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  • Using cannabis during pregnancy is linked to having children with higher levels of stress and anxiety, according to a new study.
  • There’s an established link between maternal cannabis use and neuro-developmental issues, such as attention deficit hyperactivity disorder (ADHD), in children.
  • Many unknowns about maternal cannabis use persist, and doctors continue to advise against cannabis use during pregnancy due to the potential harms to the fetus.

Cannabis use during pregnancy may be linked to children with levels of anxiety, stress, and hyperactivity, according to a study published in the Proceedings of the National Academy of Science Monday.

Researchers from the Icahn School of Medicine at Mount Sinai and the City University of New York sampled pregnant women’s placentas. The researchers found changes in immune system genes, which may explain why the children had greater anxiety later in life.

There’s an established link between maternal cannabis use and neuro-developmental issues, such as attention deficit hyperactivity disorder (ADHD), in children.

Although there are many unknowns about the impact cannabis has on the developing fetus, doctors continue to advise against maternal cannabis use due to the potential short-term and long-term harms.

“It surely contributes to our growing knowledge of the risks associated with cannabis use during pregnancy, and further supports the take-home message to women that, at present, our understanding leads us to recommend not using cannabis during pregnancy and breastfeeding,” said Dr. Jordan Tishler, an instructor of medicine at Harvard Medical School and the president of the Association of Cannabinoid Specialists.

The research team studied placental gene expression and early childhood behaviors in 322 mother-child pairs.

When the children were 6 years old, the researchers measured the children’s heart function via electrocardiogram recordings and hormone levels via hair samples.

The children’s behavioral and emotional functioning was also evaluated via surveys.

The research team found that kids whose mothers used cannabis during their pregnancy had higher levels of anxiety, aggression, hyperactivity, and stress.

These children also had abnormalities in their heart rate, which have been associated with greater stress sensitivity.

Sampling of the placenta revealed that maternal cannabis use was linked to irregularities with immunity-related genes, which could explain why their children had greater anxiety, according to the researchers.

According to Dr. Scott Krakower, a child and adolescent psychiatrist at Zucker Hillside Hospital in Glen Oaks, New York, maternal cannabis use has previously been linked to worsening disorders and neurodevelopment issues, like ADHD, in children later in life.

“This study reinforced it… and they used hormones and placentas to show that there were changes in the overall immune cascade, which could lead to worsening anxiety and hyperactivity,” Krakower said.

Cannabis is one of the most common drugs used during pregnancy, and maternal cannabis use has been on the rise given the increased legalization.

The American College of Obstetricians and Gynecologists estimates cannabis use during pregnancy ranges between 2 and 5 percent. That estimate increases to 15 to 28 percent among young, urban, socially disadvantaged women.

Many people believe it’s safer to use cannabis than smoke tobacco during pregnancy. But animal models have shown that the active chemicals in cannabis can cross the placenta.

Though scientists are still learning about the link between cannabis use during pregnancy and its impact on fetal development, findings suggest that fetal exposure to cannabinoids can negatively affect brain development.

Previous studies have linked maternal cannabis use to decreased attention span and behavioral problems in the children.

Cannabis products are not tightly regulated, so it’s hard to know the exact potency of what someone is ingesting, which could be dangerous to both the child and mother.

There have been reports of cannabis leading to psychosis and worsening psychotic symptoms and mood symptoms.

“If the mother is doing well, then the baby is going to do well. But if the mother’s mental health is not doing great or there’s ingestion of other substances and stuff, the outcome of the baby may not be as good as you want it to be,” Krakower said.

Krakower says there’s a strong correlation between anxiety and cannabis use. However, it’s unclear why cannabis users have more anxiety.

“That is either because, A, you’re more anxious and you’re more likely to use marijuana, or B, using marijuana is possibly worsening the anxiety over the long run,” Krakower said.

If the mother has anxiety in the first place, there’s a chance they could pass it on to their children as well.

“Would the kid have had anxiety anyway? I’m not sure,” said Krakower but pointed out that but it seems likely there may be a change in “neuroendocrine access.”

There may be other factors contributing to the children’s mental health, which the study did not account for.

“There is also no accounting for life events between pregnancy and the beginning of the study — such as trauma or even simply being raised in a household where parental, guardian, sibling anxiety is part of daily life,” Tishler said.

More studies following mothers and their children from conception to adulthood are needed to better understand the short-term and long-term impacts of maternal cannabis use.

New research suggests maternal cannabis use is associated with higher levels of anxiety, stress, and hyperactivity in children later in life.

Researchers suspect this is because cannabis can trigger changes in genes involved with immune functioning, contributing to anxiety.

Though many unknowns about maternal marijuana use persist, doctors continue to advise against cannabis use during pregnancy due to the potential harms to the fetus.