A new study by Queen’s University researcher Susan Brogly (Surgery) has revealed that 25 per cent of women suffering from a prenatal opioid dependence were not being treated for their addiction. Using data from the Institute for Clinical Evaluative Sciences (ICES), the study also shows rising numbers of affected mother-infant pairs and associated health care costs.

“The information on health care costs are new for Canada, which goes along with the 16 fold increase in the number of mother-infant pairs affected by opioid dependence over the past decade,” says Dr. Brogly. “That is a striking finding but not new data. A larger concern is the 25 per cent of affected women that did not have an opioid agonist prescription recorded in the Ontario Drug Benefit program database.”

Opioid agonist treatment with methadone or buprenorphine is used to prevent maternal illicit opioid use and withdrawal and to improve prenatal care and pregnancy outcomes.  Methadone is predominately used in pregnant women in Ontario, largely because the form of buprenorphine used in pregnancy is not available in Canada and has to be imported from the United States under a special Health Canada program.  The long delay in getting buprenorphine can result in ongoing drug use, relapse or other complications in the pregnancy.

Many practitioners use methadone (which requires a special license in Ontario) and which may cause more severe withdrawal in the neonate. Buprenorphine, in the form used in pregnancy, can be prescribed by family physicians, obstetricians and other physicians without a special license. 

“This is an important finding because it could indicate barriers and stigma towards specific groups of women accessing care in our socialized healthcare system,” says Dr. Brogly. “More effective programming to prevent opioid dependence and prescription drug misuse is clearly needed and buprenorphine needs to be more readily available for pregnant women.”

In the study, Dr. Brogly revealed the number of infants born to opioid-dependent women in Ontario rose from 46 in 2002 to almost 800 in 2014. In addition rates of preterm birth, birth defects, still birth and infant mortality were higher than those reported for the Ontario newborn population.  All of these complications translate into significant increased costs to the system.

“The next steps are to confirm whether there are barriers to care, to try to tease out which exposures and what period of exposure in gestation causes poor birth outcomes in this population,  to identify longer term outcomes of the mothers and infants, and to prevent substance in young women,” says Dr. Brogly. “These data can be used to argue for more treatment options, including buprenorphine, and drug treatment programs tailored to women and their children. Support should also be given to the mothers and their children beyond the immediate post-partum period to facilitate the growth of healthy families and children.”

The research was conducted in conjunction with Queen’s professors Greg Davies (Obstetrics and Gynaecology)), Adam Newman (Family Medicine), Ana Johnson (Public Health Sciences), Kimberly Dow (Pediatrics) and University of Toronto professor Suzanne Turner (Family Medicine).

It was recently published in the Journal of Obstetrics and Gynaecology Canada.

ICES is a not-for-profit research institute encompassing a community of research, data and clinical experts, and a secure and accessible array of Ontario's health-related data. There is a branch of ICES located at Queen’s University.