Perinatal depression is still a significant public health problem affecting maternal well-being and infant health around the world. Although researchers have identified a wide range of risk factors over the past two decades, no single leading predictor of maternal depression has yet been established. The research question is whether the same risk factors explain both prenatal and postpartum depression, and to what extent factors related to childbirth impact postpartum depression. In this longitudinal study, women completed a questionnaire in their third trimester of pregnancy (on average at 31 weeks of gestation - Time 1), and again approximately six weeks after birth (Time 2). Of the 150 women who completed the paper questionnaire in the first phase (Time 1), 120 took part in the second phase of the postpartum assessment (Time 2). A binary logistic regression analysis was performed to identify factors associated with depression at Time 1 and Time 2. Trait anxiety (STAI-T) and negative attitudes towards pregnancy and motherhood (PRE-MAMA) were found to be the only factors that predicted elevated antenatal depression. Together, these factors explained 60% of the variance. The symptoms of depression experienced during pregnancy were the most significant predictor of postpartum depression. The second most significant predictor of postpartum depression was caesarean section. These findings corroborate the hypothesis that the postpartum period should not be regarded as the sole critical phase for screening and psychological intervention. The mood of the pregnant woman, particularly during the third trimester, and the type of delivery should also be considered.