Pregnant women using cocaine and/or opioids had nearly 4 times higher odds of adverse newborn outcomes compared to those using only cannabis.
Maternal-fetal medicine specialists, addiction medicine providers, and neonatal care teams.
3.88x higher odds of adverse neonatal outcomes with cocaine/opioids versus cannabis-only exposure in pregnancy
What the researchers found
Among 177 pregnant women followed for addiction, those using cocaine and/or opioids (with or without cannabis) had 3.88 times higher odds of adverse neonatal outcomes compared to cannabis-only users. Surprisingly, cocaine/opioid exposure was associated with lower odds of adverse obstetrical outcomes (OR=0.39). 81.2% of the exposed group used opioids and 39.9% used cocaine.
Why it matters
Using cannabis-only users as the reference group (instead of drug-free controls) provides a more clinically relevant comparison for addiction medicine, better controlling for confounders associated with polysubstance use.
The numbers in context
177 pregnant women: 80 exposed (cocaine/opioids), 97 reference (cannabis-only). Adverse neonatal outcomes: ORconditional=3.88 (95% CI: 1.23-12.23). Adverse obstetrical outcomes: ORconditional=0.39 (95% CI: 0.17-0.88). 81.2% opioids, 39.9% cocaine in exposed group.
How the study worked
Observational study at the Addi-Vie perinatal consultation center, CHUV Lausanne, Switzerland. 80 women using cocaine/opioids (with or without cannabis) compared to 97 cannabis-only users. Inverse probability treatment weighting used for adjusted analysis.
What this study cannot tell us
Small sample from a single center. Cannabis-only reference group is not the same as a drug-free control. Cannot distinguish effects of individual substances within the exposed group. The unexpected protective obstetrical finding may reflect more intensive monitoring of higher-risk patients.
How to read the evidence
Novel reference group approach with appropriate weighting, but small sample, single center, and inability to isolate individual substance effects limit conclusions.
When this study was published
2025 publication.
The bigger picture
By using cannabis-only as the reference, this study implicitly positions cannabis as a less harmful substance during pregnancy compared to cocaine and opioids, though it does not assess cannabis versus no substance use.
Questions still open
- Why were obstetrical outcomes better in the cocaine/opioid group?
- Would outcomes differ if the reference group were substance-free women?
Read the original research
Risk of adverse obstetrical and neonatal outcomes in women consuming recreational drugs during pregnancy.
BMC pregnancy and childbirth, 25(1), 456
Citation
Kandhasamy, Sreemanjari; Lepigeon, Karine; Baggio, Stéphanie; Céline, Roulet; Ceulemans, Michael; Winterfeld, Ursula; Jenkinson, Stephen P; Francini, Katyuska; Maisonneuve, Emeline; Panchaud, Alice. (2025). Risk of adverse obstetrical and neonatal outcomes in women consuming recreational drugs during pregnancy.. BMC pregnancy and childbirth, 25(1), 456. https://doi.org/10.1186/s12884-024-07062-1
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