Why motivation may help reduce cannabis use during pregnancy

Cannabis is one of the most common substances used during pregnancy. This study examined motivation to quit cannabis use among pregnant women enrolled in a randomized controlled trial of a technology-delivered brief motivational intervention targeting sexually transmitted infection (STI) risk behaviors, including substance use. Secondary analyses used data from a clinical trial among pregnant adults who screened positive for STI risk behavior (e.g., sexual behavior and alcohol/drug use risk during pregnancy). Four subscales (autonomous, introjected, external, and amotivation) from the Treatment Self-Regulation Questionnaire assessed motivation for not using cannabis and the timeline follow-back assessed cannabis use at baseline, 2-month, and 6-month follow-up during pregnancy. Mixed logistic regression and negative binomial regression investigated the relationship between motivation and cannabis use (Y/N) and cannabis use days, respectively, with a generalized estimating equations approach after adjusting for age and marital status. Of 176 participants (mean age: 30.2 [standard deviation = 5.0]; 26% Black), n = 62 (35.2%) reported cannabis use during pregnancy. Participants with cannabis use during pregnancy were more likely to be younger, Black, and have lower socioeconomic status than those with no cannabis use. Higher autonomous, introjected, and amotivation scores were associated with lower odds of cannabis use (p = 0.0003, p = 0.0033, p = 0.0307, respectively). Higher autonomous, introjected, and external regulation scores were associated with fewer average cannabis use days (p = 0.0013, p = 0.0035, p = 0.005, respectively). Higher levels of motivation are associated with less cannabis use during pregnancy. Given psychosocial barriers to treatment, these findings may support delivery of brief technology-delivered motivational interventions to reduce prenatal cannabis use.