Background: Pregnancy is a time of increased vulnerability for the development of anxiety and depression. This systematic review aims to identify the main risk factors involved in the onset of antenatal anxiety and depression.

Methods: A systematic literature analysis was conducted, using PubMed, PsychINFO, and the Cochrane Library. Original papers were included if they were written in English and published between 1st January 2003 and 31st August 2015, while literature reviews and meta-analyses were consulted regardless of publication date. A final number of 97 papers were selected.

Results: The most relevant factors associated with antenatal depression or anxiety were: lack of partner or of social support; history of abuse or of domestic violence; personal history of mental illness; unplanned or unwanted pregnancy; adverse events in life and high perceived stress; present/past pregnancy complications; and pregnancy loss.

Limitations: The review does not include a meta-analysis, which may have added additional information about the differential impact of each risk factor. Moreover, it does not specifically examine factors that may influence different types of anxiety disorders, or the recurrence or persistence of depression or anxiety from pregnancy to the postpartum period.

Conclusions: The results show the complex aetiology of antenatal depression and anxiety. The administration of a screening tool to identify women at risk of anxiety and depression during pregnancy should be universal practice in order to promote the long-term wellbeing of mothers and babies, and the knowledge of specific risk factors may help creating such screening tool targeting women at higher risk.