Real risks associated with cannabis exposure during pregnancy
January 17, 2020
Science Daily/University of Western Ontario
A new study from researchers at Western University and Queen's University definitively shows that regular exposure to THC, the main psychoactive ingredient in cannabis, during pregnancy has significant impact on placental and fetal development. With more than a year since the legalization of recreational cannabis in Canada, the effects of its use during pregnancy are only now beginning to be understood.
The study, published today in Scientific Reports, uses a rat model and human placental cells to show that maternal exposure to THC during pregnancy has a measurable impact on both the development of the organs of the fetus and the gene expression that is essential to placental function.
The researchers demonstrated in a rat model that regular exposure to a low-dose of THC that mimics daily use of cannabis during pregnancy led to a reduction in birth weight of 8 per cent and decreased brain and liver growth by more than 20 per cent.
"This data supports clinical studies that suggest cannabis use during pregnancy it is associated with low birth weight babies. Clinical data is complicated because it is confounded by other factors such as socioeconomic status," said Dan Hardy, PhD, Associate Professor at Western's Schulich School of Medicine & Dentistry and co-author on the paper. "This is the first study to definitively support the fact that THC alone has a direct impact on placental and fetal growth."
The research team was also able to characterize how THC prevents oxygen and nutrients from crossing the placenta into the developing fetus. By studying human placental cells, the researchers found that exposure to THC caused a decrease in a glucose transporter called GLUT-1. This indicates that the THC is preventing the placental transfer of glucose, a key nutrient, from the mother to the fetus. They also found a reduction in placental vasculature in the rat model suggesting reduced blood flow from the mother to the fetus.
The researchers say both of those factors are likely contributing to the growth restriction that they observed in the offspring.
The researchers point out that there are currently no clear guidelines from Health Canada on the use of cannabis in pregnancy and some studies have shown that up to one in five women are using cannabis during pregnancy to prevent morning sickness, for anxiety or for social reasons.
"Marjiuana has been legalized in Canada and in many states in the US, however, its use during pregnancy has not been well studied up until this point. This study is important to support clinicians in communicating the very real risks associated with cannabis use during pregnancy," said David Natale, PhD, Associate Professor at Queen's and co-author on the paper.
https://www.sciencedaily.com/releases/2020/01/200117104756.htm
Iron supplements have long-term benefits for low birth-weight babies
Follow-up study finds early iron intervention can lower levels of aggression and rule-breaking behavior in children age 7
September 27, 2017
Science Daily/Springer
Babies classified as low birth weight (under 2,500 grams) are at risk of iron deficiency, which is linked to impaired neurological development. A long-term randomized study now shows that providing such babies with iron supplements can prevent behavioral problems at school age.
The findings are part of ongoing Swedish research involving 285 late preterm and term infants who weighed between 2000 grams and 2500 grams at birth, and were defined as being marginally low birth weight. This group represents a significant number of all births. The babies were randomly selected to receive either no iron supplements, or specific doses from the age of six weeks to six months.
Research up until now has shown that those babies given iron supplements had a lower risk of suffering from iron deficiency or iron deficiency anemia by the time they were six months old. When the participants were tested again when they were 3 and a half years old, the ones in the supplement group had fewer behavioral problems than those who went without extra iron.
In this study, 207 of the participants from the initial investigation were tested at the age of seven. Berglund and his fellow researchers wanted to see if the early iron intervention influenced the children's cognitive and neurobehavioral abilities. The Wechsler Intelligence Scale for Children was used to assess the children's cognitive abilities. Their parents completed two standardized questionnaires about their children's behavior.
No major differences were found in the intelligence scores of the children in the two separate test groups. The magnitude of the intervention group to show externalizing problems was however significantly reduced compared to that of the children in the other. They had lower levels of aggressive and rule-breaking behavior, and did not suffer as many thought problems. The thought problems in question were recently shown to be the best independent predictor of autism spectrum disorders. This suggests that the behavioural and emotional profiles of low birth weight children who did not receive iron supplements include different symptoms of subclinical neurodevelopmental problems.
"Our findings suggest that iron supplementation may have long-lasting effects on behavioural functions in children born of a low birth weight," says Berglund. "This clinically important benefit from early iron supplementation gives further support to recommend iron supplementation of all low birth weight children, including those with marginally low birth weight."
On the population level this finding is important, since marginally low birth weight infants represent a relatively large proportion of all births. Up to five percent of infants born in high income countries and fifteen percent of those in low income countries are defined as such.
https://www.sciencedaily.com/releases/2017/09/170927123600.htm