Factor Structure and Measurement Invariance of the Japanese Version of the Mother-to-Infant Bonding Scale

Background: Bonding disorders affect the growth and development of infants. In Japan, the Japanese version of the Mother-to-Infant Bonding Scale (MIBS-J) is widely used for early detection of bonding disorders. Repeated use of a questionnaire has problems of reduced validity. In order to correctly detect bonding disorders at multiple time points, it is necessary to confirm the measurement invariance of the scale. Baba et al. reported that invariance of the MIBS-J factor structure could only be obtained by abridging the scale into three items. Purpose: The aim of this study was to 1) confirm the factor structure and measurement invariance of the MIBS-J between two measurement times and 2) to examine factors that can be used without being affected by measurement time in order to identify item that contribute to measure met invariance. Methods: We analysed the data of 1049 and 878 mothers with a neonate collected in two waves: 5 days (Wave 1) and 1 month postpartum (Wave 2). Exploratory and confirmatory factor analyses were conducted on the data randomly divided into two groups in each wave. Results: The three-item model (MIBS-J items 1, 6, and 8) was most accepted. Measurement invariance and structural invariance were confirmed in the model. This was consistent with Baba et al.’s model. Conclusion: The three MIBS-J items showed measurement invariance and structural invariance in Japanese mothers during 1 month postpartum.

The Inter Relationship of Mental State between Antepartum and Postpartum Assessed by Depression and Bonding Scales in Mothers

The number of deaths caused by child abuse is increasing, which is one of social concerns. The mental health of mothers might be related to child abuse. The aim of this study was to examine and compare the mental state of mothers in both the antepartum and postpartum period assessed by the Edinburgh Postnatal Depression Scale (EPDS) and Mother-Infant-Bonding-Scale (MIBS), and compare the results. Participants (n = 134) were recruited twice in antepartum medical checkups (20 to 36 weeks of gestation) and postpartum medical checkups (1 month after birth). Information on characteristics of participants was collected from medical records in both periods. Family function and ante-postpartum mental health were assessed by Family APGAR, EPDS, and MIBS. Antepartum depressive state was related to postpartum depressive state (p = 0.015), antepartum bonding was related to bonding in postpartum bonding (p = 0.0001), and antepartum bonding disorder was related to postpartum depressive state (relative risk = 11.7). Worries about costs and poor of family function were related to the mental health of mothers in both the antepartum and postpartum periods. Antepartum depressive state is an indicator of postpartum depression. We suggested that health professionals conduct an evaluation of mother’s mental health and related factors in the antepartum period. The present findings emphasize the importance of antepartum mental health as a predictor of postpartum depression and bonding disorder.