IMPORTANCE: Pregnant individuals seeking information about the safety of prenatal cannabis use may view budtenders (individuals who work at cannabis retailers) as a trusted source of information. However, the recommendations that budtenders provide to pregnant individuals considering cannabis use are unknown.

OBJECTIVE: To characterize how budtenders respond to questions about the safety of blunt, tobacco, and cannabis use during pregnancy, and to evaluate whether advice varied by indication for use or by whether the retailer provided delivery.

DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study of California cannabis retailers, mystery shoppers posed as pregnant individuals looking for advice about the safety of prenatal substance use. Telephone calls with randomly selected licensed storefront retailers were conducted from February 26, 2024, to January 28, 2025.

EXPOSURES: Mystery shoppers followed 2 versions of a script (mental health vs no mental health indications for use) with questions about the safety of prenatal blunt, tobacco, and cannabis use.

MAIN OUTCOMES AND MEASURES: The primary outcome was retailers' responses about the safety of prenatal blunt, tobacco, and cannabis use. Secondary outcomes included product recommendations, opinions on safer vs more harmful modes of prenatal cannabis use, and whether to speak with a physician.

RESULTS: Of the 505 employees at selected retailers (ie, budtenders), 79.6% (95% CI, 74.8%-83.7%) said prenatal blunt use was unsafe, 79.2% (95% CI, 74.4%-86.4%) said prenatal tobacco use was unsafe, and 40.4% (95% CI, 35.1%-45.9%) said prenatal cannabis use was unsafe. More advised that prenatal cannabis use was safe (20.6%; 95% CI, 16.0%-26.1%) vs blunts (0.8%; 95% CI, 0.2%-2.9%) or tobacco (0.8%; 95% CI, 0.2%-2.9%) or stated that they could not give advice about the safety of prenatal cannabis (19.8%; 95% CI, 15.3%-25.2%) vs tobacco (14.3%; 95% CI, 10.5%-19.2%). Only 5.7% (95% CI, 4.0%-8.1%) mentioned store or product warnings. Budtender recommendations included low- or no-tetrahydrocannabinol cannabis products, harm reduction (eg, use less frequently), and noncannabis strategies (eg, mindfulness). Edibles were most endorsed as safe, while smoking was most endorsed as harmful. Overall, 44.0% (95% CI, 37.3%-50.8%) recommended speaking to a physician before prompting and 46.1% (95% CI, 39.4%-53.0%) after prompting. Responses were generally similar regardless of stated indication for use or delivery service availability.

CONCLUSIONS AND RELEVANCE: In this cross-sectional study, most budtenders advised against prenatal blunt and tobacco use. Fewer advised against prenatal cannabis use, highlighting the need for more visible, effective warnings and mandatory budtender education covering risks of prenatal cannabis use.