Research suggests that some fathers and birth partners can experience post-traumatic stress disorder after witnessing a traumatic birth. Birth-related PTSD may impact on many aspects of fathers’ and birth partners’ life, including relationship breakdown, self-blame and reducing plans for future children. Despite the potential impact on birth partners’ lives there is currently no measure of birth-related PTSD validated for use with birth partners. The current study therefore adapted the City Birth Trauma Scale for use with birth partners. The City Birth (...) Trauma Scale is a 29-item questionnaire developed to measure birth-related PTSD according to DSM-5 criteria: stressor criteria, symptoms of re-experiencing, avoidance, negative cognitions and mood, and hyperarousal, as well as duration of symptoms, significant distress or impairment, and exclusion criteria or other causes. A sample of 301 fathers/birth partners was recruited online and completed measures of birth-related PTSD, bonding, and demographic details. Results showed the City Birth Trauma Scale had good reliability and psychometric and construct validity. The fathers/birth partners version has the same two-factor structure as the original scale: general symptoms and birth-related symptoms, which accounted for 51% of the variance. PTSD symptoms were associated with preterm birth and maternal and infant complications. Overall, the City Birth Trauma Scale provides a promising measure of PTSD following childbirth that can be used in research and clinical practice. (shrink)