Women who use marijuana during pregnancy face an increased risk of pre-term birth and other pregnancy complications, according to the findings of new research.
In a study published last month in the Journal of the American Medical Association (JAMA), Canadian researchers indicate that use of cannabis during pregnancy appears to double the risk of a premature birth when compared to women who do not use it during pregnancy.
Researchers conducted a population-based cohort study including more than 661,000 pregnant women and 9,400 pregnant women who were reported cannabis users. The data covered live births and stillbirths among women ages 15 and older in Ontario, Canada between April 2012 and December 2017.
The rate of preterm birth among reported cannabis users was 12%, compared to 6% in women who did not use marijuana during their pregnancy. Preterm birth is a birth that occurs before the 37th week of pregnancy and increases the risk of complications and health problems in the newborn.
The findings also indicate pregnancy marijuana risks may include having smaller than normal babies and having babies that require treatment in the neonatal intensive care unit (NICU). Infants born to marijuana users also had 5-minute Apgar scores less than 4. The Apgar test is a means of quickly assessing a newborn’s overall health. A normal score for a healthy baby is considered seven to 10.
Women who used marijuana during pregnancy were also more likely to experience placental abruption. This is when the placenta separates from the uterus. This can be harmful to the infant because the placenta supplies oxygen and nutrients to the fetus.
Women who used marijuana during pregnancy also have a 66% higher risk of experiencing heavy bleeding and pregnancy loss, according to the lawsuit.
Marijuana Use Increasing As It Becomes Legal In More States
The use of marijuana during pregnancy has doubled among women in the U.S. between 2002 and 2017. It is now legal to use recreationally in 11 states, and legal for medical use in 33. It is decriminalized in 15 states.
A study conducted last year concluded dispensaries in Colorado often spread misinformation regarding the safety of marijuana use during pregnancy. Many dispensaries informed pregnant women it was safe to use cannabis while pregnant to or to help treat morning sickness despite the evidence indicating it can affect the pregnancy and fetus negatively.
In 2017, roughly 7% of pregnant women reported using the drug in the past month. That number will most likely increase as more states pass legalization laws for recreational and medicinal marijuana use.