Background Mother-infant bonding provides the foundation for secure attachment through the lifespan and organizes many facets of infant social-emotional development, including later parenting. Aims To describe maternal bonding to offspring across the pregnancy and postnatal periods, and to examine a broad range of sociodemographic and psychosocial predictors of the maternal-offspring bond. Methods Data were drawn from a sample of 372 pregnant women participating in an Australian population-based longitudinal study of postnatal health and development. Participants completed maternal bonding questionnaires at each trimester and 8 weeks postnatal. Data were collected on a range of sociodemographic and psychosocial factors. Results Bonding increased significantly through pregnancy, in quality and intensity. Regression analyses indicated that stronger antenatal bonding at all time points (trimesters 1 through 3) predicted stronger postnatal bonding. Older maternal age, birth mother being born in a non-English speaking country, mother not working full time, being a first-time mother, breast-feeding problems, and baby's crying behavior all predicted poorer bonding at 8 weeks postpartum. Conclusion These novel findings have important implications for pregnant women and their infant offspring, and for health care professionals working in perinatal services. Importantly, interventions to strengthen maternal-fetal bonding would be beneficial during pregnancy to enhance postnatal bonding and infant health outcomes.