Abstract: Objective To explore the mediating effect of paternal depression and family function between maternal depression and mother-infant bonding after the discharge of preterm infants. Methods With convenience sampling, the parents of premature infants discharged from the neonatal center of a tertiary children's hospital were investigated from July 2020 to January 2021. Mothers completed the Self-rating Depression Scale, Family Assessment Device and Chinese version of Maternal Attachment Inventory and fathers completed the Self-rating Depression Scale. Results The total score of paternal depression, maternal depression, family function and mother-infant bonding were 49.34±11.69, 53.02±11.62, 2.28±0.31, 78.54±14.73, respectively. Paternal depression, maternal depression and family function were negatively correlated with the mother-infant bonding(r=-0.272,-0.331,-0.174,all P<0.01). Maternal depression had a directly negative predictive effect on mother-infant emotional connection (β=-0.299,P<0.001); paternal depression and family function played a partial mediating role between maternal depression and mother-infant bonding, with mediating effect value of -0.082, and the proportion of the mediating effect was 36.52%. Conclusion Depression of parents of preterm infants is significantly higher than domestic norm and family function is at a medium low level. Parents' depression and family function can directly or indirectly affect the establishment of the mother-infant bonding. Medical staff should pay attention to the life care and disease rehabilitation after the discharge of preterm infants as well as parents' emotion counseling, family function and the establishment of mother-infant bonding in order to promote the development of premature infants' physiological and psychological behavior.

Key words: preterm infant, post-discharge, parental depression, family function, mother-infant bonding, mediating effect