Effect of emotion regulation training based on the Gross Model on rumination in mothers of premature infants hospitalized in neonatal intensive care units: A randomized controlled trial

Preterm birth and subsequent hospitalization of newborns in neonatal intensive care units (NICUs) represent a highly stressful experience for mothers, often leading to heightened emotional distress and repetitive negative thinking patterns. Persistent rumination can interfere with maternal sensitivity, bonding, and the quality of infant care. This randomized controlled trial aimed to examine the effect of emotion regulation training based on Gross’s model on rumination among mothers of preterm infants hospitalized in NICUs in Gorgan, Iran. A total of 60 mothers were selected through simple random sampling and assigned to experimental and control groups. The intervention group participated in eight 60–90-minute group sessions focusing on theoretical and practical skills in emotion regulation, including cognitive reappraisal, attention modification, and adaptive expression of emotions. Data were collected using the Nolen-Hoeksema and Morrow Ruminative Responses Scale (1991). The results indicated no significant difference between groups before the intervention (P=0.690). However, after controlling for pretest scores, analysis of covariance (ANCOVA) revealed a significant reduction in rumination scores in the intervention group compared to the control group (P<0.010, η²=0.09). These findings suggest that Gross’s emotion regulation training effectively reduces rumination in mothers of preterm infants by enhancing cognitive reappraisal and emotional management skills. The intervention enabled mothers to cope more adaptively with the stress of NICU hospitalization, promoting psychological adjustment and maternal well-being. Incorporating structured emotion regulation programs into nursing care for mothers of preterm infants may improve emotional health, strengthen mother–infant bonding, and enhance the overall quality of neonatal care. Further research with larger and more diverse samples is recommended to confirm and extend these findings.