LAUSR

Purpose Maternal depression has been associated with bonding difficulties and lower maternal sensitivity in observed mother–infant interactions. However, little research has examined the impact of disordered personality traits in mothers on these outcomes. We investigated the association between disordered personality traits in mothers measured during pregnancy and postnatal (a) self-reported bonding with infant; (b) observational mother–infant interactions. Methods Five hundred fifty-six women were recruited during early pregnancy and subsequently followed up at mid-pregnancy (approximately 28 weeks’ gestation) and when infants were aged approximately 3 months ( n  = 459). During early pregnancy, data were collected on disordered personality traits (using the Standardised Assessment of Personality Abbreviated Scale) and depressive symptoms (using the Edinburgh Postnatal Depression Scale). At 3 months postpartum, self-reported perceived bonding (using the Postpartum Bonding Questionnaire) were collected. A sub-sample of women additionally provided observational mother–infant interaction data ( n  = 206) (coded using the Child–Adult Relationship Experimental Index). Results Higher disordered personality traits was not associated with maternal perceptions of bonding impairment, but was associated with reduced maternal sensitivity during observational mother–infant interactions [adjusted for age, education, having older children, substance misuse prior to pregnancy, infant sex and gestational age: coefficient = − 0.28, 95% CI = − 0.56 to − 0.00, p  < 0.05]. After adjusting for depressive symptoms, the association was attenuated [coefficient = − 0.19, 95% CI = − 0.48 to 0.11, p  = 0.217]. Conclusions Mothers with disordered personality traits did not perceive themselves as having bonding impairments with their infants but were less sensitive during observed interactions, though depressive symptoms attenuated this relationship. Both depression and disordered personality traits need to be addressed to optimize mother–infant interactions.