Reliability and Validity of a Modified Version of the Postpartum Bonding Questionnaire

Background. Maternal-infant bonding refers to the maternal emotional response to the infant. Although validated instruments for measurement of maternal-infant bonding exist, they are designed to identify women at risk for bonding impairment, rather than to quantitatively examine the state of the mother-infant relationship, as is desired for use in large research studies. This study reports the validity and reliability of a modified and shortened version of the Postpartum Bonding Questionnaire (PBQ) which was developed to measure variations in maternal-infant bonding in a large multisite research study.

Methods. The 13-item modified PBQ was administered via telephone interview to 3005 mothers 1 month after delivery of their first live-born infant. Factor analysis was completed to evaluate scale components. Internal reliability and validity were examined.

Results. The modified PBQ demonstrated acceptable internal reliability (Cronbach's alpha=0.773). Factor analysis revealed three main factors: emotional bond; confidence; and rejection. Consistent with extant literature, maternal-infant bonding was significantly negatively correlated with maternal stress (r=-0.31; p<0.01), pain (r=-0.137; p<0.01), infant colic (p<0.001) and postpartum depression (p<0.001), and positively correlated with maternal health (r=0.362; p<0.01), and social support (r=0.347; p<0.01), confirming construct validity.

Conclusions. The modified version of the PBQ provides a shortened instrument for measuring maternal-infant bonding with good reliability and validity in large population studies. The use of this instrument in maternal-child health research will help to advance understanding of maternal-infant bonding, a crucial component of the mother-child relationship.