Introduction Despite the widespread, long-standing notion that pregnancy is a time of happiness and emotional well-being, accumulating evidence suggest that it does not protect women from mental illness. As their non-pregnant counterparts, pregnant women can experience new onset and recurrent mood, anxiety and psychotic disorders. Up to 40% of women with elevated postnatal EPDS (Edimburgh Postnatal Depression Scale) scores had high prenatal EPDS scores, thus suggesting that, for these women, there is a continuation of pre-existing symptoms into the postnatal period. These findings highlight the importance of encompassing the entire perinatal period when examining mental health disorders. The discipline of perinatal mental health encompasses the mental health of childbearing women from conception up to the end of the first postnatal year and also considers how perinatal mental health problems can contribute to adverse outcomes for infants as well as partners and other family members. Methods This report summarizes the knowledge regarding psychiatric disorders in pregnancy, considering the most relevant publications on perinatal mental health in the last fifteen years. An electronic search was conducted in MEDLINE and Medscape using the terms "pregnancy", "maternal mental illness", "perinatal depression and anxiety", "schizophrenia and pregnancy", "eating disorders", and childbearing". Results The literature taken into account suggests that women during pregnancy suffer from the spectrum of psychotic and non-psychotic disorders. The non psychotic disorders include major and minor depression, panic disorder, agoraphobia, generalized anxiety disorder (GAD) and obsessive compulsive disorder (OCD). Despite variability in assessment times and procedures, relatively consistent prevalence rates ranging from 1.3 to 2% have been reported for panic disorder during the perinatal period. Although symptoms of panic during this period are typical of symptoms in the general population, they are often interpreted in the context of pregnancy state, for example, women may interpret panic attacks as an indication that something is wrong with the foetus. The prevalence of Obsessive Compulsive Disorder during pregnancy is 0.2-1.2% and the rates reported in post-partum women (2.7-3.9%) are higher than in the general population. It has been extensively reported that obsessions in perinatal women often include fears of intentionally or accidentally harming the fetus or child. Obsessional thoughts about harming the infant are not specific to OCD and, at subclinical levels, they may be a normal feature of new parenthood. Depression is one of the most frequently encountered medical complications in pregnancy and the risk for depression increases even more during the postpartum period. Prevalence rates of depression are 7%, 12.8% and 12% for the first, second and third trimesters, respectively. While more women fulfil criteria for minor than major de-pression at this time, minor depression is associated with significant disability because it can be associated with other disorders. Like major depressive disorder, bipolar disorder (BD) affects pregnant women and poses substantial risk to the mother and foetus. Both schizophrenic and affective disorder patients have increased risk for symptom exacerbation during the immediate postpartum period. Individuals with any form of previous or current eating disorder who become pregnant represent a complex challenge for the clinician. The personality of the individual with an eating disorder may hamper mater-nal role acquisition during pregnancy, and pregnancy itself may trigger different concerns and fears that may favour the onset of postpartum depression. Conclusions If we expand our focus to look beyond postnatal psychiatric disorders, we can begin to examine the spectrum of both depressive and anxiety disorders across the "perinatal" period. Informed choices coupled with close psychiatric follow-up and coordinated care with the obstetrician are the elements of an optimal model for the management of psychiatric disorders during pregnancy.
