2.1. Study Design
The INTER-ACT RCT was a multicenter RCT with a longitudinal study design. Participants received the first study visit 6 weeks after childbirth. The intervention group received the next study visit on week 12 and months 6, 12, 18, 24 and 30 after childbirth and the control group at months 6, 12, 18, 24 and 30. Once participants were pregnant, the visits on previous dates were discontinued and replaced with a pregnancy visit in the first, second and third trimesters. The intervention group received 4 e-health-supported face-to-face coaching sessions during the first 6 months after childbirth in addition to usual care (weeks 6, 8 and 12 and month 6). The control group received usual care only.To address the current research question, we focused on the group of women who started a subsequent pregnancy and who completed mental health questionnaires at 6 weeks after childbirth and at the start of the next pregnancy.The study was conducted according to the guidelines of the Declaration of Helsinki and was approved on 9 March 2017 by the Clinical Trial Centre/Ethical Committee UZ Leuven (protocol code B322201730956/S59889). All participants confirmed their participation by written informed consent.