362 British Journal of Health Psychology (2012), 17, 362–378 C  2011 The British Psychological Society The British Psychological Society www.wileyonlinelibrary.com The effect of an expressive writing intervention (EWI) on stress in infertile couples undergoing assisted reproductive technology (ART) treatment: A randomized controlled pilot study Signe Matthiesen 1 ∗ , Hillary Klonoff-Cohen 2 , Robert Zachariae 1,3 , Mikael B. Jensen-Johansen 1,3 , Berit K. Nielsen 1,3 , Yoon Frederiksen 1 , Lone Schmidt 4 and Hans Jakob Ingerslev 5 1 Department of Psychology, Aarhus University, Denmark 2 Department of Family and Preventive Medicine, University of California, San Diego, USA 3 Department of Oncology, Aarhus University Hospital, Denmark 4 Department of Public Health, Section of Social Medicine, University of Copenhagen, Denmark 5 The Fertility Clinic, Aarhus University Hospital, Denmark Objectives. Infertile couples undergoing fertility treatments may experience stress and could benefit from psychological intervention. Expressive Writing Intervention (EWI) has shown promising results on various psychological outcomes, yet only one study has applied the method to infertility-related stress. Our aim was to assess feasibility and effectiveness of EWI for patients in treatment with Assisted Reproductive Technology (ART). Design and participants. Patients enrolling in their first ART treatment at the fertility clinic, Aarhus University Hospital, Denmark were offered to participate. A total of 82 participants (45 women, 37 men), mean age: 33.17, were randomized to home- based EWI or neutral writing control group and completed an infertility-related stress questionnaire at treatment enrollment, 3 weeks later (at the time of down regulation), and 6 weeks after the intervention. The intervention took place 2 weeks after treatment start. Results. Mixed between-within ANOVA showed a main effect of time (Wilks Lambda = 0.68, F(2,28) = 6.48) as well as a significant interaction effect between group (control/ EWI) and time (Wilks Lambda = 0.83, F(2,28) = 2.92). Infertility-related stress decreases were observed after the intervention in the EWI group compared to controls. Six weeks after the intervention, stress tended to increase in both groups, with ∗ Correspondence should be addressed to Signe Matthiesen, Jens Chr. Skousvej 4, 8000 Aarhus C, Denmark (e-mail: signem@psy.au.dk). DOI:10.1111/j.2044-8287.2011.02042.x