The effect of motivational interviewing and/or cognitive behaviour therapy on gestational weight gain – a systematic review and meta-analysis

Background: Women with insufficient or excessive weight gain in pregnancy are at risk of adverse perinatal outcomes. Motivational interviewing and/or cognitive behaviour therapy have demonstrated efficacy in initiating and sustaining behaviour change, including weight control. The objective of this review was to investigate the effect of antenatal interventions that include components of motivational interviewing and/or cognitive behaviour therapy on gestational weight gain. Methods Five electronic databases were systematically searched to March 2022. Randomised controlled trials evaluating interventions with identified components of motivational interviewing and/or cognitive behaviour therapies were included. Pooled proportions of appropriate and inappropriate gestational weight gain, and standardised mean difference for total gestational weight gain, were calculated. Grades of Recommendation, Assessment, Development and Evaluation approach was used to evaluate the quality of evidence. Results Twenty-one studies (8030 participants) were included. Overall, the intervention limited total gestational weight gain (-0.18 kg, 95% confidence interval: -0.27 to -0.09 kg) and improved the proportion of women achieving recommended gestational weight gain (29% versus 23%, p < 0.001), but the evidence is very uncertain. The magnitude of effect was greater in women with overweight or obesity when compared to women with BMI < 25 kg/m 2 . Conclusion Motivational interviewing and/or cognitive behaviour therapy techniques might be effective for promoting healthy gestational weight gain. Nevertheless, a high proportion of women do not achieve recommended gestational weight gain. Future interventions should consider factors, including user perspectives, in the design and delivery of psychosocial interventions that aim to support healthy gestational weight gain. Study registration: The protocol for this review was registered with the PROSPERO International register of systematic reviews (registration number CRD 42020156401).