A range of psychological disorders occur in women in the postpartum period. These include "the blues", which occurs in the first days after birth and which is very common and self-limiting; severe psychoses often associated with mania or bipolar illness, occurring in the first weeks after birth; and mild to moderate depression, occurring weeks to months after birth. Studies have been done focused on postpartum psychosis using a retrospective investigation, which gave only a limited material on the prevalence of psychological disorders in postpartum women. The investigators hypothesized that different pathways to psychosis function as the risk factors which may be overlapped, truly independent, mediating, or moderating, in new mothers who are at high risk and/or during the early period of delivery. In addition, the investigators purposed that the temporal sequence of biological, social and demographic variables are also the potential factors contributing to the development of postpartum psychosis.

Inclusion Criteria:

• Pregnant women
• Chinese

Exclusion Criteria:

• Age < 18 years or > 50 years
• Gestational age < 32 weeks

Parturients undergoing spontaneous or induced labor or cesarean delivery