Childbirth as a trauma: Psychometric properties of the impact event scale in Japanese mothers of neonates

摘要

Introduction: The purpose of this study was to evaluate the psychometric properties of the Impact of Event Scale (IES) among Japanese women after childbirth. Methods: Self-reported questionnaires were distributed to pregnant women in Kumamoto prefecture consecutively on three occasions: late pregnancy (N = 642) and five days (N = 416) and one month (N = 226) after delivery. Results. An exploratory factor analysis of the IES items at day 5 after childbirth yielded a two-factor structure (Intrusion and Avoidance) that was cross-validated by a confirmatory factor analysis. The IES subscale scores were correlated with other psychological measures rated at the same time, including postpartum depressive symptoms assessed with the Edinburgh Postnatal Depression Scale (EPDS) and perceived difficulty of childbirth experience. The Cronbach's alpha coefficients were .83 for Intrusion and .86 for Avoidance. Test-retest reliability between day 5 and one month after childbirth was .74 for Intrusion and .71 for Avoidance. Discussion: The results provide support for the IES as a valid and reliable measure of postnatal traumatic symptoms among Japanese women.