Anxiety affects around one in five women during pregnancy and after birth. However, there is no systematic information on the proportion of women with perinatal anxiety disorders who want or receive treatment.

To examine (a) the prevalence of anxiety disorders during pregnancy and after birth in a population-based sample, and (b) the proportion of women with anxiety disorders who want treatment and receive treatment.

This study conducted 403 diagnostic interviews in early pregnancy (n = 102), mid-pregnancy (n = 99), late pregnancy (n = 102) or postpartum (n = 100). Participants also completed self-report measures of previous/current mental health problems and desire for treatment at every time point.

The prevalence of anxiety disorders over all time points combined was 19.9% (95% CI 16.1–24.1), with greatest prevalence in early pregnancy (25.5%, 95% CI 17.4–35.1). The most prevalent disorders were obsessive–compulsive disorder (8.2%, 95% CI 5.7–11.3) and generalised anxiety disorder (5.7%, 95% CI 3.7–8.4). The majority of women with anxiety disorders did not want professional help or treatment (79.8%). Most women with anxiety disorders who did want treatment (20.2%) were receiving treatment. The majority of participants with anxiety disorders had a history of mental health problems (64.6%).

Prevalence rates overall are consistent with previous research, lending validity to the findings. However, findings challenge the assumption that everyone with a psychological disorder wants treatment. These findings highlight the importance of relationship-based care, where individual needs and contextual barriers to treatment can be explored.