BACKGROUND: Exercise during pregnancy is associated with health benefits for both the mother and the fetus, and is therefore recommended in several national guidelines. Only few studies investigate whether these guideline recommendations are met. The aims of this study were 1. To assess the prevalence of pregnant women meeting the Danish recommendations for exercise during early pregnancy, 2. To identify pre-pregnancy factors associated with a lower probability for meeting the recommendations, and 3. To describe which types of exercise pregnant women prefer before and during pregnancy.

METHODS: We conducted a cross-sectional study based on a questionnaire during the first trimester among 7,915 women participating in the prospective Copenhagen Pregnancy Cohort. Associations were estimated by multivariate regression analyses.

RESULTS: In early pregnancy, 38 % of the study population met the recommendation for exercise from the Danish Health and Medicines Authority (≥3.5 hours a week). Multiparity, previous miscarriage use of assisted reproductive technology, no engagement in exercise before pregnancy, smoking, pregnancy following assisted reproductive technology, overweight, not understanding Danish language and a low educational level were all factors associated a lower probability for meeting the recommendations. The preferred types of exercise before and during pregnancy were bicycling, brisk walking, running and strength training. The proportion of women engaged in any type of exercise decreased in early pregnancy with the exception of swimming and aquatic exercise.

CONCLUSIONS: In this cohort, more than one-third met the Danish recommendation for exercise during early pregnancy. Exercise in pregnancy is still an issue to address because the most vulnerable groups of pregnant women do not exercise. This is a cause of concern because it may reflect social inequalities in health and highlights the need for a structural and systematic approach to preconception care and early antenatal counselling.