CHICAGO (AP) - Pot
use in pregnancy has doubled among U.S. women and is most common during the
first trimester, government research shows.
Overall, 7% of
pregnant women, or 1 in 14, said they used marijuana in the past month.
That’s from a nationally representative health survey in 2016-17 and
compares with a little over 3% in 2002-03.
Some studies have
linked marijuana use during pregnancy with increased chances of premature
birth and low birthweight. Animal studies have linked high doses early in
pregnancy with fetal brain abnormalities, but whether typical use in humans
poses similar risks is unknown, said Dr. Nora Volkow, director of the
National Institute on Drug Abuse.
"Because we don’t
know exactly how harmful it is, it’s better to err on the side of caution,”
said Volkow, one of the authors of the government study. Marijuana use
during pregnancy “is not worth the risk,” she said Tuesday.
The study was
presented at a medical meeting Tuesday and published online in the Journal
of the American Medical Association.
First trimester use
jumped from almost 6% to 12%. Many women may have used pot before they
learned they were pregnant, or used it to ease morning sickness, although
few women said a doctor had recommended it, Volkow said.
Among women who
weren’t pregnant, the rate of marijuana use increased from almost 7% to
nearly 12%, or 1 in 8.
The results are
based on health surveys involving nearly half a million U.S. women who were
questioned during a period when rising numbers of states legalized marijuana
for medical or recreational use. It’s legal in 10 states for both uses but
remains illegal federally.
A separate study on
marijuana use among pregnant Canadian women, published in the same journal,
adds to evidence suggesting that pot use in pregnancy may lead to premature
birth. A journal editorial notes that like similar previous studies, the
Canadian research can’t rule out whether other factors that may have
warned against relying on imperfect data to make judgments about potential
harms from marijuana use and said more rigorous research is needed. Volkow
said U.S. government restrictions on marijuana research are “very much an
issue” and have hampered efforts to answer fundamental questions about pot