This research examined whether a higher prevalence of postnatal depression or different postnatal psychological outcomes occur for mothers depending on the gestational age of the infant at birth. Mothers were compared following preterm (28 to 36-weeks gestation) and full-term (37 to 42-weeeks gestation) delivery to ascertain whether having a preterm infant increased the diagnosis of postnatal depression or psychosocial problems (e.g., negative birth experience, feeling more anxious, limited coping strategies) following childbirth.

Most research conducted thus far in the field has related primarily to mothers of full-term infants, although mothers of preterm infants tend to encounter more problems due to the unexpected nature of the birth and ongoing difficulties with the infants' health. Such events might be experienced as stressful and could place mothers of preterm infants at higher risk of developing postnatal depression. The research sample included 102 women who delivered preterm or full-term infants at King Edward Memorial Hospital. The diagnosis of depression was achieved by clinician-rated interviews at one and twelve-months postpartum, while details of postnatal reactions and difficulties were elicited by a range of self-report measures completed at one, three and nine-months postpartum.

The results confirmed the research hypotheses. Mothers of preterm infants were three times more likely to be diagnosed with major or minor depression following childbirth than mothers of full-term infants. Mothers of preterm infants were also more likely to experience the impact of the birth negatively, encounter infant complications, have higher situation-specific anxiety, and feel less competent as a parent or satisfied with parenting, when history of depression was controlled. These results need to be acknowledged in planning preventive services for high-risk populations.