Objective Intimate partner violence is a global health concern with a wide range of consequences. This article aims to assess the association between intimate partner violence among pregnant women and register-based psychiatric diagnoses, taking risk factors and non-responders into account. Design A cross-sectional study utilising Danish registers Setting Denmark Population 28,697 pregnant women Methods Pregnant women attending antenatal care in the Region of Southern Denmark, or the Capital Region, took part in the routinely collected PROdata questionnaire containing the Abuse Assessment Screen(AAS) during their first trimester, from December 2019 to September 2022. After questionnaire collection, data was linked with multiple Danish registers, including the Danish Psychiatric Treatment Register. On an individual level, the psychiatric diagnoses were detected in the registers, and if the woman had a psychiatric diagnosis within the last five years, she was grouped as either moderate or severe psychiatric diagnoses. Main Outcome Measures Moderate or severe psychiatric diagnoses Results In total, 28,697 women received the PROdata questionnaire, and 23,768 (82,8%) responded to the AAS. The prevalence of screening positive for IPV was 5.34% (n=1269). We found a strong association between intimate partner violence and both moderate and severe psychiatric diagnoses with an increased adjusted OR of 3.01 (95% CI: 2.51, 3.60) and 4.34 (95% CI: 3.27, 5.85), respectively, compared with women with no psychiatric diagnoses. Conclusion Our results show a strong link between Intimate Partner Violence and psychiatric diagnoses among pregnant women. It also provides important information on risk factors for violence and characteristics of non-responders to digital screening.