Objective: This review aimed to identify if heterogeneity exists across outcomes measured and reported in treatment studies targeting perinatal individuals with Generalized Anxiety Disorder (GAD). Design: Scoping review. Setting: Existing literature that evaluates the effectiveness of interventions for GAD during the perinatal period (i.e., pregnant and postpartum). Methods: Studies were eligible if: 1) they were English from the years 2011 to 2021; 2) participants were in the perinatal period with a GAD diagnosis; and 3) the aim of the intervention was to treat GAD during the perinatal period. Three bibliographic databases were searched. Two reviewers independently screened studies for eligibility. Study characteristics and data (e.g., outcomes, OMIs used) were extracted. Main outcome measures: Outcome measures are not required for this type of study design. Results: Of the 4424 records identified, 4 studies were included. The outcomes from the four studies were mapped to one of five core areas in Dodd et al.’s (2018) research outcome framework. A total of 10 distinct outcomes were captured across the 4 studies. Anxiety symptoms, the most common outcome, employed three different OMIs. Notably, the majority of outcomes fell within the physiological/clinical core area, indicating a dearth of patient-centered outcomes in the literature. Conclusions: This review highlights outcome and OMI variations in perinatal GAD studies. To improve synthesis, reproducibility, and comparability among treatment studies, future research in perinatal GAD treatment should adopt standardized outcomes and OMIs. This standardization is essential for informing clinical practice guidelines and policies.