Factor Structure of the Postpartum Bonding Questionnaire in a US-Based Cohort of Mothers

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. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by grant R01MH126531 from National Institute of Mental Health (Dumitriu), contract 75D30120C08150 with Abt Associates from US Centers for Disease Control and Prevention (Dumitriu), grant P-6006251-2021 from W.K. Kellogg Foundation (Dumitriu), gift funds from Einhorn Collaborative (Dumitriu), grant 201910MFE-430349-268206 from the Canadian Institutes of Health Research (Lavallee) and grant from Fonds de Recherche du Quebec en Sante (Lavallee). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Study procedures were approved by the CUIMC Institutional Review Board and written informed consent was obtained from all participants. I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes The dataset analyzed here are available from the corresponding authors (AL or DD) upon reasonable request.