Maternal postnatal depression is estimated to affect 6 – 38% of women in high income countries. Not only is it by nature distressing, it is also associated with health risks to the child. We need to know more about what causes postnatal depression in order to inform policy to prevent it.

One set of factors which could be important are aspects of the city environment such as noise, air polution and access to natural spaces. The period following birth is a particular vulnerable time and these factors could have a negative impact on maternal mental health. For example, air polution could affect the brain which could lead to an increased risk of depression. Road traffic noise could disrupt sleep leading to increased stress, and a lack of access to natural spaces could reduce opportunities to socialise and relax.

Whilst there is some evidence that these aspects of the city environment are related to depression in adults, very few studies have explored their relevance for postnatal depression. In this study we aim to use a large data resource including many European cities to investigate whether exposure to these different aspects of the city environment increases the risk of postnatal depression.