Revision and validation of a scale to assess pregnancy stress.

Background: Pregnancy is a potentially stressful event. Prenatal stress alters maternal endocrine and immune systems, has been implicated in the etiology of prenatal complications or postnatal psychiatric disorders, and may adversely affect fetal health. The 30-item Pregnancy Stress Rating Scale (PSRS), initially developed in 1983 by Chen and colleagues, is the only measure to date designed specifically to evaluate prenatal stress.

Purpose: The purpose of this study was to reconsider and revise the 30-item PSRS and validate the new PSRS.

Methods: A cross-sectional design was used. Adding new items of pregnancy stress generated from clinical experience and expert recommendations resulted in a 40-item revised PSRS that was more reflective of current social conditions. Three hundred pregnant women, recruited from the antenatal clinic of a medical center in southern Taiwan, completed the revised PSRS to assess its internal consistency, test-retest reliability, construct validity, and convergent and discriminate validity.

Results: The final 36-item PSRS (PSRS36) was derived by deleting four items with relatively low item-total correlation coefficients or factor loadings. The resultant 36-item scale showed good internal consistency (α = .92) and 2-week test-retest reliability (r = .82). Factor analysis confirmed construct validity and suggested five prenatal stress dimensions, which explained 52.17% of the total variance. Convergent and discriminate validities were indicated by significant correlations among the PSRS36, Perceived Stress Scale, and Interpersonal Support Evaluation List.

Conclusions: The PSRS36 is a psychometrically sound and practical tool for nurses and other healthcare providers to assess prenatal stress and to examine intervention protocols in Taiwanese prenatal women. More research is recommended to determine whether the PSRS36 may be used in other racial-ethnic groups.