ABSTRACT
BACKGROUND: Physical activity (PA) at moderate intensity is recommended for healthy pregnant women. The three-arm FitMum randomised controlled trial showed that it was possible to increase PA level during pregnancy with structured supervised exercise training (EXE) compared to standard care. Motivational counselling on PA (MOT) did not increase PA. This process evaluation aims to understand the implementation and mechanisms of impact of EXE and MOT. METHODS: A mixed methods process evaluation was conducted using the UK Medical Research Council's process evaluation framework by assessing implementation (reach, fidelity, and dose) and mechanisms of impact of the two interventions provided to pregnant women in FitMum. Data was collected both quantitatively (n = 220) and qualitatively (n = 20). RESULTS: The FitMum trial reached educated pregnant women (80% having an educational level ≥ bachelor's degree) with high autonomy of everyday life. Most participants (58%) were recruited at their first-trimester ultrasonic scan. Reasons to participate were personal (91%) and altruistic (56%). The intervention dose was delivered as intended with high fidelity in the original physical intervention setup and in the altered online setup during the COVID-19 restrictions. A low dose received in EXE (1.3 [95% CI, 1.1; 1.5] sessions/week) was partly explained by the pre-scheduled EXE sessions favouring participants with a flexible everyday life and a supportive social network. Dose received in EXE increased during online intervention delivery. Participants in MOT received 5.2 [4.7; 5.7] of 7 sessions. Mechanisms of impact comprised a perception of intervention commitment among participants in EXE due to the scheduled EXE sessions, whereas participants in MOT considered themselves as PA self-determined. PA was considered as constrained activities in EXE and included in daily activities in MOT. CONCLUSION: The FitMum interventions was delivered with high fidelity. During COVID-19, the dose received in EXE increased compared to the previous physical setup. Mechanisms of impact as commitment, perception of empowerment and perception of PA as well as the paradox between prioritising PA and family and the need of a flexible everyday life need to be considered when offering pregnant women PA interventions. Future interventions should consider a combination of physical and online exercise training for pregnant women.
ABSTRACT
BACKGROUND: Physical activity (PA) during pregnancy is an effective and safe way to improve maternal health in uncomplicated pregnancies. However, compliance with PA recommendations remains low among pregnant women. OBJECTIVE: The purpose of this study was to evaluate the effects of offering structured supervised exercise training (EXE) or motivational counseling on PA (MOT) during pregnancy on moderate-to-vigorous intensity physical activity (MVPA) level. Additionally, complementary measures of PA using the Pregnancy Physical Activity Questionnaire (PPAQ) and gold standard doubly labeled water (DLW) technique were investigated. The hypotheses were that both EXE and MOT would increase MVPA in pregnancy compared with standard care (CON) and that EXE would be more effective than MOT. In addition, the association between MVPA and the number of sessions attended was explored. METHODS: A randomized controlled trial included 220 healthy, inactive pregnant women with a median gestational age of 12.9 (IQR 9.4-13.9) weeks. A total of 219 women were randomized to CON (45/219), EXE (87/219), or MOT (87/219). The primary outcome was MVPA (minutes per week) from randomization to the 29th gestational week obtained by a wrist-worn commercial activity tracker (Vivosport, Garmin International). PA was measured by the activity tracker throughout pregnancy, PPAQ, and DLW. The primary outcome analysis was performed as an analysis of covariance model adjusting for baseline PA. RESULTS: The average MVPA (minutes per week) from randomization to the 29th gestational week was 33 (95% CI 18 to 47) in CON, 50 (95% CI 39 to 60) in EXE, and 40 (95% CI 30 to 51) in MOT. When adjusted for baseline MVPA, participants in EXE performed 20 (95% CI 4 to 36) minutes per week more MVPA than participants in CON (P=.02). MOT was not more effective than CON; EXE and MOT also did not differ. MVPA was positively associated with the number of exercise sessions attended in EXE from randomization to delivery (P=.04). Attendance was higher for online (due to COVID-19 restrictions) compared with physical exercise training (P=.03). Adverse events and serious adverse events did not differ between groups. CONCLUSIONS: Offering EXE was more effective than CON to increase MVPA among pregnant women, whereas offering MOT was not. MVPA in the intervention groups did not reach the recommended level in pregnancy. Changing the intervention to online due to COVID-19 restrictions did not affect MVPA level but increased exercise participation. TRIAL REGISTRATION: ClinicalTrials.gov NCT03679130; https://clinicaltrials.gov/ct2/show/NCT03679130. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.1136/bmjopen-2020-043671.