Effectiveness of physical activity interventions for overweight and obesity during pregnancy: a systematic review of the content of behaviour change interventions.

BACKGROUND: Behaviour change techniques (BCTs) employed within PA intervention for pregnant women with a healthy body mass index (BMI) have been previously identified, however, these BCTS may differ for other weight profiles during pregnancy. The aim of this current review was to identify and summarise the evidence for effectiveness of PA interventions on PA levels for pregnant women with overweight and obesity, with an emphasis on the BCTs employed. METHODS: A systematic review and meta-analysis of PA intervention studies using the PRISMA statement was conducted. Searches were conducted of eight databases in January 2019. Strict inclusion/exclusion criteria were employed. The validity of each included study was assessed using the Cochrane Collaboration's tool for assessing risk of bias. The primary outcome measure was change in PA levels, subjectively or objectively measured, with physical fitness as a secondary outcome. All intervention descriptions were double coded by two authors using Michie's et al's BCT taxonomy V1. Meta-analyses using random effect models assessed the intervention effects on PA. Other PA outcomes were summarised in a narrative synthesis. RESULTS: From 8389 studies, 19 met the inclusion criteria 13 of which were suitable for inclusion in a meta-analysis. The remaining 6 studies were described narratively due to insufficient data and different outcome measures reported. In the meta-analysis, comparing interventions to a control group, significant increases were found in the intervention group for metabolic equivalent (SMD 0.39 [0.14, 0.64], Z = 3.08 P = 0.002) and physical fitness (VO2 max) (SMD 0.55 [0.34, 0.75], Z = 5.20 P = < 0.001). Of the other six, five studies reported an increase in PA for the intervention group versus the control with the other study reporting a significant decrease for women in their 3rd trimester (p = 0.002). 'Self-monitoring of behaviour' was the most frequently used BCTs (76.5%), with 'social support' being newly identified for this pregnant population with overweight or obesity. CONCLUSIONS: This review identified a slight increase in PA for pregnant women with overweight and obesity participating in interventions. However, due to the high risk of bias of the included studies, the results should be interpreted with caution. PA measures should be carefully selected so that studies can be meaningfully compared and standardised taxonomies should be used so that BCTs can be accurately assessed.

Social, biological, behavioural and psychological factors related to physical activity during early pregnancy in the Screening for Pregnancy Endpoints (Cork, Ireland) cohort study.

OBJECTIVE: The aim of this study was to identify the social, biological, behavioural and psychological factors related to physical activity (PA) in early pregnancy. DESIGN: This is a secondary analysis of data from a prospective cohort study. SETTING: The study was conducted in Cork, Ireland. PARTICIPANTS: Nulliparous women with singleton pregnancies were recruited and then interviewed at 15±1 weeks' gestation. PRIMARY AND SECONDARY OUTCOMES: The biopsychosocial model identified factors including social (age), biological (body mass index), behavioural (diet) and psychological (anxiety) at 15±1 weeks' gestation. PA subgroups were identified based on a latent class analysis of their responses to a set of questions about the amount and intensity of activity they were engaging in during the pregnancy. Associations were estimated with multivariable multinomial logistic regression models. RESULTS: From a total of 2579, 1774 (69%) women were recruited; ages ranged from 17 to 45 years. Based on a combination of model fit, theoretical interpretability and classification quality, the latent class analyses identified three PA subgroups: low PA (n=393), moderate PA (n=960) and high PA (n=413). The fully adjusted model suggests non-smokers, and consumers of fruit and vegetables were more likely to be in the high PA subgroup (vs low). Women with more than 12 years of schooling and a higher socioeconomic status were more likely to be in the moderate PA subgroup (vs low). CONCLUSION: The findings highlight potential links between PA, a low education level and a low socioeconomic background. These factors should be considered for future interventions to improve low PA levels during pregnancy. TRIAL REGISTRATION NUMBER: ACTRN 12607000551493.