There is little knowledge of how women who use and are in treatment for using drugs in the perinatal period experience multidisciplinary services prenatally. This study used qualitative longitudinal methods to explore women’s experiences of care in four sites in England and Scotland. Thirty-six women who used and were in treatment for drug use (opioid, stimulants, and benzodiazepines) were recruited via maternity services. Framework analysis was used to manage the data and data were coded thematically. The profile of research participants included experiences of a range of cooccurring physical and mental health problems. Most women for whom this was not their first maternity, had had previous children removed from their care. The findings focus on women’s experiences of surveillance and uncertainty surrounding referrals to social services, social work assessments and possible removal of babies. Research participants reported managing the conceptual entanglement of treatment for opioid use with illicit drug use. Participants described being subject to multi-agency monitoring and there were few examples of trauma-informed care at the point of delivery. Findings have implications for how multi agency services engage with women who use drugs and call for approaches that are responsive to their needs and those of their babies.