Depression and marital distress are identified risks for parenting problems during the postnatal period, but less is known about how they impact parenting during the transition from the prenatal to postnatal period. Preterm birth of an infant has shown to be an independent risk factor for maternal postnatal depression. The aims of this thesis were 1) to explore the effects of prenatal and postnatal depressive symptoms and marital distress on both parents’ parental representations and on postnatal breastfeeding (Study I and II) and 2) to develop a comprehensive intervention to support parenting after preterm birth and evaluate the effect of the intervention on maternal postnatal depressive symptoms (Study III and IV). 

The results showed that prenatal maternal depressive symptoms were associated with suboptimal quality of mothers’ prenatal representation of their unborn infant and their relationship with the infant. The mothers’ prenatal depressive symptoms predicted postnatal depressive symptoms, which were associated with shorter duration of exclusive breastfeeding. Fathers’ marital distress increased their likelihood of having suboptimal prenatal representations. A new intervention, the “Close Collaboration with Parents,” was developed and successfully implemented. The intervention decreased the level of postnatal depressive symptoms among mothers of preterm infants. 

In conclusion, prenatal and postnatal depressive symptoms of mothers were found to be risk factors for the developing mother-infant relationship in the transition to parenthood, whereas only the marital distress had a negative impact on the fathers’ prenatal representations. In addition, postnatal depression symptoms among mothers of preterm infants were found to be decreased by the new comprehensive intervention.