It is well known that pregnant women can suffer from maternal distress. Effective interventions can contribute to optimize antenatal maternal emotional wellbeing. A carefully developed intervention is an essential predecessor to intervention research. Intervention research can be practically and ethically challenging when the evaluations are embedded into the care of pregnant women and when the researcher is also a midwifery practitioner. Intervention research can also be methodologically challenging when non-randomized pre–post studies with a sequential control and experimental group are not the preferred method to evaluate public health interventions. There is no consensus on how different design features are related to the strength of evidence. This case study provides an insight into the practicalities and considerations of performing a non-randomized pre–post study aiming to provide reasonable evidence of intervention effect—through the eyes of a postdoctoral student.