Search strategy and study selection
We searched for randomised controlled trials, published in peer-reviewed journals, in the databases Pubmed, Embase and PsychINFO. The following search terms were used to identify eligible articles: (1) pregnancy, (2) mental disorders, (3) psychosocial problems, (4) treatment and (5) randomised controlled trials. We used subject headings and free text terms to likely retrieve all relevant articles. The search was conducted on 31 January 2020 and updated on 20 December 2021.
The results of the search strategy were exported to EndNote, after which duplicates were removed. Two authors (CK, LvR) reviewed the results on title and abstract. In case of disagreement or doubt a third reviewer was consulted (JS). Based on the criteria described below, full text articles were assessed on eligibility. When there were multiple articles from the same trial, the article with the most complete or relevant outcomes was included.