Less favorable socioeconomic situations, such as a teen's family's poor education and income levels, may lead to high adolescent birth rates. Teenagers in child welfare systems are more likely than other groups to have a teen pregnancy or give birth. They are also more likely to continue having children at a young age. The number of adolescents who become pregnant is increasing. The majority of these pregnancies are unplanned; many adolescents are not using contraception. Because adolescents' reproductive organs aren't fully developed, they are at risk for medical complications during childbirth. Children born to mothers under the age of 18 are more likely to be premature or low birth weight. Both maternal and infant mortality increase if the mother is under the age of 17. Teens who are sexually active are more likely to be exposed to HIV/AIDS. Although adults too are affected by this virus, it is primarily adolescents who are becoming infected with HIV. The main reason behind this trend is that adults are aware of the risks involved with sexual activity and are taking measures to prevent infection. Adolescents on the other hand are not taking these risks seriously which makes them vulnerable to HIV/AIDS. The number of adolescents giving birth is also increasing. More teens are choosing cosmetic surgery over childbirth. Teens are going into debt to pay doctors to cut off their breasts for implants or remove fat from other areas of their bodies.