Verbal and nonverbal memory in school-aged children born to opioid-dependent mothers

Background: The potential long-term developmental effects of prenatal methadone and buprenorphine exposure during pregnancy are still largely unknown. Aims: We investigated memory function in school-aged children of women enrolled in opioid maintenance therapy (OMT) during pregnancy. Study design: Prospective longitudinal cohort study. Subjects: Participants included 41 children (aged 9-11 years), 20 of which had histories of prenatal methadone or buprenorphine exposure. Outcome measures: Verbal and non-verbal memory function was assessed using four subtests from the Test of Memory and Learning - Second edition (TOMAL-2). Results: The OMT group scored lower on both the two non-verbal as well as the two verbal memory tasks, all p-values <.05. Group differences remained for three out of the four subtests after controlling for general IQ. Including maternal tobacco use during pregnancy increased the explanatory power of the model, R-2 change of 0.07, p = .04. Conclusions: Children prenatally exposed to methadone or buprenorphine had significantly lower memory performance, however, this association may in part be explained by maternal tobacco use during pregnancy. Consequently, smoking cessation programs should be systematically integrated into opioid maintenance therapy programs for pregnant women.