The COVID-19 pandemic has led to escalations in substance use, including alcohol consumption. Of particular concern are the potential impacts during the postpartum period, a time of heightened vulnerability to stress and potential transmission of the negative sequelae of substance use to offspring. However, postpartum alcohol consumption during the COVID-19 pandemic has not been well characterized.

Postpartum drinking habits and COVID-19-related stress were repeatedly assessed (every two weeks for 12 weeks, and at one-, six-, and 12-months postpartum) from N = 378 individuals during the COVID-19 pandemic. Average alcohol use trajectories as well as heterogeneity in trajectories were characterized. COVID-19-related trauma symptoms and coping were examined in relation to alcohol use over time.

Average postpartum alcohol use included an initial quadratic increase from one-to-four-months postpartum, followed by a plateau between four-to-12-months. Higher (15.08%), moderate (26.90%), and lower consumption (57.90%) subgroups were identified. Endorsement of COVID-19-related trauma symptoms and using alcohol to cope with stress predicted higher consumption.

Findings suggest a potential sensitive period in establishing postpartum alcohol use patterns from one-to-four-months postpartum. Findings further suggest that postpartum alcohol use is heterogenous and that individual response to major traumatic stressors, like the COVID-19 pandemic, may influence emerging patterns of postpartum alcohol use.