They admit that "researchers don't know a lot about what the effects might be" and "the research is in progress", but say "most experts advise pregnant women not to use marijuana", in part because "many of the chemicals in marijuana (in particular, tetrahydrocannabinol or THC) can pass through a mother's system to her baby and can negatively affect a baby's health". In 2016, almost a quarter of pregnant teenagers had used marijuana, as had about one in five women between 18 and 24.
About 21.8% of pregnant teens (people under 18) reportedly used marijuana in 2016, compared to 12.5% in 2009.
The American Academy of Pediatrics and the American Congress of Obstetricians and Gynecologists discourage the use of marijuana during pregnancy due to its connections to other developmental issues.
Some soon-to-be-moms are turning to marijuana to quell the uncomfortable side effects of pregnancy such as morning sickness.
The researchers noted marijuana was the "most commonly used illegal drug during pregnancy", and could "impair fetal growth and neuro-development", Reuters reported.
Trump prolongs feud with FBI's McCabe over Clinton ties
GOP congressman Peter King speaks out on the alleged political bias of FBI Deputy Director Andrew McCabe . Seven minutes later, Trump dredged up an old ( and debunked ) attack on McCabe's wife for a tweet .
Worryingly, if women are not reporting their marijuana use in their medical records, their doctors are unable to counsel them about the risks of using marijuana, or what alternative reliefs for symptoms like nausea might be available.
Overall, there was an increase in cannabis use among study subjects, from four percent to seven percent, over the seven-year period. The study adds that prenatal use may increase even more in 2018, after recreational use of marijuana is set to become legal in California. However, self-reported data is notoriously unreliable.
More than half of all Americans reported having tried marijuana at some point in their lives, and about 22 percent of those qualify as regular users. Urine tests, which are more reliable, also have their limitations; marijuana can linger in a person's urine about 30 days-and even longer for those just light up more than every once in a while.
Young-Wolff said marijuana usage increased the most in young females. A total of 23 states have laws that allow the use of marijuana for medicinal purposes to some extent. "We recommend (pregnant women) stop immediately".