The three studies that evaluated interventions targeting attitudes towards substance-using pregnant women also found significant improvements among medical students. Bland et al.'s [60] before–after evaluation found moderately increased comfort levels discussing substance use issues with patients (g = 0.50, SE = 0.17, P < 0.01) and moderately improved attitudes specific to pregnant women with substance use disorders (g = 0.50, SE = 0.17, P < 0.01). There were no significant changes in medical students' attitudes towards substance use generally and people with substance use disorders. Using a prospective cohort design, Meng et al. [66] and Ramirez-Cacho et al. [68] both found that placing medical students in a specialized prenatal clinic for women with substance use disorders significantly increased their comfort levels in working with this population (g = 0.87, SE = 0.20, P < 0.001). There were few changes in overall stigmatizing attitudes towards alcoholism in general or towards pregnant women with substance use disorders; however, a small decrease in judgemental feelings towards substance-using pregnant women was detected (g = 0.38, SE = 0.20, P = 0.05).
