This is a plain English summary of an original research article
For women who have had a baby in the past year, doing aerobic exercise can reduce the level of depressive symptoms they experience.
This NIHR funded review of 13 studies showed that involving new mothers in group exercise programmes, or advising them on an exercise of their choice, reduced depressive symptoms compared with usual care. The effect was moderate but significant. Examples of exercise were pram walks, with dietary advice from peers in some studies. The benefits were shown whether or not the mothers had postnatal depression.
This evidence does have some limitations regarding its quality but is the best research currently available. This review should give additional confidence to health visitors and GPs to advise women that keeping active after birth can benefit their mental and physical health.
Why was this study needed?
Postnatal depression is a common condition, affecting about 10 to 15 in every 100 new mums in the UK.
Psychological treatments and antidepressants are options for the treatment of postnatal depression. However, some women may be concerned about taking antidepressants, especially if they are breastfeeding. Also, access to psychological treatments may be limited.
Group exercise programmes have been recommended by NICE for persistent subthreshold depression or mild to moderate depression in adults. This recommendation has not been explicitly made for postnatal depression. There may be practical, physical, or psychological barriers to new mums exercising.
This study aimed to assess the effect of exercise on depressive symptoms for women in the first year after they gave birth. It also looked at how characteristics of the participants or the exercise programmes impacted the studies’ results.
What did this study do?
This systematic review pooled 13 randomised controlled trials (with 1,734 women) mainly from the USA, UK and Australia. Seven trials included new mothers with a diagnosis of depression or depressive symptoms. The others included any new mothers.
Seven studies compared exercise counselling to equip women with the skills and confidence to increase exercise, with usual care or general education and support. Six used group exercise programmes, such as pram walking. The interventions aimed for 30 minutes of aerobic exercise three to five times weekly. Some interventions included other lifestyle advice, social support, or education. The interventions lasted from one to six months.
About half of the trials had a high risk of bias, because of the selective exclusion of some participants, and insufficiently robust generation of the randomisation sequence. This may mean an over-estimation of the impact of exercise. Also, the trials were not very similar, and symptoms were recorded in different ways, so the pooled results should be viewed with caution.
What did it find?
An average of six months after the start of the trials:
- Overall, exercise led to a small to moderate reduction in depressive symptoms in new mothers in the year after birth (standardised mean difference [SMD] ‑0.44, 95% confidence interval [CI] ‑0.75 to ‑0.12; 13 trials, 1,307 women). In the trials using the Edinburgh Postnatal Depression Scale, exercise improved depressive symptoms by 1.5 points more than usual care on a scale of 0 to 30 (weighted mean difference ‑1.54, 95% CI ‑2.97 to ‑0.12; 10 trials, 652 women).
- In mothers with known or suspected postnatal depression, exercise had a small to moderate effect on symptoms (SMD ‑0.32, 95% CI ‑0.63 to 0.00; 7 trials, 416 women). It was also moderately effective for the broader groups of new mothers with or without depression (SMD ‑0.57, 95% CI ‑1.12 to ‑0.02; 6 trials, 891 women).
- Both group exercise programmes, and exercise counselling programmes where mothers chose their exercise reduced depressive symptoms. The effect from the group exercise programmes was larger (SMD ‑1.10, 95% CI ‑1.99 to ‑0.21; 6 trials, 406 women) than for exercise counselling (SMD ‑0.20, 95% CI ‑0.33 to ‑0.06; 7 trials, 901 women), though the difference between the interventions was not statistically significant.
- Interventions which combined exercise with other lifestyle interventions such as social support were effective (SMD ‑0.35, 95% CI ‑0.66 to ‑0.04; 5 trials, 779 women). Exercise alone showed a trend towards being effective but did not reach statistical significance (SMD ‑0.57, 95% CI ‑1.13 to +0.01; 8 trials, 528 women).
What does current guidance say on this issue?
SIGN recommends moderate exercise three or more times a week as an option for postnatal depression.
Regular exercise is recommended by the Royal College of Psychiatrists as a self-help strategy for postnatal women who have low mood.
NICE 2014 guidance on mental health during and after pregnancy recommends self-help guided by a trained professional as an option for mothers who experience persistent depressive symptoms or have mild to moderate depression. More intense psychological treatments and drug treatment are options for moderate or severe postnatal depression. It does not provide advice about exercise.
More generally, NICE 2015 guidelines on postnatal care recommend gentle exercise as one of the ways new mothers should take care of themselves in the six to eight weeks following birth.
What are the implications?
New mothers may experience practical, physical and psychological barriers to exercise. Tailoring activity to the time they have available and any physical limitations may increase the chance of it being adopted.
The existing evidence does not yet tell us the optimal type or dose of exercise. However, pram walks as part of a group could offer both exercise and social support.
Information on antidepressant use or psychological therapy was not provided and we do not know the severity of depression in women in these studies.
Nevertheless, tailored exercise in addition to any other treatments is unlikely to cause harm and there are many additional benefits to exercise.
Citation and Funding
Pritchett R V, Daley A J, Jolly K. Does aerobic exercise reduce postpartum depressive symptoms? A systematic review and meta-analysis. British Journal of General Practice. 2017;67(663):e684-91.
This project was funded by the University of Bristol in conjunction with the National Institute for Health Research School for Primary Care Research and the Collaboration for Leadership in Applied Health Research and Care West Midlands.
NHS Choices. Postnatal depression. London: Department of Health; updated 2016.
NICE. Antenatal and postnatal mental health: clinical management and service guidance. CG192. London: National Institute for Health and Care Excellence; 2014, updated 2017.
NICE. Postnatal care up to 8 weeks after birth. CG37. London: National Institute for Health and Care Excellence; 2006, updated 2015.
NICE. Depression in adults: recognition and management. CG90. London: National Institute for Health and Care Excellence; 2009, updated 2016.
Royal College of Psychiatrists. Postnatal depression. London: Royal College of Psychiatrists; updated 2015.
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