In the Netherlands adverse perinatal outcomes are also associated with non-medical factors which vary across geographical locations. This study analyses the presence of non-medical vulnerabilities in pregnant women in two regions with high numbers of psychosocial adversity using the same definition for vulnerability in both regions. A register study was performed in 2 regions. Files from women in midwife-led care were analyzed using a standardized case report form addressing non-medical vulnerability based on the Rotterdam definition for vulnerability: measurement A in Groningen (n = 500), measurement B in South-Limburg (n = 538). Only in South-Limburg a second measurement was done after implementing an identification tool for vulnerability (C (n = 375)). In both regions about 10% of pregnant women had one or more urgent vulnerabilities and almost all of these women had an accumulation of several urgent and non-urgent vulnerabilities. Another 10% of women had an accumulation of three or more non-urgent vulnerabilities. This study showed that by using the Rotterdam definition of vulnerability in both regions about 20% of pregnant women seem to live in such a vulnerable situation that they may need psychosocial support. The definition seems a good tool to determine vulnerability. However, without considering protective factors it is difficult to establish precisely women's vulnerability. Research should reveal whether relevant women receive support and whether this approach contributes to better perinatal and child outcomes.