A study published in the journal Addictive Behaviors reports that 59 percent of pregnant teens have used one or more illicit substances in the last 12 months. This is two times more than non pregnant teens.

The study was based off a sample that included almost 100,000 adolescent and teenage girls age 12-17. About 800 of the teens were pregnant. During their pregnancies, alcohol was the most commonly used substance, coming in at 16 percent. This was followed by cannabis, 14 percent,  and other illicit drugs, five percent. Although the pregnant teens’ drug use was high during the first trimester, it dramatically decreased during the second and third trimesters of pregnancy.

Drinking or doing drugs during pregnancy is not only harmful for these teens, but also for their babies. Specifically, alcohol during pregnancy can cause birth defects, miscarriages and stillborns. This study did not report on the health of the babies.

The study also showed that the girls who had parental support were less likely to use substances than those who do not. This further proves there should be open communication between parents and children about drugs and drug abuse.