89; p = 0.005); 2)intermediate level: not having arterial hypertension (PR = 1.40; p = 0.024), nor diabetes mellitus (PR = 1.32; p = 0.009), and presenting depressive symptoms (PR = 1.06; p = 0.050); 3) proximal level: not having been on a diet during pregnancy (PR = 1.33; p = 0.001) and eating less than 3 meals a day (PR = 1.14; p = 0.029). In conclusion, a high prevalence of pregnant women consuming ultra-processed foods was evidenced in the present study, associated with sociodemographic, clinical and nutritional characteristics.

Keywords: Pregnancy; eating; food, processed; industrialized foods; primary health care.