Mental health disorders are common in pregnancy and after childbirth with over 10% of women manifesting some form of mental illness during this time. Maternity services will encounter women with symptoms that vary in severity from mild self-limiting to potentially life-threatening. These conditions carry risks for both the woman and the fetus/newborn. Detecting women with, or at risk of, a serious mental health disorder and enabling them to access appropriate care in a timely fashion is a shared responsibility. However, given the frequency of contact they have with women through this period, maternity services have a pivotal role. From a mental health perspective, high-risk pregnancies are those primarily associated with serious mental illness (psychotic illnesses, bipolar disorder and severe depressive episodes). Healthcare professionals caring for pregnant women should have the appropriate skills to detect serious mental illness and identify women at risk and how to access specialist mental health care.