Management of opioid dependence during pregnancy
Centre for Alcohol and Other Drugs, 2014
Patients with opioid dependence who are considering pregnancy or are pregnant should be urgently referred to a specialist antenatal and drug and alcohol treatment service to assist with management in planning pregnancy, during pregnancy and the postpartum.
Potential harms of unmanaged opioid use in pregnancy result from overdose, withdrawal and injection harms; they include intrauterine growth restriction, premature rupture of membranes, placental abruption, stillbirth, and maternal and neonatal infections. Additional risks include other drug use (eg alcohol, tobacco), partner violence, unstable accommodation, poverty, mental health problems and sex work that can increase pregnancy risks and result in poor antenatal attendance. Opioid withdrawal is not recommended because of concerns about relapse, poor antenatal attendance and the risk of premature labour and miscarriage.
Medication-assisted treatment of opioid dependence (MATOD) is the standard recommendation for opioid dependence during pregnancy. Benefits of MATOD include improved maternal health, attendance at antenatal care, decreased miscarriage and neonatal loss, higher birth weight babies, longer gestations and increased likelihood of the infant being discharged into the patient’s care.
Most infants exposed to buprenorphine or methadone develop a withdrawal syndrome (neonatal opioid withdrawal syndrome [NOWS]). Reassure patients that severity of NOWS is not related to maternal buprenorphine or methadone dose. The prevalence, severity and duration of clinically significant NOWS appear to be less with buprenorphine compared to methadone.
Methadone and sublingual buprenorphine (both buprenorphine alone and the combination products with naloxone) can be prescribed during pregnancy and breastfeeding. For patients who are not already on MATOD, buprenorphine may be the preferred first-line treatment, particularly because the risk of NOWs is less with buprenorphine compared to methadone treatment. Modified-release buprenorphine (as a subcutaneous injection) can be prescribed provided a harm–benefit analysis is favourable for the patient and baby.
For pregnant patients who are not stable on sublingual buprenorphine, switching to modified-release buprenorphine or methadone may be considered. Switching from methadone to buprenorphine is generally not advised in pregnancy because of the risk of precipitated withdrawal. Seek specialist advice on switching treatments from a substance use in pregnancy service.
Metabolic changes in pregnancy may require increases in the dose of buprenorphine or methadone (more so for methadone than buprenorphine).
The onset of NOWS is usually 48 to 72 hours after birth, but may be up to 1 week after birth. Therefore, an extended stay in hospital for the patient and their baby is recommended for observation. Nonpharmacological support for babies with NOWS (cuddling, feeding, tight wrapping in a blanket, low stimulation) is important.