Marijuana use while pregnant boosts risk of children's sleep problems
Negative effects seen as much as a decade later
July 2, 2020
Science Daily/University of Colorado at Boulder
As many as 7% of moms-to-be use marijuana while pregnant, and that number is rising fast as more use it to quell morning sickness. But new research suggests such use could have a lasting impact on the fetal brain, influencing children's sleep for as much as a decade.
Use marijuana while pregnant, and your child is more likely to suffer sleep problems as much as a decade later, according to a new University of Colorado Boulder study of nearly 12,000 youth.
Published in Sleep Health: The Journal of The National Sleep Foundation, the paper is the latest to link prenatal cannabis use to developmental problems in children and the first to suggest it may impact sleep cycles long-term.
It comes at a time when -- while the number of pregnant women drinking alcohol and smoking cigarettes has declined in the United States -- It has risen to 7% of all pregnant women as legalization spreads and more dispensaries recommend it for morning sickness.
"As a society, it took us a while to understand that smoking and drinking alcohol are not advisable during pregnancy, but it is now seen as common sense," said senior author John Hewitt, director of the Institute for Behavioral Genetics at CU Boulder. "Studies like this suggest that it is prudent to extend that common sense advice to cannabis, even if use is now legal."
A landmark study
For the study, Hewitt and lead author Evan Winiger analyzed baseline data from the landmark Adolescent Brain and Cognitive Development (ABCD) study, which is following 11,875 youth from age 9 or 10 into early adulthood.
As part of an exhaustive questionnaire upon intake, participants' mothers were asked if they had ever used marijuana while pregnant and how frequently. (The study did not assess whether they used edibles or smoked pot). The mothers were also asked to fill out a survey regarding their child's sleep patterns, assessing 26 different items ranging from how easily they fell asleep and how long they slept to whether they snored or woke up frequently in the night and how sleepy they were during the day.
About 700 moms reported using marijuana while pregnant. Of those, 184 used it daily and 262 used twice or more daily.
After controlling for a host of other factors, including the mother's education, parent marital status and family income and race, a clear pattern emerged.
"Mothers who said they had used cannabis while pregnant were significantly more likely to report their children having clinical sleep problems," said Winiger, a graduate student in the Department of Psychology and Neuroscience.
Those who used marijuana frequently were more likely to report somnolence symptoms (symptoms of excess sleepiness) in their children, such as trouble waking in the morning and being excessively tired during the day.
The authors note that, while their sample size is large, the study has some limitations.
"We are asking mothers to remember if they smoked marijuana 10 years ago and to admit to a behavior that is frowned upon," said Winiger, suggesting actual rates of prenatal use may have been higher.
While the study doesn't prove that using cannabis while pregnant causes sleep problems, it builds on a small but growing body of evidence pointing to a link.
For instance, one small study found that children who had been exposed to marijuana in-utero woke up more in the night and had lower sleep quality at age 3. Another found that prenatal cannabis use impacted sleep in infancy.
And, in other previous work, Hewitt, Winiger and colleagues found that teenagers who frequently smoked marijuana were more likely to develop insomnia in adulthood.
The fetal brain on THC
Researchers aren't sure exactly how cannabis exposure during vulnerable developmental times might shape future sleep. But studies in animals suggest that THC and other so-called cannabinoids, the active ingredients in pot, attach to CB1 receptors in the developing brain, influencing regions that regulate sleep. The ABCD study, which is taking frequent brain scans of participants as they age, should provide more answers, they said.
Meantime, mothers-to-be should be wary of dispensaries billing weed as an antidote for morning sickness. According to CU research, about 70% of Colorado dispensaries recommend it for that use. But mounting evidence points to potential harms, including low birth weight and later cognitive problems. With marijuana on the market today including far higher THC levels than it did a decade ago, it's impacts on the fetal brain are likely more profound than they once were.
"This study is one more example of why pregnant women are advised to avoid substance use, including cannabis," said Hewitt. "For their children, it could have long-term consequences."
https://www.sciencedaily.com/releases/2020/07/200702153700.htm
Marijuana for morning sickness? It's not great for baby's brain
Study pinpoints how pot exposure during pregnancy can lead to problems with behavior and memory
April 9, 2019
Science Daily/Experimental Biology
With a growing number of states legalizing recreational or medical marijuana, more women are using the drug during pregnancy, in part due to its reported ability to relieve morning sickness. A new study, conducted in rats, sheds light on how cannabis exposure affects the brain of a developing fetus.
Previous research has shown children born to mothers who used marijuana during pregnancy are more likely to develop behavioral problems as well as learning and memory impairments. The new research offers further confirmation on those findings and pinpoints how the drug alters the intricate connections in nerves in the hippocampus, the brain's center for learning and memory. Understanding exactly how marijuana affects these brain connections could one day lead to interventions to reduce the damage, researchers say.
