Overview

Depressive disorders that may develop in a new mother have serious consequences, affecting both the mother's and the newborn’s health.

Mental and physical health are strongly connected indicating that mental health can be enhanced by improving physical health. Therefore, exercise may reduce the risk of postpartum depression.

What is postpartum depression?

Postpartum depression, also known as postnatal depression, is a period of depression that occurs after having a baby. It is very common, affecting 12-20% of new mothers.¹ This means that about 1 in 8 people who give birth may develop symptoms. Postpartum depression usually develops within one month after giving birth and can last up to 12 months. However, some of the symptoms may also begin during pregnancy.

During pregnancy and the postnatal period(during the first 6 weeks after giving birth), many changes occur in the mother’s body. These changes are both physical and mental/psychological. Experiencing childbirth and embracing the role of a new mother can be associated with various negative emotions such as anxiety, fear, sadness, uncertainty, disgust, or depression.²

The consequences of postpartum depression are serious affecting both the mother and the baby, as well as their relationship. Long-term consequences can also affect the infant’s health.

Signs and symptoms of postpartum depression

Depressive symptoms can be different for each person.

Symptoms of depression may include:

• A persistent feeling of sadness, anxiety, or emptiness
• Loss of interest in activities which were previously enjoyed
• Feelings of pessimism or hopelessness
• Feelings of helplessness, worthlessness, or guilt
• Feelings of irritability or restlessness
• Loss of energy
• Problems concentrating, making decisions, and recalling details
• Difficulty sleeping or sleeping too much
• Overeating or loss of appetite
• Thoughts of suicide

The symptoms of postpartum depression are similar to those of depression but may also include:

• Crying more often than usual
• Feeling angry
• Withdrawing from loved ones
• Feeling disconnected from your baby
• Feeling guilty about not being a good mother
• Doubting your ability to care for the baby
• Worrying about hurting the baby

Postpartum depression symptoms are individual; how often they occur, how long they last, and how intense they feel can be different for each person.³

Risk factors

Studies have revealed a number of risk factors that are strongly associated with postnatal depression. The most common risk factors that increase the chances of developing postnatal depression include:

• A history of depression in the past
• Depression or anxiety during pregnancy
• Stressful life events
• Low self-esteem
• Low social support or poor partner relations
• Low income
• Loneliness

Other reported risk factors include younger maternal age, fewer years of education, a history of miscarriage or abortion, and a history of childhood sexual abuse.¹

However, the biggest risk factor for postpartum depression is a previous history of depression. The risk of developing postpartum depression is 20 times higher in women who have suffered from depression previously compared to women who have not.⁴

Treatment of postpartum depression

The recommended treatment options for postpartum depression are antidepressant medication and cognitive behavioural psychotherapy (CBT). However, women who are breastfeeding are likely to be concerned about the effects of medication on their babies. Although CBT can be effective for treating postpartum depression, only 10% of mothers suffering from postpartum depression seek treatment due to various barriers associated with taking therapy during this period. These barriers include time constraints, transportation, cost, access to childcare, and social stigma.^5,6

Prevention of postpartum depression and alternative treatment options are therefore necessary.

Exercise to prevent postpartum depression

One promising method to prevent and treat postpartum depression is exercise. Exercise or physical activity is defined as any bodily movement produced by the skeletal muscles that require an expenditure of energy.⁷ Many studies have already established that exercise is beneficial in preventing and treating depression among the general population.8,9 Exercise has been shown to improve the mood of people with mild to moderate depression as effectively as antidepressant medication, therapy, or social support.¹⁰

Exercise can play an essential role in the prevention of postpartum depression if started early on during pregnancy.

