Cannabis use in early pregnancy is associated with poor pregnancy outcomes

As more states legalize recreational marijuana, researchers are investigating the potential health effects of cannabis use during pregnancy.

In a new study presented today at the Society for Maternal-Fetal Medicine (SMFM) annual meeting, The Pregnancy Meeting™, and published in American Journal of Obstetrics and Gynecology -; Researchers will unveil results suggesting that cannabis use in the first six to 14 weeks of pregnancy is associated with poor pregnancy outcomes, closely related to placental function.

The placenta plays important roles during pregnancy, including providing an infant with oxygen and nutrients, removing harmful waste and carbon dioxide, and producing hormones that help the baby grow. Medications, drugs, alcohol and nicotine can be transferred from a pregnant person’s bloodstream to her baby through the placenta.

Researchers analyzed urine samples collected during the Nulliparous Mothers-to-Be (nuMoM2b) study, a large, diverse, multicenter cohort of pregnant women. Of the 10,038 nuMoM2b participants, the researchers included data from 9,257 pregnant women in their first trimester of pregnancy.

After drug screening for marijuana, the researchers found that 540 (5.8 percent) tested positive for marijuana, meaning these individuals most likely used cannabis in the first six to 14 weeks of their pregnancy. The study found that cannabis use in early pregnancy is associated with adverse pregnancy outcomes related to the placenta, such as: B. poor growth of the fetus, stillbirth and an increased risk of developing high blood pressure during pregnancy.

“We wanted to look specifically at cannabis use in early pregnancy because that is when the placenta is forming, and much of the information we currently have suggests that cannabis use affects the placenta,” says study lead author Torri D. Metz, MD, MS, board-certified maternal-fetal medicine and associate professor of obstetrics and gynecology at the University of Utah Health in Salt Lake City.

“As recreational marijuana use becomes legal in more states, we need better data as patients are interested in understanding the risk of cannabis use during pregnancy so they can make an informed decision.”

The next step, the researchers say, is to examine continued cannabis use during pregnancy and determine if “the window of exposure” plays a role.