A new study finds marijuana use before or during early pregnancy increases the risk of serious, potentially life-threatening complications in pregnant individuals, CNN reports.

Researchers at Kaiser Permanente found pregnant individuals who used marijuana during early pregnancy had a 17% greater risk of gestational hypertension and 8% greater risk of preeclampsia compared with those who did not use marijuana. Both are potentially serious disorders related to high blood pressure during pregnancy. People who used marijuana in early pregnancy also had a 19% greater risk of placental abruption, where the placenta suddenly detaches from the side of the uterus. It can cause bleeding, pain and complications for the fetus and the birthing parent.

“Research suggests that pregnant people are bombarded with inaccurate messages from social media, cannabis retailers and peers suggesting that cannabis use during pregnancy is safe,” said lead researcher Kelly Young-Wolff. “Our study provides timely and important data that adds to the growing body of evidence indicating that cannabis use during pregnancy is not safe.”