Current evidence that exercise provides protection from postpartum depression

Recent studies have provided evidence, demonstrating that exercise carried out after birth reduces the risk of postpartum depression. Light-to-moderate-intensity aerobic exercise has been shown to improve symptoms and increase the likelihood of resolving mild-to-moderate depressive symptoms.^11,12

In 2017, a meta-analysis of several recent studies concluded that there was a decrease in postpartum depressive symptoms for those mothers who participated in exercise interventions during pregnancy and the postpartum period.¹³ Another study in 2019 reviewed all previous research on the topic of postpartum depression and exercise, including the results from 16 studies² It was shown that regular exercise during pregnancy and in the postpartum period, compared to being inactive significantly reduced the risk of developing depression in mothers during both pregnancy and after giving birth. Exercise has also been shown to improve the quality of life and reduce fatigue levels in young mothers.

Although the association between exercise and the prevention of postpartum depression has been established, some areas still require further research. Little is currently known about which dose of exercise(frequency, duration and intensity) is most effective at preventing depression in mothers.. It is also not known whether there are differences between exercises carried out for different reasons such as leisure, transport, domestic, or occupational activities. And finally, more research is required to determine which pregnancy trimester exercise is most effective.

Overall, it can be concluded that exercise during pregnancy and the postpartum period is a safe method to achieve improved mental health and protect from postpartum depression. Exercise should be recommended to new and expecting mothers as an accessible means of both preventing and treating mental health conditions.

How does exercise help with depression?

The mechanisms underlying the antidepressant effects of exercise are not yet completely understood. One hypothesis is that exercise helps with depression through biological mechanisms, for example, by increasing endorphin(hormone) levels. Endorphins are associated with improved mood, euphoria, and enthusiasm.¹⁴ Exercise also increases the level of neurotransmitters such as serotonin, dopamine, and noradrenaline in the brain., which are associated with feelings of satisfaction and euphoria. On the other hand, the depletion of neurotransmitters in the brain is one theory for the development of depression⁽¹⁵⁾.

Additionally, several psychological mechanisms have also been proposed. For example, enhancing self-esteem and self-efficacy. It has been reported that exercise results in enhanced feelings of self-efficacy, which, in turn, are inversely related to feelings of depression.¹⁶ Another way in which exercise can exert antidepressant effects may be through distraction; exercise provides a distraction from worries or depressing thoughts.

Finally, when exercise is carried out with other people, it can also lead to reduced depressive symptoms through social mechanisms, such as increased social support^.17

Recommended exercise for new mothers

For healthy pregnancies without medical complications or contraindications, exercise is considered safe and encouraged. Exercise in pregnancy is associated with minimal risks and benefits for most women, although slight modifications to exercise routines may be necessary.

The current guidelines for pregnant women or new mothers from the Centre for Disease Control and Prevention (CDC) suggest a minimum of 150 minutes of moderate-intensity aerobic physical activity per week. This could be, for example, 30 minutes a day, 5 days a week. Recommended exercise includes brisk walking, swimming, cycling, or stretching.¹⁸ High-intensity aerobic exercise such as running, may be beneficial during and after pregnancy for those mothers who did so beforehand but should always consult with the doctor if it is advisable.

Exercise has been shown to improve the health of the mother and also their unborn child by improving the sleep cycle, managing gestational weight, and reducing the risk of gestational diabetes.¹⁹

Summary

Exercise is important to protect against postpartum depression. New mothers are recommended to carry out at least 150 minutes of moderate-intensity physical activity per week. Exercise should be carried out not only after birth but also during pregnancy. More strenuous exercise can also be carried out if you are already doing it, but it is not advisable to start doing strenuous exercise for the first time during pregnancy or after birth.

Although there are currently only a small number of trials, the results demonstrate that exercise during pregnancy may protect against postpartum depression and could be recommended as an accessible means of preventing mental health disorders in new mothers.

Mental and physical health are strongly interconnected indicating that mental health can be enhanced through improvements in physical health. The healthy development of an infant depends on the mother’s health and well-being. Therefore, new mothers should always be advised about the recommended level of exercise and its benefits.