As research efforts in the field of pediatrics are oriented toward a better understanding of the synergistic relationship between different facets of early relational health (ERH) and child development and wellbeing, it is essential to focus on the quality of research instruments available for measuring different components of ERH. This study investigates the measurement characteristics of a widely used parent/caregiver-reported measure of bonding, the Postpartum Bonding Questionnaire (PBQ), in a US-based sample (n=610) of English-speaking biological mothers who completed the PBQ at 4 months postpartum. To evaluate the factor structure of the PBQ, confirmatory and exploratory statistical techniques were employed. The current study failed to replicate the PBQ's original 4-factor structure. Exploratory factor analysis results supported the creation of a 14-item abbreviated measure, the PBQ-14. The PBQ-14 showed evidence of good psychometric properties, including high internal consistency (ω=.87) and correlation with depression (r=.44, p<.001) assessed using the Patient Health Questionnaire (PHQ-9), as would be expected. The new unidimensional PBQ-14 is suitable for use in the US as a measure of general postnatal parent/caregiver-to-infant bonding.