Oddly, the Sheldon Adelson-owned Las Vegas Review Journal article announcing the campaign cites as its rationale a 17-year-old study, which found that "6-year-olds born to a mother who had smoked one joint or more daily in the first trimester displayed less ability to comprehend concepts in reading and listening — and by age 10 they had lower reading, math and spelling scores than their peers. It also found that children exposed to marijuana’s major psychoactive element — tetrahydrocannabinol, or THC — in the womb were more impulsive and less able to focus their attention than other 10-year-olds."
The study they cite looked at women "of low socioeconomic status. At the first interview, the median family income was $350 per month...At 10 years postpartum [from 1994 through 1997], the median family income was $1245 per month. Sixty-two percent of the women worked and/or studied outside of the home and, on average, they had 12.2 years of education."
Researchers found that "women who used one or more joints of marijuana per day during the first trimester were significantly more likely to be single, African-American, more hostile, drink more alcohol, and use more illicit drugs (other than marijuana) than were women who did not use marijuana during the first trimester....These same factors characterized moderate to heavy marijuana users at the third trimester of pregnancy. In addition, third trimester moderate to heavy users had significantly less education and smoked more cigarettes than abstainers."
The study concluded that, "The correlations between prenatal marijuana use and the covariates included in the analytical models were low to moderate. At 10 years, the variables with the highest correlations with prenatal marijuana use were work/school status, maternal custody of the child, and current use [not use while pregnant] of marijuana and cocaine. ...Other variables that significantly predicted more problems on the SNAP subscales included male gender, African-American race, more child hospitalizations over the past year, more siblings, poorer environment as assessed by the HOME-SF, more maternal hostility and depression, less maternal coping ability, and current maternal cigarette smoking. In addition, children who were not in maternal custody and children exposed to alcohol during the first trimester of pregnancy had more peer problems."
So it seems this is one of the many studies that were found not to properly adjust for confounding factors, as described in an October 2016 study published in the journal Obstetrics & Gynecology, "Maternal Marijuana Use and Adverse Neonatal Outcomes: A Systematic Review and Meta-analysis," which found that the moderate use of cannabis during pregnancy is not an independent risk factor for adverse neonatal outcomes such as low birth weight. Read more.
|From: Katrina Mark, Mishka Terplan, Cannabis and pregnancy:|
Maternal child health implications during a period of
drug policy liberalization, Preventive Medicine (2016)
To its credit, the Review-Journal does mention Melanie Dreher's 1994 study on Jamaican mothers which concluded that marijuana-using mothers gave birth to developmentally superior babies. The article adds: "Dreher’s study made little impression on the American College of Obstetrics and Gynecologists and the American Academy of Pediatrics. Both advise against marijuana use during pregnancy because of the studies linking it to cognitive impairment and academic underachievement. Both organizations also recommend that mothers with THC in their systems do not breastfeed."
Absent in all of these analyses is the conclusion Dreher made that the relative acceptance of marijuana in Jamaican society had much to do with her results. One can only hope that acceptance of cannabis in the US will ultimately lead to similar results.
But meanwhile, NIDA refused to fund a follow-up study on Dreher's results and Nevada's powerful alcohol distributors are battling to control the marijuana market. So don't expect a public awareness campaign on the dangers of using alcohol, or tobacco, while pregnant anytime soon, even though studies suggest those substances have a much greater effect on fetal health than cannabis.
Also see: NORML's Fact Sheet on Maternal Marijuana Use