Testing Newborn Meconium Reveals Cannabis Exposure That Mothers Don't Report
Meconium testing detected prenatal cannabis and alcohol exposure that maternal self-reports missed, though sample sizes for positive cannabis results were small.
Quick Facts
What This Study Found
This study compared what mothers reported about their substance use during pregnancy with what objective testing of their newborns' meconium (first stool) actually revealed.
For tobacco, meconium cotinine testing agreed well with maternal self-reports (Kappa = 0.79), and meconium testing actually predicted neonatal consequences of tobacco exposure better than self-reports alone.
For cannabis and alcohol, the story was different. Agreement between self-reports and meconium testing was low for both alcohol (Kappa = 0.13) and cannabis (Kappa = 0.30). Notably, the highest levels of alcohol metabolites in meconium were found in babies whose mothers denied drinking, suggesting significant underreporting of prenatal alcohol exposure.
Among 645 meconium samples collected from 724 mothers across all maternity units in Rouen, France, over two 5-week periods, polyconsumption (using multiple substances) was actually less common than expected based on meconium testing. An interesting finding in dizygotic twins showed that fetal exposure to substances can differ substantially even between twins sharing the same pregnancy.
Key Numbers
724 mothers, 645 meconium samples. Tobacco agreement: Kappa = 0.79. Alcohol agreement: Kappa = 0.13. Cannabis agreement: Kappa = 0.30. Total cannabinoid-positive meconium samples were small in number.
How They Did This
Cross-sectional study of 724 mothers and 645 meconium samples collected within 72 hours of delivery across all maternities in Rouen, Normandy. Maternal self-reports used the Addiction Severity Index (5th edition). Meconium was tested for cotinine (tobacco), ethyl-glucuronide (alcohol), and cannabinoid metabolites.
Why This Research Matters
Prenatal substance exposure has significant effects on neonatal health and child development. If mothers underreport cannabis and alcohol use during pregnancy, clinicians relying solely on self-reports will miss exposures. Meconium testing provides an objective alternative that captures third-trimester exposure.
The Bigger Picture
The discrepancy between self-reported and objectively measured prenatal substance exposure has implications for both clinical care and research. Studies relying on maternal self-reports may systematically underestimate prenatal cannabis and alcohol exposure rates, leading to underestimation of associated health effects.
What This Study Doesn't Tell Us
The number of cannabis-positive and alcohol-positive meconium samples was small, limiting statistical precision for these substances. Meconium reflects only third-trimester exposure and may miss earlier pregnancy use. Cultural factors in France may affect reporting patterns differently than in other countries.
Questions This Raises
- ?Should routine meconium screening be implemented in clinical practice?
- ?Would non-judgmental screening environments improve maternal self-reporting accuracy?
- ?How does first-trimester cannabis exposure (missed by meconium) compare in neonatal effects to third-trimester exposure?
Trust & Context
- Key Stat:
- Maternal self-reports and meconium testing agreed poorly for cannabis (Kappa = 0.30) and alcohol (Kappa = 0.13)
- Evidence Grade:
- Well-designed cross-sectional study with objective biomarker validation across all maternities in a defined region. Moderate because cannabis-positive sample sizes were small.
- Study Age:
- Published in 2017, with data from August 2010 and August 2011.
- Original Title:
- Assessment of tobacco, alcohol and cannabinoid metabolites in 645 meconium samples of newborns compared to maternal self-reports.
- Published In:
- Journal of psychiatric research, 90, 86-93 (2017)
- Authors:
- Lamy, Sandrine, Hennart, Benjamin, Houivet, Estelle, Dulaurent, Sylvain, Delavenne, Heloise, Benichou, Jacques, Allorge, Delphine, Marret, Stéphane, Thibaut, Florence
- Database ID:
- RTHC-01425
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Do mothers accurately report cannabis use during pregnancy?
This study found poor agreement between maternal self-reports and objective meconium testing for cannabis (Kappa = 0.30), suggesting significant underreporting. Self-reports were more reliable for tobacco use.
What is meconium testing?
Meconium is a newborn's first stool, which accumulates during pregnancy and contains metabolites of substances the fetus was exposed to during the third trimester. Testing it provides an objective measure of prenatal exposure independent of what the mother reports.
Read More on RethinkTHC
Cite This Study
https://rethinkthc.com/research/RTHC-01425APA
Lamy, Sandrine; Hennart, Benjamin; Houivet, Estelle; Dulaurent, Sylvain; Delavenne, Heloise; Benichou, Jacques; Allorge, Delphine; Marret, Stéphane; Thibaut, Florence. (2017). Assessment of tobacco, alcohol and cannabinoid metabolites in 645 meconium samples of newborns compared to maternal self-reports.. Journal of psychiatric research, 90, 86-93. https://doi.org/10.1016/j.jpsychires.2017.02.012
MLA
Lamy, Sandrine, et al. "Assessment of tobacco, alcohol and cannabinoid metabolites in 645 meconium samples of newborns compared to maternal self-reports.." Journal of psychiatric research, 2017. https://doi.org/10.1016/j.jpsychires.2017.02.012
RethinkTHC
RethinkTHC Research Database. "Assessment of tobacco, alcohol and cannabinoid metabolites i..." RTHC-01425. Retrieved from https://rethinkthc.com/research/lamy-2017-assessment-of-tobacco-alcohol
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.