The importance of opioid agonist treatment during and after pregnancy

Pregnancy and the first year after birth are especially important periods for the health and wellbeing of both women* and their babies. For women who are dependent on opioids, opioid agonist treatment including methadone or buprenorphine is the recommended care during and after pregnancy. Staying on treatment helps prevent a return to illicit opioid use and reduce the risk of overdose. Engagement in treatment can also support access to antenatal and postnatal care and provide stability during a period of major physical, emotional, and social change.

New population-based evidence on engagement in opioid agonist treatment during and after pregnancy

Researchers at the National Drug and Alcohol Research Centre, UNSW conducted a series of population-based studies examining engagement in opioid agonist treatment during and after pregnancy following the endorsement of buprenorphine for use during pregnancy. Studies analysed data routinely collected in New South Wales from 2004 to 2021, including records of pregnancies resulting in a birth, authorities to prescribe methadone and buprenorphine, hospital admissions, and contacts with other health services.

Overall, the findings are encouraging, demonstrating strong engagement in care, while highlighting groups who may benefit from targeted support to remain in treatment.

Trends in opioid agonist treatment during pregnancy: In the first study of 5,212 women with a history of treated opioid dependence, three in four received treatment during pregnancy, and the number using buprenorphine increased substantially between 2005 and 2021.

Treatment retention during pregnancy: Among 4,472 women receiving treatment during pregnancy, the second study found that over eight in ten remained in treatment until childbirth.

Treatment retention after pregnancy: Among 3,393 women on treatment at the time of birth, the third study found that nearly eight in ten continued treatment for at least a year after birth.

The second and third studies also identified groups who were more likely to discontinue treatment before birth or during the first postpartum year. These included women who started treatment after becoming pregnant rather than before pregnancy, those receiving buprenorphine rather than methadone, women who initiated treatment in prison, and women with mental health conditions.

Meaning of this new evidence

For opioid dependence during pregnancy, treatment with methadone or buprenorphine is safer than no treatment and should be prioritised. The new evidence is encouraging: most women who would benefit from opioid agonist treatment were receiving it during pregnancy, and remained engaged in treatment throughout pregnancy and the first postpartum year. Service providers should be aware that women who start treatment during pregnancy, those receiving buprenorphine, women in custody, and those with mental health conditions may require additional support to remain in treatment.

To view interactive results from three studies, please click the following link.

^{*Please note that although we use terms which describe gender throughout the content, including woman, mother, and maternal, our focus is on the biological sex. The information provided here should be considered inclusive of individuals who are pregnant or who have given birth but may not identify as women.}