BACKGROUND-Methadone, a full mu-opioid agonist, is the recommended treatment for opioid dependence during pregnancy. However, prenatal exposure to methadone is associated with a neonatal abstinence syndrome (NAS) characterized by central nervous system hyperirritability and autonomic nervous system dysfunction, which often requires medication and extended hospitalization. Buprenorphine, a partial mu-opioid agonist, is an alternative treatment for opioid dependence but has not been extensively studied in pregnancy.

The aim of the present study was to estimate the prevalence of unintended pregnancy and its three subtypes (mistimed, unwanted, ambivalent) among opioid-abusing women. In the general population, 31–47% of pregnancies are unintended; data on unintended pregnancy in opioid- and other drug-abusing women are lacking. Pregnant opioid-abusing women (N=946) screened for possible enrollment in a multi-site randomized controlled trial comparing opioid maintenance medications completed a standardized interview assessing sociodemographic characteristics, current and past drug use, and pregnancy intention. Almost 9 of every 10 pregnancies were unintended (86%), with comparable percentages mistimed (34%), unwanted (27%), and ambivalent (26%). Irrespective of pregnancy intention, more than 90% of the total sample had a history of drug abuse treatment, averaging more than 3 treatment episodes. Interventions are sorely needed to address the extremely high rate of unintended pregnancy among opioid-abusing women. Drug treatment programs are likely to be an important setting for such interventions.