Trial participants
From August 2016–September 2018, 714 pregnant women were assessed for
eligibility. A total of 67 women did not receive information about the
study and 647 were initially invited to participate. A total of 282
women were randomly assigned to either supervised group exercise (n=143)
or the control group (n=139) (Figure 1). Eight women from the
intervention group withdrew consent: one found the exercise
uncomfortable to perform, two preferred other kinds of physical activity
and five women could not find the time to participate.
Baseline maternal characteristics in the intervention group and the
control group were comparable (Table 1).
The study population´s mean age was 31.8 years (SD 3.9), 73.4% were
nulliparous, the mean pre-pregnancy body mass index was 22.8
kg/m2 (SD 3.5), 87% had a higher education or
advanced degree, 99% did not smoke at baseline and 78% of the study
population were physically active ≥3.5 hours a week before pregnancy.
The median weekly amount of physical activity was measured after the
intervention and eight weeks postpartum: 4 hours (min 0–max 24) in the
intervention group and 4 hours (min 0–max 16) in the control group at
29–34 weeks of gestation, 6 hours (min 0–max 25) in the intervention
group and 6 hours (min 0–max 25) in the control group eight weeks
postpartum.
A total of 127 (95%) participants in the intervention group and 118
(86%) in the control group responded to the self-administered
questionnaire at 29–34 weeks of gestation, while 99 (74%) participants
in the intervention group and 84 (61%) in the control group responded
eight weeks postpartum (Figure 1).