Maternal and infant outcomes following third trimester exposure to marijuana in opioid dependent pregnant women maintained on buprenorphine.

Background: To determine whether maternal and infant outcomes are associated with exposure to marijuana during the third trimester in a population of opioid dependent pregnant women maintained on buprenorphine.

Methods: This retrospective cohort study of 191 maternal-infant dyads exposed to buprenorphine during pregnancy examines a variety of variables including gestational age, birthweight, method of delivery, Apgar scores at one and five minutes, duration of infant hospital stay, peak neonatal abstinence syndrome (NAS) score, duration of NAS and incidence of pharmacologic treatment of NAS in infants exposed to marijuana during the third trimester as compared to infants not exposed to marijuana during the third trimester.

Results: Analyses failed to support any significant relationship between marijuana use in the third trimester and a variety of maternal and infant outcomes. Two important variables - the likelihood of requiring pharmacologic treatment for NAS (27.6% in marijuana exposed infants vs. 15.7% in non-marijuana exposed infants, p=0.066) and the duration of infant hospital stay (7.7days in marijuana exposed infants vs. 6.6days in non-exposed infants, p=0.053) trended toward significance.

Conclusions: Preliminary results indicate that marijuana exposure in the third trimester does not complicate the pregnancy or the delivery process. However, the severity of the infant withdrawal syndrome in the immediate postnatal period may be impacted by marijuana exposure. Because previous study of prenatal marijuana exposure has yielded mixed results, further analysis is needed to determine whether these findings are indeed significant.