PurposeThis study aimed to understand the impact of social media on postpartum mothers’ parenting confidence among participants in the Moms on Media Study, an experimental mixed methods study.MethodsWe used an embedded mixed methods approach among a sample of postpartum mothers of infants aged 0–6 months who were randomly assigned to view either body focused social media posts (experimental group, n = 65) or infant feeding tips (control group, n = 67) over a 5 day period. ANCOVA was used to examine differences between the experimental and control group on parenting confidence at post-intervention and 1 month follow-up. A subsample of mothers in the experimental group (n = 20) took part in semi-structured interviews post-intervention. Thematic analysis was used to identify themes and subthemes generated from the data.ResultsCounter to expectations, ANCOVA results show that at post-intervention mothers who viewed the body-focused posts scored significantly higher for total parenting confidence (mean difference = 1.36), parenting confidence (mean difference = 0.89), and support confidence (mean difference = 0.53). These differences in total parenting confidence (mean difference = 2.03), parenting confidence (mean difference = 1.40) and support confidence (mean difference = 0.50) were sustained at 1-month follow up. No significant differences were found for child development confidence between the experimental and control group at either post-intervention or 1-month follow-up. Qualitative analysis revealed that many mothers described feeling better about their parenting after viewing body-focused social media posts where they felt mothers were overly focused on their own image versus spending time with their child as a “good” mother “should.”ConclusionsBody-focused social media posts may lead to downward social comparison among postpartum mothers. Findings may help inform interventions or clinical care focused on healthy social media exposure and use during the postpartum period.