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One in 20 babies born in Ontario hospitals have prenatal opioid exposure: study


A new study published in JAMA Network Open found that opioid use in pregnancy is common in Ontario, with one in 20 babies from hospital births exposed to opioids in utero, according to researchers at ICES, a non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues, and The Hospital for Sick Children (SickKids).

The study included data housed at ICES for over 700,000 hospital births in Ontario from 2014 to 2019. It is one of the most comprehensive Canadian studies to estimate the rate and type of prenatal opioid exposure.

“Opioid use in pregnancy remains high despite seeing reductions in overall prenatal opioid exposure in Ontario over time. While the long-term implications of exposure on infants is not clear, these findings highlight the need for pre- and post-natal comprehensive care to support both mothers and infants,” says Dr. Astrid Guttmann, senior author of the study, chief science officer at ICES, and staff paediatrician and senior associate scientist, Child Health Evaluative Sciences at SickKids.

The study looked at 701,896 hospital births, of which 37,415 (5.3 per cent) had prenatal opioid exposure. The annual prevalence of prenatal opioid exposure dropped from 6.1 per cent in 2014 to 4.5 per cent in 2019.

“These declines were largely driven by decreases in opioid analgesic dispensing, particularly among women prescribed opioid analgesics for less than 30 days, which may reflect uptake of more conservative opioid prescribing guidelines,” says Andi Camden, lead author of the study, PhD Candidate at the Dalla Lana School of Public Health and student at ICES.

Opioid agonist therapy (OAT) is an effective treatment for addiction to opioid drugs such as heroin, oxycodone, hydromorphone and fentanyl. The therapy involves taking the opioid agonists methadone or buprenorphine, which prevents withdrawal and reduces cravings for opioids.

While rates of OAT remained stable overall, differences emerged in the type of therapy used. Increased use of buprenorphine and decreased use of methadone reflect changes in recommended therapy during pregnancy.

The researchers found the rates of prenatal opioid exposure were highest among younger mothers (20-24 years) and those living in low-income neighbourhoods or rural areas of Ontario. The most common type of opioid exposure was short-term (less than 30 days) prescription opioid analgesics.

Prenatal opioid exposure was defined as maternal use of opioids and/or fetal exposure to opioids in pregnancy. The researchers identified prenatal opioid exposure using maternal prescription opioid data during pregnancy, categorized as: analgesics for pain, opioid for cough and OAT for opioid use disorder (methadone or buprenorphine); opioid-related maternal hospital records during pregnancy; newborn hospital records with neonatal abstinence syndrome; and outpatient visits for OAT.

They attempted to identify illicit opioid use based on:

  • a maternal-child record with neonatal abstinence syndrome or,
  • maternal opioid-related hospital care within pregnancy, and neither
  • maternal prescription opioid, nor
  • maternal OAT outpatient visit

This study was conducted before the COVID-19 pandemic. These methods will be used to explore the impact of COVID-19 on opioid use in pregnancy.

The study “Prevalence of Prenatal Opioid Exposure in Ontario, Canada, 2014-2019,” was published in the JAMA Network Open.

Author block: Camden A, Ray JG, To T, Gomes T, Bai L, Guttmann A.

ICES is an independent, non-profit research institute that uses population-based health information to produce knowledge on a broad range of healthcare issues. Our unbiased evidence provides measures of health system performance, a clearer understanding of the shifting healthcare needs of Ontarians, and a stimulus for discussion of practical solutions to optimize scarce resources. ICES knowledge is highly regarded in Canada and abroad, and is widely used by government, hospitals, planners, and practitioners to make decisions about care delivery and to develop policy. In October 2018, the institute formerly known as the Institute for Clinical Evaluative Sciences formally adopted the initialism ICES as its official name. For the latest ICES news, follow us on Twitter: @ICESOntario

The Hospital for Sick Children (SickKids) is recognized as one of the world’s foremost paediatric health-care institutions and is Canada’s leading centre dedicated to advancing children’s health through the integration of patient care, research and education. Founded in 1875 and affiliated with the University of Toronto, SickKids is one of Canada’s most research-intensive hospitals and has generated discoveries that have helped children globally. Its mission is to provide the best in complex and specialized family-centred care; pioneer scientific and clinical advancements; share expertise; foster an academic environment that nurtures health-care professionals; and champion an accessible, comprehensive and sustainable child health system. SickKids is a founding member of Kids Health Alliance, a network of partners working to create a high quality, consistent and coordinated approach to pediatric healthcare that is centred around children, youth and their families. SickKids is proud of its vision for Healthier Children. A Better World. For more information, please visit www.sickkids.ca. Follow us on Twitter (@SickKidsNews) and Instagram (@SickKidsToronto).


Deborah Creatura
Communications Strategist, ICES
[email protected]

Sarah Warr
Senior Communications Advisor, SickKids
[email protected]
416-813-7654 ext. 201436


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