In Denmark, cannabis was linked to one-third of neonatal withdrawal cases not involving opioids
A Danish study found that while most neonatal abstinence syndrome (NAS) cases were linked to maternal opioid use, one-third of treated neonates were not exposed to opioids, and cannabis was the most frequent non-opioid drug involved, with 9% of all NAS cases attributed to cannabis alone.
Quick Facts
What This Study Found
Among 98 neonates pharmacologically treated for NAS in eastern Denmark over 6 years, the incidence remained stable at 0.6 per 1,000 live births. One-third of treated neonates were not exposed to opioids. Cannabis was the most common non-opioid drug causing NAS, with 14% of all treated neonates exposed to cannabis and 9% exposed to cannabis as the only drug besides tobacco.
Key Numbers
447 neonates identified with relevant diagnoses; 98 pharmacologically treated for NAS; incidence: 0.6 per 1,000 live births (stable over 6 years); one-third not exposed to opioids; 14% exposed to cannabis; 9% exposed to cannabis as only drug (plus tobacco)
How They Did This
Historical multicentre cohort study of neonates treated for NAS between 2013 and 2018 in eastern Denmark. The Danish National Patient Register identified 447 neonates with relevant diagnoses; medical record review confirmed 98 were pharmacologically treated for NAS.
Why This Research Matters
NAS is typically associated with opioid exposure, but this study found a substantial proportion linked to cannabis. This challenges the common assumption that cannabis withdrawal does not affect newborns and suggests healthcare providers should monitor for NAS after prenatal cannabis exposure.
The Bigger Picture
While opioid-related NAS has received most attention, this study adds to emerging evidence that other substances, including cannabis, may cause neonatal withdrawal requiring medical treatment. As cannabis use during pregnancy increases, this finding has growing clinical relevance.
What This Study Doesn't Tell Us
Limited to eastern Denmark, which may not reflect other populations. Relatively small number of cases (98 treated). Tobacco exposure was common and could confound cannabis-specific effects. Retrospective design relies on medical record accuracy.
Questions This Raises
- ?What are the specific symptoms of cannabis-related NAS compared to opioid-related NAS?
- ?Do cannabis-related NAS cases require different treatment approaches?
- ?Is the mechanism truly withdrawal, or could it be a direct pharmacological effect?
Trust & Context
- Key Stat:
- 9% of neonatal withdrawal cases linked to cannabis as the only drug (plus tobacco)
- Evidence Grade:
- Moderate: multicentre cohort with national registry data and medical record verification, but small case count and retrospective design.
- Study Age:
- 2026 publication analyzing Danish data from 2013-2018.
- Original Title:
- The Incidence of Neonatal Abstinence Syndrome Remained Stable in Eastern Denmark From 2013 to 2018 and Was Sometimes Associated With Cannabis.
- Published In:
- Acta paediatrica (Oslo, Norway : 1992) (2026)
- Database ID:
- RTHC-08688
Evidence Hierarchy
Looks back at existing records to find patterns.
What do these levels mean? →Frequently Asked Questions
Can cannabis cause withdrawal symptoms in newborns?
This study found that 9% of neonates treated for neonatal abstinence syndrome were exposed only to cannabis (and tobacco). The authors recommend healthcare professionals be aware of NAS after prenatal cannabis exposure.
How common is neonatal abstinence syndrome in Denmark?
The incidence was 0.6 per 1,000 live births, stable over the 6-year study period. Most cases were linked to maternal opioid analgesics, but a third involved non-opioid substances.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-08688APA
Vestermark, Vibeke; Kjærbye-Thygesen, Anette; Kesmodel, Ulrik Schiøler. (2026). The Incidence of Neonatal Abstinence Syndrome Remained Stable in Eastern Denmark From 2013 to 2018 and Was Sometimes Associated With Cannabis.. Acta paediatrica (Oslo, Norway : 1992). https://doi.org/10.1111/apa.70443
MLA
Vestermark, Vibeke, et al. "The Incidence of Neonatal Abstinence Syndrome Remained Stable in Eastern Denmark From 2013 to 2018 and Was Sometimes Associated With Cannabis.." Acta paediatrica (Oslo, 2026. https://doi.org/10.1111/apa.70443
RethinkTHC
RethinkTHC Research Database. "The Incidence of Neonatal Abstinence Syndrome Remained Stabl..." RTHC-08688. Retrieved from https://rethinkthc.com/research/vestermark-2026-the-incidence-of-neonatal
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.