Adherence to physical activity during the first trimester of pregnancy: a study from Southern Italy

Background: Although international recommendations strongly support regular physical activity during pregnancy due to the improved maternal and fetal outcomes, adherence to physical activity remains low, particularly in early gestation. Understanding activity patterns during the first trimester is crucial, as behaviors established in this phase often persist throughout pregnancy. Objectives: To describe physical activity levels and adherence to international recommendations among low-risk pregnant women in the first trimester, using the Italian version of the Pregnancy Physical Activity Questionnaire (PPAQ). Study design: This cross-sectional observational study includes 498 low-risk singleton pregnant women between 11+3 and 13+6 weeks' gestation, recruited at the University Hospital of Naples Federico II, Italy, between January 2022 and December 2023. Participants completed the Italian version of the PPAQ. Total energy expenditure was expressed in MET-h/week, and women were classified as exercisers (≥ 150 mines/week of moderate-intensity activity) or non-exercisers. Results: Participants reported a median of 11.5 (IQR 8.2-15.0) h/week of total activity, corresponding to 155.7 (102.6-241.7) METs-h/week. While 51% met the threshold of ≥ 150 min/week of moderate-intensity activity when considering all activity domains, only 7.8% reached this target through sport or structured exercise alone. Walking represented the most common exercise (64.1% slow, 46.2% brisk, 25.6% uphill). Employment status was significantly associated with higher adherence to recommendations, whereas other sociodemographic factors showed no significant differences. Conclusions: Structured exercise should be improved in the daily routine to optimize maternal and fetal health, although activity levels may appear adequate. Adherence to physical activity recommendations could be promoted by integrating validated tools such as the PPAQ into routine prenatal care and targeted interventions.