Moms-to-be exposed to cannabis are 50 percent more likely to suffer pregnancy complications, warns new research.
The study involving more than 9,000 expectant American women found that cannabis exposure during pregnancy was associated with a range of negative health issues – especially low birth weight.
Higher exposure was associated with higher risks – and it is best to avoid the drug altogether while pregnant, say scientists.
The research team said the study, published by the Journal of the American Medical Association (JAMA), was larger and measured cannabis exposure more accurately than previous research, allowing them to distinguish the effects of the drug itself from those caused by other health issues.
Professor Robert Silver, of the University of Utah Health, said: “Cannabis use is not safe.
“It increases the risk of pregnancy complications. If possible, you shouldn’t use cannabis during pregnancy.”
Study lead author Dr. Torri Metz, also of the University of Utah Health, said: “There’s so much information out there – discussion and social media channels and on the internet – about cannabis use and pregnancy.
“I think it’s hard for patients to understand what they should be worried about, if anything.”
Some previous studies on the subject found no association between cannabis use and pregnancy complications.
Dr. Metz said one hurdle facing such research is that there are “so many differences between baseline characteristics of people who use and don’t use cannabis during pregnancy.”
She added: “There’s different rates of anxiety and depression.
”These differences can also impact pregnancy risks, which makes it challenging to figure out the consequences related specifically to cannabis use.”
The researchers said 610 of the participants had detectable levels of cannabis exposure.
The scientists found that cannabis exposure was associated with a 1.5-fold increase in risk.
Just over one in four (26 percent) of the moms-to-be exposed to cannabis experienced an unhealthy outcome, compared to 17 percent of those who weren’t.
Higher levels of cannabis exposure over the course of pregnancy were associated with higher risks, according to the findings.
While previous studies had asked participants to report their own cannabis use – which has been shown to underestimate the actual rate of use, the research team measured the levels of a metabolic by-product of cannabis in urine samples, which gave more accurate measurements.
To gauge impacts on pregnancy, the researchers looked at an aggregate measure of negative health outcomes, including low birth weight, pregnancy-related high blood pressure, stillbirth, and medically indicated preterm birth.
The association between cannabis use and low birth weight was found to be the strongest.
The researchers said that all of the conditions have been linked to reduced function of the placenta, which supplies the growing baby with oxygen and nutrients.
Previous studies in non-human primates have found that long-term cannabis exposure can interfere with blood supply to the placenta.
The correlation Dr. Metz and her colleagues observed suggests that cannabis may disrupt the human placenta in a similar way.
Silver says that the greater risk seen at higher levels of exposure is “especially concerning” given the high amount of THC found in newer cannabis products – products that were barely starting to become available from 2010 to 2014, when the study data was collected.
The researchers urged women considering using cannabis while pregnant to have an open conversation with their doctor.
They said that while moms-to-be may turn to cannabis to alleviate nausea or anxiety, other remedies have been proven to be safe.
Silver said: “There are many, many reasons people use cannabis.
“But there may be alternative therapies that can help mitigate the symptoms.”
He added: “As long as humans are interested in using this product, we ought to assess health effects both good and bad, as accurately as we can, and provide that information for folks.”
Produced in association with SWNS Talker
