Infants exposed to cannabis in utero showed no difference in well-child visits, ER use, or developmental delay at age 3 compared to unexposed infants on Medicaid.
Parents, obstetricians, pediatricians, and researchers studying prenatal substance exposure.
No developmental difference at age 3
What the researchers found
Among 4,270 Medicaid-insured infants with meconium drug screening, cannabis-exposed infants (n=1,671) had similar rates of well-child care attendance, emergency department visits, and developmental delay diagnoses at 3 years compared to unexposed infants (n=2,599). At 2 years, cannabis-exposed infants actually had lower odds of developmental delay, though this difference disappeared by year 3.
Why it matters
This is one of the largest studies using objective exposure measurement (meconium testing) rather than self-report. The null findings at 3 years are reassuring but do not rule out longer-term effects that may emerge later in childhood.
The numbers in context
7,240 infants screened, 5,448 linked to Medicaid (75%). 1,671 cannabis-exposed, 2,599 unexposed. No difference in well-child visits or ED encounters at 2 years. No difference in developmental delay at 3 years.
How the study worked
Retrospective cohort linking meconium drug screen results from a university hospital (2014-2022) with North Carolina Medicaid claims. Cannabis-exposed infants (positive for cannabis only) were compared to substance-unexposed infants using regression models.
What this study cannot tell us
Only Medicaid-insured infants, who may differ from privately insured populations. Meconium screening only detects third-trimester exposure and cannot quantify amount used. Developmental delay diagnosed via claims codes may miss subtle delays. Follow-up limited to 3 years.
How to read the evidence
Large retrospective cohort with objective exposure measurement, but limited to Medicaid population and 3-year follow-up.
When this study was published
2026 study using 2014-2022 screening data.
The bigger picture
While these short-term findings are encouraging, they do not address potential effects on cognitive development, behavior, or academic performance that may only become apparent at school age. The study adds important data to the ongoing debate about prenatal cannabis exposure.
Questions still open
- Would longer follow-up through school age reveal differences that are not yet apparent? Does the amount or timing of prenatal cannabis exposure matter for developmental outcomes?
Common questions
Does prenatal cannabis exposure cause developmental delays?
How was cannabis exposure measured?
Read the original research
Health Care Utilization and Developmental Delay Among Infants Exposed to Cannabis In Utero.
Academic pediatrics, 26(3), 103224
Citation
Raffa, Brittany J; Lanier, Paul; Yang, Yumei; Lin, Feng-Chang; Seashore, Carl; Schilling, Samantha. (2026). Health Care Utilization and Developmental Delay Among Infants Exposed to Cannabis In Utero.. Academic pediatrics, 26(3), 103224. https://doi.org/10.1016/j.acap.2026.103224
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