Plain English SummaryMental disturbances are common during pregnancy. Most of the time, these are normal.However, these disturbances may become serious and lead to self-harm and suicide. In this study, we estimated the proportion of pregnant women who had depression and idea of self-harming during pregnancy.Respondents were pregnant women admitted to two large hospitals for the childbirth.They answered a list o questions about the thought of self-harm and attempts of self-harm during the present as well as past pregnancies.Respondents included 475 pregnant women. Of them, 3.1% reported that "the thought of self-harming has occurred to them during last seven days quite a lot (0.8%) or sometimes"(2.3%). Four (0.8%) pregnant women reported that they actually did it to some extent. Of the 475 pregnant women included in the study, 126 (26.5%) had symptoms of anxiety/depression. Level of education seemed to have an association with anxiety and depression. When women reported that they had thought of self-harm prior to pregnancy, they were about 6.4 times more likely to have depression/anxiety during the pregnancy.Adding a simple screening question (as we used in this study) during the initial pregnancy assessment to detect history of suicidal thoughts will be helpful in identification of highrisk mothers for depression and suicide.Reported suicidal ideation prior to pregnancy had a OR of 6.4 (95% CI 2.3-17.5). ConclusionsBased on our data, we conservatively estimate around 3000 ISH annually in Sri Lanka, which should be considered as a high priority for an urgent intervention.