Physical activity before and during pregnancy and maternal mental health: A systematic review and meta-analysis of observational studies.

Objective: To examine the influence of physical activity before and during pregnancy on maternal mental health outcomes.

Methods: Ten electronic databases were searched up to May 11, 2021. Studies of all observational designs (except case studies and reviews) were included, which contained information on the relevant population (women before and or during pregnancy), exposures (objective or subjective measures of physical activity), comparator (low or no physical activity), and outcomes (diagnosis and symptom severity of depression or anxiety, quality of life scores, stress and emotions).

Results: Forty-four observational studies (N = 132,399) were included. 'Low' to 'very low' certainty evidence revealed that compared with low levels of PA during pregnancy, high levels of PA were associated with a reduced odds of developing prenatal depression (odds ratio (OR): 0.68, 95% confidence interval (CI): 0.58 to 0.80) and anxiety (OR: 0.67, 95% CI: 0.54 to 0.83). We also found a reduction in the severity of prenatal depressive symptoms (standardized mean difference (SMD): -0.37, 95% CI -0.57 to -0.17), prenatal anxiety symptoms (SMD: -0.45, 95% CI -0.64 to -0.27), and prenatal stress (SMD: -0.33, 95% CI -0.55 to -0.11), concurrent with improved quality of life (SMD: 0.38, 95% CI 0.23 to 0.54). PA before pregnancy did not impact the outcomes of interest.

Conclusion: Physical activity during pregnancy is associated with a reduction in the odds and severity of prenatal depression and anxiety, as well as reduced stress and improved quality of life. PROSPERO registration number: CRD42020208469.