To compare the effect of a 3D-printed model versus 3D printed pictures on maternal– and paternal–fetal attachment, pregnancy-related anxiety, and depression in parents in the third trimester.

Randomized controlled trial.

University- and clinic-affiliated hospital system.

Between August 2020 and July 2021, we screened 419 women for eligibility. A total of 184 participants (n = 95 women and n = 89 men) were included in the intention-to-treat analysis, of whom 47 women and 44 men received the 3D-printed model, whereas 48 women and 45 men received the 3D printed picture.

Participants completed a set of questionnaires before they received third trimester 3D ultrasonography and a second set of questionnaires approximately 14 days after the study ultrasonography. The primary outcome was the global Maternal and Paternal Antenatal Attachment scale scores. Secondary outcomes included the Maternal and Paternal Antenatal Attachment subscale scores, global Generalized Anxiety Disorder–7 scores, global Patient Health Questionnaire–9 scores, and global Pregnancy-Related Anxiety Questionnaire–Revised (second version) scores. We used multilevel models to estimate the effect of the intervention.

We found a statistically significant increase in mean attachment scores after the 3D printed picture and 3D-printed model intervention of 0.26, 95% confidence interval (CI) [0.22, 0.31], p < .001. Additionally, we found statistically significant improvement in depression (mean change = –1.08, 95% CI [–1.54, –0.62], p < .001), anxiety (mean change = –1.38, 95% CI [–1.87, –0.89], p < .001), and pregnancy-related anxiety (mean change = –2.92, 95% CI [–4.11, –1.72], p < .001) scores. We found no statistically significant between-group differences related to maternal or paternal attachment, anxiety, depression, or pregnancy-related anxiety.

Our findings support the use of 3D printed pictures and 3D-printed models to improve prenatal attachment, anxiety, depression, and pregnancy-related anxiety.