Prenatal Cigarette Exposure Hurt Children's Reading and Language, but Prenatal Marijuana Did Not
Among 131 children aged 9-12 followed from birth, prenatal cigarette exposure was linked to lower reading and language scores in a dose-dependent pattern, while prenatal marijuana exposure showed no significant relationship to either outcome.
Quick Facts
What This Study Found
Researchers examined reading and language abilities in 131 children aged 9-12 who were part of a longitudinal study tracking prenatal drug exposure from a predominantly middle-class population.
Prenatal cigarette exposure showed a dose-dependent association with lower language and reading scores, even after controlling for potential confounders. The effects were strongest on auditory-related aspects of reading, consistent with earlier findings linking prenatal cigarette exposure to altered auditory functioning.
Prenatal marijuana exposure was not significantly related to either reading or language outcomes at this age.
An additional finding: while the mother's own passive smoke exposure during pregnancy did not affect outcomes, the child's postnatal secondhand smoke exposure was associated with poorer language scores.
Key Numbers
131 children aged 9-12. Prenatal cigarette exposure: dose-dependent association with lower reading and language. Prenatal marijuana exposure: not significantly related to outcomes. Postnatal secondhand smoke: associated with poorer language scores.
How They Did This
Longitudinal study of 131 children aged 9-12 from a low-risk, predominantly middle-class sample. Prenatal exposure to marijuana and cigarettes was ascertained prospectively. Reading and language were assessed using multiple measures. Discriminant Function Analysis controlled for potential confounders.
Why This Research Matters
This study provided important comparative data: prenatal cigarette exposure, not marijuana exposure, was the substance linked to cognitive effects in this age group. The finding has implications for risk communication to pregnant women and for understanding which prenatal exposures carry the greatest developmental risk.
The Bigger Picture
This study is part of a larger longitudinal project that has followed children prenatally exposed to cannabis from birth through adolescence. While prenatal marijuana exposure has been linked to some subtle effects at other ages, the reading and language domain at ages 9-12 did not appear to be affected.
What This Study Doesn't Tell Us
Predominantly middle-class sample may not generalize to higher-risk populations. The absence of a significant marijuana association does not prove safety, as the study may have been underpowered to detect small effects. Self-reported prenatal substance use may be inaccurate.
Questions This Raises
- ?Would larger samples or different cognitive measures detect prenatal marijuana effects?
- ?Do effects emerge at later ages as cognitive demands increase?
- ?How do prenatal cigarette and marijuana effects interact in combined users?
Trust & Context
- Key Stat:
- Prenatal marijuana exposure was not significantly related to reading or language outcomes
- Evidence Grade:
- A longitudinal cohort study with prospective exposure assessment and confounder control. Good design but moderate sample size and a single developmental window.
- Study Age:
- Published in 1997. Subsequent studies from this and other cohorts have continued to track prenatal cannabis exposure effects through adolescence.
- Original Title:
- Reading and language in 9- to 12-year olds prenatally exposed to cigarettes and marijuana.
- Published In:
- Neurotoxicology and teratology, 19(3), 171-83 (1997)
- Authors:
- Fried, P A(2), Watkinson, B(2), Siegel, L S
- Database ID:
- RTHC-00059
Evidence Hierarchy
Follows a group of people over time to track how outcomes develop.
What do these levels mean? →Frequently Asked Questions
Does smoking marijuana during pregnancy affect the child's reading?
In this study, prenatal marijuana exposure was not significantly related to reading or language outcomes in children aged 9-12. Prenatal cigarette exposure, by contrast, was associated with lower scores.
Does this mean marijuana is safe during pregnancy?
Not necessarily. This study measured specific outcomes at specific ages. Other studies have found subtle effects of prenatal cannabis exposure on other cognitive domains or at different ages.
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Cite This Study
https://rethinkthc.com/research/RTHC-00059APA
Fried, P A; Watkinson, B; Siegel, L S. (1997). Reading and language in 9- to 12-year olds prenatally exposed to cigarettes and marijuana.. Neurotoxicology and teratology, 19(3), 171-83.
MLA
Fried, P A, et al. "Reading and language in 9- to 12-year olds prenatally exposed to cigarettes and marijuana.." Neurotoxicology and teratology, 1997.
RethinkTHC
RethinkTHC Research Database. "Reading and language in 9- to 12-year olds prenatally expose..." RTHC-00059. Retrieved from https://rethinkthc.com/research/fried-1997-reading-and-language-in
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.