Background: The Mother-Infant Bonding Questionnaire (MIBQ) has been widely used to assess maternal emotional involvement with infants. Although the reliability and validity of the MIBQ in the postpartum period has been confirmed, it remains unclear whether the MIBQ is appropriate to assess maternal bonding in both pregnancy and the postpartum period over time. Our study were aimed to 1) examine the reliability and validity of the MIBQ for clinical use among pregnant and postpartum women; and 2) examine the factor structure of the items, create subscales, and confirm the stability of the MIBQ in the pregnancy and postpartum periods.
Methods: Participants (n = 751, mean age 32.1 ± 4.4 years) completed the MIBQ and the Edinburgh Postnatal Depression Scale (EPDS) in early pregnancy (before week 25), in late pregnancy (around week 36), 5 days after delivery, and 1 month after delivery. We randomly divided participants into two sample sets. We conducted an exploratory factor analysis of the nine MIBQ items using data from one group of mothers (Group 1; n = 376) in all four periods. The factor structure derived from the exploratory factor analysis was confirmed by a confirmatory factor analysis in the second group (Group 2; n = 375) of mothers in all four periods.
Results: Exploratory factor analysis yielded two factors: Lack of Affection (LA) and Anger and Rejection (AR). Confirmatory factor analysis demonstrated that LA and AR factors existed for the MIBQ in all periods. Cronbach's alpha coefficients were 0.879 and 0.584, respectively. The scores for LA and AR were significantly correlated over the four time periods. Mothers with higher AR scores on the MIBQ at any of the four periods had higher scores on the EPDS.
Conclusions: The MIBQ has two subscales regardless of the timing of the assessment. The MIBQ is appropriate for pregnant as well as postpartum women to assess maternal bonding toward the fetus and infant.