Objectives: To determine the psychological and behavioural effects of the COVID-19 pandemic on a Canadian cohort of individuals during pregnancy and the postpartum period.Methods: In 2020, individuals between 20 weeks gestation and 3 months postpartum receiving maternity care from an urban Canadian clinic were invited to complete a questionnaire. The purpose-built questionnaire used validated scales including the Medical Outcomes Study Social Support Survey (MOS), Depression, Anxiety, and Stress Scale (DASS-21), Edinburgh Postnatal Depression Scale (EPDS), and questions from a SARS study.Results: One hundred nine people completed the questionnaire (response rate, 55%) of whom 57% (n = 62) were postpartum. Most respondents (107, 98%) were married and had completed post-secondary education (104, 95%). Despite these protective factors, moderate to severe levels of depression (22%), anxiety (19%) and stress (27%), were recorded using the DASS-21, and 25% of participants (26) had depression (score >= 11) using the EPDS.Despite high social support in all MOS domains (median scores 84-100), a majority of participants reported loneliness (69, 67%) and were nearly or totally housebound (65, 64%). About half of participants worried about themselves (50, 46.3%) or their baby (59, 54%) contracting COVID-19, while the majority postponed (80, 74.1%) and cancelled (79, 73.2%) prenatal appointments. Being homebound or feeling lonely / lacking support were significant risk factors for psychological distress (P = 0.02) whereas exercise and strong social support were protective (P < 0.05).Conclusion: Pregnant and postpartum individuals experienced moderate to severe depression, anxiety, and stress during the COVID-19 pandemic. Exercise and strong social support were protective. Health care provider enquiry of home circumstances and activity may identify individuals needing enhanced supports.