The study aimed to investigate the persistence or changes in trait resilience of parents over a 6-year period and its association with stressful life events (SLEs). Furthermore, we explored the potential protective effect of trait resilience against exposure to stressful life events and their negative mental health consequences. The study population was drawn from the ongoing FinnBrain Birth Cohort Study and included 1388 mothers and 657 fathers who completed the CD-RISC-10 questionnaire during pregnancy and again 6 years later. Data collection involved self-report questionnaires, including CD-RISC-10, EPDS, SCL-90, and a questionnaire on SLEs. Data analysis utilised linear regression and statistical assessments. Parents in the highest or lowest quartile of resilience showed greater stability in resilience scores over time compared to those in the middle quartiles. Trait resilience during pregnancy was significantly associated with resilience 6 years later. SLEs did not moderate this association. Additionally, higher trait resilience consistently associated with lower levels of distress symptoms. The investigation of SLEs may require more nuance due to their event-specific variability of impact. Furthermore, the study's sample size of individuals who experienced a high frequency of stressful life events was limited. Trait resilience appears to be rather stable, but also susceptible to some change. Because of its persistency and the positive impact on mental health it is worthwhile to be assessed as a part of comprehensive evaluation of parents' mental health.