Health Mode On and Health Mode On Plus: a multisite protocol to assess and promote mental wellbeing and healthy lifestyles among Italian university students.

Postpartum depression is a psychiatric condition that can significantly impact the mental health of the mother and her relationship with the infant(s). This condition affects between 6.5% and 20% of postpartum women worldwide. Diagnostic suspicion typically arises when the mother presents symptoms such as anxiety, irritability, sleep disturbances, a persistent feeling of being overwhelmed, sadness, frequent crying, insecurity regarding newborn care, concerns about harming the baby, and suicidal ideation. The main risk factor is a personal history of depression or anxiety that was not identified during pregnancy. Although the pathophysiology of postpartum depression remains unclear, contributing factors may include the abrupt decline in reproductive hormone levels following childbirth, genetic predispositions, and social factors. Among the social determinants, lack of family support, marital conflicts, history of sexual abuse, and past traumatic experiences are particularly noteworthy. Twin pregnancies account for 2% to 3% of all births. However, multiple gestations are associated with a significantly higher incidence of obstetric complications, such as preterm birth, fetal growth restriction, cesarean delivery, postpartum hemorrhage, and neonatal intensive care unit (NICU) admission. These factors, combined with increased emotional burden, may significantly contribute to the psychological vulnerability of postpartum women. Accordingly, some studies have shown that twin pregnancies are associated with a higher risk of postpartum depression compared to singleton pregnancies, with this risk reaching up to 40% in recent cohorts. Despite the growing international literature, there is a notable scarcity of studies in Brazil that investigate the association between twin pregnancies and postpartum depression. Most available evidence comes from international cohorts, and few national studies address the psychosocial and emotional specificities of this group of women, particularly in public health contexts. This knowledge gap emphasizes the originality and relevance of the present study, which seeks to contribute to a more contextualized understanding of this mental health problem and to reinforce the need for preventive psychological strategies in prenatal and postpartum care.