RELAX Perinatal Digital Intervention to Prevent Increasing Anxiety

Importance Anxiety disorders affect 1 in 5 pregnant women and birthing people. Cognitive bias modification for interpretation reduces anxiety and repetitive negative thinking (RNT; a risk factor for anxiety) among nonpregnant samples. Objective To evaluate whether adding pregnancy-tailored cognitive bias modification for interpretation to usual maternity care (UC) prevents increased anxiety during pregnancy; reduces anxiety, depression, and RNT before and after birth; and improves functioning before and after birth compared with UC. Design, Setting, and Participants The RELAX (Reducing Levels of Anxiety) 2-arm, parallel-group, multisite, superiority, phase 2b randomized clinical trial recruited participants from June 2023 to July 2024, with final assessment in April 2025. Participants included pregnant individuals in the UK at 16 to 28 weeks’ gestation, with high RNT and up to moderate anxiety, recruited via antenatal clinics or self-referral. Intervention Participants were randomized to the self-led digital intervention (RELAX plus UC), involving twelve 17-minute sessions over 4 weeks, or to UC. Main Outcomes and Measures Assessments took place at baseline before randomization (T0) and 4 weeks (T1), 8 weeks (T2), and 36 weeks (T3; 12-24 weeks after birth) after randomization. The primary outcome was anxiety, as assessed by the 7-item Generalized Anxiety Disorder scale (GAD-7) at T2 and as a secondary outcome at T3. Secondary outcomes included RNT (assessed by the 10-item trait version of the Repetitive Thinking Questionnaire [RTQ-10]), depression (general and perinatal, assessed by the Patient Health Questionnaire–9 [PHQ-9] and Edinburgh Postnatal Depression Scale [EPDS]), perinatal anxiety (assessed by the Perinatal Anxiety Screening Scale [PASS]), worry (assessed by the Penn State Worry Questionnaire [PSWQ]), and functioning (assessed by the Work and Social Adjustment Scale [WSAS]). Interpretation bias at T1 was the hypothesized mechanism. Analysis was performed using a modified intention-to-treat approach. Results A total of 268 participants were randomized (mean [SD] age 33.7 [3.9] years; 174 [64.9%] married). Anxiety was significantly lower for RELAX participants vs UC (mean GAD-7 difference, –1.5; 95% CI, −2.4 to −0.6; P = .001). Depression (mean PHQ-9 difference, –0.8; 95% CI –1.5 to –0.1; and mean EPDS difference, –1.1; 95% CI, –2.0 to –0.2), RNT (mean RTQ-10 difference, –2.7; 95% CI, –4.5 to –0.9), worry (mean PSWQ difference, –3.6; 95% CI, –5.9 to –1.3), and perinatal anxiety (mean PASS difference, –5.5; 95% CI, –8.2 to –2.8) were significantly lower at T2. Effects on general anxiety (mean GAD-7 difference, –1.0; 95% CI, –1.9 to –0.1), postnatal depression (mean EPDS difference, –1.3; 95% CI, –2.4 to –0.2), and RNT (mean RTQ-10 difference, –2.4; 95% CI, –4.6 to –0.2) were sustained at T3. RELAX promoted more positive interpretations vs UC (mean difference, 2.1; 95% CI, 1.8-2.3) that did not mediate effects at T2 (indirect effect on GAD-7, –0.2; percentile bootstrap 95% CI, –0.4 to 0.1). Functioning did not differ at T2 (mean WSAS difference, –1.0; 95% CI, –2.5 to 0.5) or T3 (mean WSAS difference, –0.8; 95% CI, –2.7 to 1.2), nor did perinatal anxiety (mean PASS difference, –2.1; 95% CI, –5.5 to 1.4), general depression (mean PHQ-9 difference, –0.2; 95% CI, –1.2 to 0.9), or worry (mean PSWQ difference, –1.4; 95% CI, –4.1 to 1.3) at T3. Conclusions and Relevance In this randomized clinical trial, anxiety was lower during pregnancy and postnatally for RELAX plus UC participants compared with those receiving UC. Integrating RELAX into maternity care for those at risk of increased anxiety has potential to improve maternal mental health. Trial Registration https://www.isrctn.com/ISRCTN12754931