- To examine whether a pre-gestational diagnosis of depression is a risk factor for adverse obstetric and neonatal outcome. A retrospective cohort study investigating maternal characteristics, obstetrical and perinatal outcomes in singleton pregnancies of women with and without a diagnosis of depression was conducted. A pre-gestational diagnosis of depression was made by a psychiatrist or family physician and was recorded in the patients' chart. Multiple logistic regression models were used to control for possible confounders. During the study period, 256312 deliveries occurred. Out of which, 221 women (0.1%) had a pre-gestational diagnosis of depression. When examining obstetric outcomes, women with a diagnosis of depression were older (32.05±5.772 VS 28.56±5.851) and smokers (7.2% VS 1.1%), had a higher rate of preterm deliveries (37.99±2.989 VS 39.02±2.249) and cesarean sections (28.5% VS 13.6%) in comparison to the control group. When examining neonatal outcomes, neonates of women diagnosed with depression had a lower birth mean weight (3.038.47±649.6 VS 3183.44±551.8) and increased rates of perinatal mortality (3.2% VS 1.3%). Using a multiple logistic regression model, with perinatal mortality as the outcome variable to control for cofounders such as maternal age, preterm birth, chronic hypertension and gestational diabetes mellitus, a diagnosis of depression was not found to be an independent risk factor for perinatal mortality. Another multiple logistic regression model found advanced maternal age, smoking, preterm birth and labor induction to be associated with a diagnosis of depression. Pregnant women diagnosed with depression are at an increased risk for preterm birth, low birth weight, and cesarean sections. However, it was not associated with increased rates of perinatal mortality.