Teenagers who get pregnant are unusually likely to use drugs or alcohol prior to pregnancy, and substance-using teens also have heightened chances of continuing drug or alcohol intake during pregnancy, according to new findings from a group of American researchers. In the U.S., teen pregnancy is associated with a range of negative outcomes for both mothers and their children. In a study published in February 2015 in the journal Addictive Behaviors, researchers from three U.S. universities examined the connection between teen substance use, teen substance problems and the odds of getting pregnant during adolescence. These researchers also assessed the odds that a teenager will keep using drugs or alcohol while pregnant.\r\nTeen Pregnancy\r\nThe federal Centers for Disease Control and Prevention track the number of teenagers between the ages of 15 and 19 who become pregnant and give birth in any given year. In the last year with fully available statistics (2012), 29.4 out of every 1,000 girls and young women in this age range gave birth to at least one child. These numbers reflect the lowest rate of teen pregnancy since the CDC started tracking this area of public health. Between 2011 and 2012, teen pregnancy and birth rates fell by a significant amount among both younger teens in the target group (those individuals age 15, 16 or 17) and older teens (those individuals age 18 or 19). Potential explanations for the historic low in teen pregnancy and birth rates include increasingly widespread use of effective birth control and a generally reduced rate of teen involvement in sexual activity. There are a number of serious problems associated with giving birth as a teenager. Examples of these problems include heightened chances that any teenage girl will fail to finish high school and heightened chances that a child born to a teenage mother will develop an unusually large number of health issues, fail to finish high school, also get pregnant while still in adolescence or get arrested before reaching adulthood. Crucially, these damaging outcomes still occur even when other relevant factors (including income level, educational level, academic performance and residence in a single-parent household) are taken into account.\r\nTeens and Substance Use\/Abuse\r\nThe highest rates of teen substance use\/abuse typically occur among older teenagers, while the lowest rates typically occur among younger teenagers. The National Institute on Drug Abuse and the University of Michigan use a project called Monitoring the Future to track substance intake rates in three grades of younger and older teens: eighth graders, 10th graders and 12th graders. In 2014, the most widely used substances among both younger and older adolescents (eighth graders and 12th graders) were alcohol and marijuana\/cannabis. Other substances used\/abused with considerable frequency in both age groups included synthetic marijuana, the ADHD medication Adderall, tranquilizers and dextromethorphan-containing cough syrup. Eighth graders also had a relatively high level of involvement in inhalant use.\r\nTeen Pregnancy, Substance Use and Substance Problems\r\nIn the study published in Addictive Behaviors, researchers from the University of Texas at Austin, St. Louis University and the University of Michigan used 10 years of data from a nationwide project called the National Survey on Drug Use and Health to explore the connection between substance use in adolescence, substance problems in adolescence and the odds of experiencing a teen pregnancy. All told, the collected data included information from 97,850 preteen and teenage girls between the ages of 12 and 17; 810 of these individuals became pregnant. For the preteens and teens affected by pregnancy, as well as for the preteens and teens who did not get pregnant, the researchers assessed the frequency of a history of substance use or serious substance problems (diagnosable abuse or addiction) in the previous month and in the previous year. The researchers ultimately concluded that, at the time of pregnancy, affected teen and preteen girls are unusually likely to have a history of substance use, as well as a history of diagnosable problems related to marijuana\/cannabis consumption, alcohol consumption or the intake of some other substance. They also concluded that, compared to their adult counterparts, currently pregnant teenage girls are unusually likely to continue substance intake during their pregnancies. As a rule, pregnant preteens and young teens up to the age of 14 have substantially greater chances of continuing substance use in pregnancy than their older counterparts between the ages of 15 and 17.