Women's mental health care related to the perinatal period, such as postpartum depression care, has become an area of focus for obstetricians and gynecologists. Obstetric clinical practice guidelines have also started referring to puerperal mental disorders and screening for mental disorders during pregnancy. Therefore, in 2020, we conducted a questionnaire survey through the Kinki Society of Obstetrics and Gynecology Perinatal Study Group to explore the current status of obstetricians' management of mental disorders during the perinatal period. This survey revealed that the execution rate of maternal mental health screening was 100%; however, about 40% of maternity facilities answered that psychiatric referrals made them feel stressed for reasons such as "it is difficult to recommend psychiatric consultations.
 At our hospital, a liaison psychiatric team (consisting of a specialist nurse for maternity care, pharmacist, social worker, and patient support center admission/discharge coordinating nurse) led by a liaison psychiatric nurse works as a multidisciplinary collaboration group. The team was formed in 2015; herein, we retrospectively studied the effect of the intervention by the liaison team. More specifically, the investigation was retrospectively performed from January 2011 to December 2019 using medical records from a single university medical hospital in Japan. The participants comprised pregnant women with mental disorders. Of the 4,066 women who delivered during the study period, 152 were detected as having access to the liaison team (2015～2019), while 92 were recognized as controls (2011～2014). Then, we conducted a comparative analysis between those who contact to the liaison team and the control group. We found that the liaison system was associated with an increased rate of referral to the local public health center (P=0.003). The system also significantly delayed the time at which patients first visited a psychiatrist because a psychiatric nurse could determine the urgency through interviews with the patients. The liaison nurse conducted interviews at obstetrics units, making it easier for obstetricians and gynecologists to refer pregnant women with psychiatric disorders and puerperal women to psychiatrist. In addition, the liaison system may contribute to reducing the burden on psychiatrists because the information for medical treatment is already recorded by the liaison team before the first visit to a psychiatrist. However, we believe that it is necessary to create awareness about the activities of multidisciplinary collaboration groups. This is because, when we approached a local obstetrician, they complained, "Why don't you approach a psychiatrist? If it's just an interview with a nurse, we can manage it."
 Author's abstract