IntroductionThe birth of a preterm infant evokes considerable psychological distress in mothers and is associated with an increased risk for postpartum depression.ObjectivesThe aim of this study was to assess the prevalence of postnatal depression among preterm infant mothers and to identify highlighting associated factors.MethodsWe conducted a cross-sectional, descriptive and analytical study, including 97 mothers of premature infants who presented to the outpatient unit of neonatology at the UH Hedi Chaker of Sfax in Tunisia. For each mother, we collected sociodemographic and obstetric data. We used the Edinburgh Postnatal Depression Scale (EPDS) for screening postpartum depression.ResultsAverage age of mothers was 30.2 years. Average gestational age was 32.82 weeks. Almost all the mothers were married (99%), had a satisfactory couple relationship (93.7%), almost two thirds were multiparous (64.9%), and 77.3% gave birth by caesarean section. Prematurity was unexpected by 56.7% of women. Regarding newborns, digestive problems were noted in 25.8% of cases and sleep disturbances in 20.6% of them. Prevalence of depression in the population studied was 39.2%. It was significantly associated with unexpected prematurity (P < 0.001), impaired couple relationship (P = 0.001), digestive problems (P = 0.013) and sleep disturbances (P = 0.002).ConclusionMothers of preterm infants seem to be particularly vulnerable to postpartum depression. Systematic screening for depressive symptoms in this obstetric population can help to have an optimal psychological outcomes for mothers and infants during a crucial period of development of mother–infant coregulation.Disclosure of interestThe authors have not supplied their declaration of competing interest.