Teenage pregnancy is pregnancy in a female under the age of 20. A pregnancy can take place before menarche (the first menstrual period), which signals the possibility of fertility, but usually occurs after menarche. In healthy, well-nourished girls, menarche normally takes place around the ages 12 or 13. Whether the onset of biological fertility will result in a teenage pregnancy depends on a number of personal and societal factors. Teenage pregnancy rates vary between countries because of differences in levels of sexual activity, marriage among teenagers, general sex education provided and access to affordable contraceptive options. Worldwide, teenage pregnancy rates range from 143 per 1000 in some sub-Saharan African countries to 2.9 per 1000 in South Korea.
Pregnant teenagers face many of the same obstetrics issues as women in their 20s and 30s. There are however, additional medical concerns for mothers younger than 15. For mothers between 15 and 19, risks are associated more with socioeconomic factors than with the biological effects of age. However, research has shown that the risk of low birth weight is connected to the biological age itself, as it was observed in teen births even after controlling for other risk factor.
In developed countries, teenage pregnancies are associated with many social issues, including lower educational levels, higher rates of poverty, and other poorer life outcomes in children of teenage mothers. Teenage pregnancy in developed countries is usually outside of marriage, and carries a social stigma in many communities and cultures. Many studies and campaigns have attempted to uncover the causes and limit the numbers of teenage pregnancies. Among OECD developed countries, the United States, United Kingdom and New Zealand have the highest level of teenage pregnancy, while Japan and South Korea have the lowest in 2001. The latest data from the United States shows that the states with the highest teenage birthrate are Mississippi, New Mexico and Arkansas while the states with the lowest teenage birthrate are New Hampshire, Massachusetts and Vermont.
Of those teenage girls who choose to continue their pregnancy, a large proportion are from a disadvantaged or dysfunctional socio-economic background. They are increasingly young and, in many cases, were themselves born to teenage mothers (Charbonneau et al. 1989, in Cardinal Remete 1999; Morazin 1991). They generally occupy underpaid and undervalued work positions (Charbonneau et al. 1989, in Cardinal Remete 1999). These young women can nevertheless be very good mothers if they receive proper support.
In some cases, the father of the child is the husband of the teenage girl. The conception may occur within wedlock, or the pregnancy itself may precipitate the marriage (the so-called shotgun wedding). In countries such as India the majority of teenage births occur within marriage.
In other countries, such as the United States and the Republic of Ireland, the majority of teenage mothers are not married to the fathers of their children. In the UK, half of all teenagers with children are lone parents, 40% are cohabitating as a couple and 10% are married. Teenage parents are frequently in a romantic relationship at the time of birth, but many adolescent fathers do not stay with the mother and this often disrupts their relationship with the child. Research has shown that when teenage fathers are included in decision-making during pregnancy and birth, they are more likely to report increased involvement with their children in later years. In the U.S, eight out of ten teenage fathers do not marry their first child's mother.
However, "teenage father" may be a misnomer in many cases. Studies by the Population Reference Bureau and the National Center for Health Statistics found that about two-thirds of births to teenage girls in the United States are fathered by adult men age 20 or older. The Guttmacher Institute reports that over 40% of mothers aged 15–17 had sexual partners three to five years older and almost one in five had partners six or more years older. A 1990 study of births to California teens reported that the younger the mother, the greater the age gap with her male partner. In the UK 72% of jointly registered births to women under the age of 20, the father is over the age of 20, with almost 1 in 4 being over 25