"The findings from this study will serve as an excellent premise for future interventions to restore memory in children exposed to cannabis during pregnancy, and for the first time, identify a specific mechanism by which learning and memory impairment occurs and how this impairment can be ameliorated," said Priyanka Das Pinky, a graduate student in the laboratory of Vishnu Suppiramaniam, PhD, acting associate dean for research and graduate programs at Auburn University.
Pinky will present the research at the American Society for Pharmacology and Experimental Therapeutics annual meeting during the 2019 Experimental Biology meeting, held April 6-9 in Orlando, Fla.
According to one previous analysis, the use of marijuana during pregnancy increased by 62 percent between 2002 and 2014, paralleling the rising popularity of marijuana in the adult U.S. population as a whole.
"Based on our research and the previous existing findings in the field, it can be said that using marijuana during pregnancy would not be a wise choice," said Pinky. "However, it is also notable that the observed effect in the offspring can vary according to their age and according to the trimester during which they were exposed to the drug as well as dose and route of administration of the drug."
The research team raised several groups of rats and exposed some of the females to a synthetic chemical that activates the same proteins as cannabis while they were pregnant. They used a dose equivalent to moderate-to-heavy marijuana use in humans. Examining the brains of the baby rats, they found the connections, or synapses, between the nerves in the hippocampus were reduced in those exposed to the synthetic cannabis.
Upon further examination, they found evidence that the root of the problem was a reduction in neural cell adhesion molecules (NCAM), a protein important for maintaining proper neural connection and synaptic strength. The finding suggests it may be possible to counteract marijuana's effects by increasing the NCAM, though more research is needed to understand the mechanisms involved and determine whether the findings, from studies in animals, would translate to human babies.
"It is still very early to come up with a conclusion about the possible safe use of marijuana during pregnancy," Pinky said. "More research is needed to evaluate the exact mechanism by which NCAM and/or its active form is modulating cellular effects while focusing on target specific drug development for amelioration of the observed cognitive deficits."
https://www.sciencedaily.com/releases/2019/04/190409135933.htm
Prenatal marijuana use can affect infant size, behavior
May 10, 2018
Science Daily/University at Buffalo
Smoking during pregnancy has well-documented negative effects on birth weight in infants and is linked to several childhood health problems. Now, researchers at the University at Buffalo Research Institute on Addictions have found that prenatal marijuana use also can have consequences on infants' weight and can influence behavior problems, especially when combined with tobacco use.
"Nearly 30 percent of women who smoke cigarettes during pregnancy also report using marijuana," says Rina Das Eiden, PhD, RIA senior research scientist. "That number is likely to increase with many states moving toward marijuana legalization, so it's imperative we know what effects prenatal marijuana use may have on infants."
Through a grant from the National Institute on Drug Abuse, Eiden studied nearly 250 infants and their mothers. Of these, 173 of the infants had been exposed to tobacco and/or marijuana during their mothers' pregnancies. None were exposed to significant amounts of alcohol.
Eiden found that infants who had been exposed to both tobacco and marijuana, especially into the third trimester, were smaller in length, weight and head size, and were more likely to be born earlier, compared to babies who were not exposed to anything. They also were more likely to be smaller in length and weight compared to babies exposed only to tobacco in the third trimester. The results were stronger for boys compared to girls.
"We also found that lower birth weight and size predicted a baby's behavior in later infancy," Eiden says. "Babies who were smaller were reported by their mothers to be more irritable, more easily frustrated and had greater difficulty calming themselves when frustrated. Thus, there was an indirect association between co-exposure to tobacco and marijuana and infant behavior via poor growth at delivery."
Furthermore, women who showed symptoms of anger, hostility and aggression reported more stress in pregnancy and were more likely to continue using tobacco and marijuana throughout pregnancy. Therefore, due to the co-exposure, they were more likely to give birth to infants smaller in size and who were more irritable and easily frustrated. The infants' irritability and frustration is also linked to mothers who experienced higher levels of stress while pregnant.
"Our results suggest that interventions with women who smoke cigarettes or use marijuana while pregnant should also focus on reducing stress and helping them cope with negative emotions," Eiden says. "This may help reduce prenatal substance exposure and subsequent behavior problems in infants."
The study appeared in the March/April issue of Child Development and was authored by Pamela Schuetze, PhD, Department of Psychology, Buffalo State College, with co-authors Eiden; Craig R. Colder, PhD, UB Department of Psychology; Marilyn A. Huestis, PhD, Institute of Emerging Health Professions, Thomas Jefferson University, Philadelphia; and Kenneth E. Leonard, PhD, RIA director.
https://www.sciencedaily.com/releases/2018/05/180510145924.htm