Teenage pregnancy, also known as adolescent pregnancy, is pregnancy in females under the age of 20.A female can become pregnant from sexual intercourse after she has begun to ovulate, which can be before her first menstrual period (menarche) but usually occurs after the onset of her periods. In well-nourished females, menarche usually takes place around the age of 12 or 13.

Pregnant teenagers face many of the same pregnancy related issues as other women. There are, however, additional concerns for those under the age of 15 as they are less likely to be physically developed enough to sustain a healthy pregnancy or to give birth.For girls aged 15–19, risks are associated more with socioeconomic factors than with the biological effects of age. Risks of low birth weight, premature labor, anemia, and pre-eclampsia are connected to the biological age, being observed in teen births even after controlling for other risk factors (such as accessing prenatal care etc.).

In developed countries, teenage pregnancies are associated with social issues, including lower educational levels, poverty, and other negative 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. By contrast, teenage parents in developing countries are often married, and their pregnancies welcomed by family and society. However, in these societies, early pregnancy may combine with malnutrition and poor health care to cause medical problems.

When used in combination, educational interventions and promotion of birth control can reduce the risk of unintended teenage pregnancies.In developing countries, 7.3 million females under age 18 give birth per year.If all pregnancies are included, the number of adolescent pregnancies is much higher.

According to the United Nations Population Fund (UNFPA), "Pregnancies among girls less than 18 years of age have irreparable consequences. It violates the rights of girls, with life-threatening consequences in terms of sexual and reproductive health, and poses high development costs for communities, particularly in perpetuating the cycle of poverty."Health consequences include not yet being physically ready for pregnancy and childbirth leading to complications and malnutrition as the majority of adolescents tend to come from lower-income households. The risk of maternal death for girls under age 15 in low and middle income countries is higher than for women in their twenties.Twenties pregnancy also affects girls' education and income potential as many are forced to drop out of school which ultimately threatens future opportunities and economic prospects.

Several studies have examined the socioeconomic, medical, and psychological impact of pregnancy and parenthood in teens. Life outcomes for teenage mothers and their children vary; other factors, such as poverty or social support, may be more important than the age of the mother at the birth. Many solutions to counteract the more negative findings have been proposed. Teenage parents who can rely on family and community support, social services and child-care support are more likely to continue their education and get higher paying jobs as they progress with their education.

A holistic approach is required in order to address teenage pregnancy. This means not focusing on changing the behaviour of girls but addressing the underlying reasons of adolescent pregnancy such as poverty, gender inequality, social pressures and coercion. This approach should include "providing age-appropriate comprehensive sexuality education for all young people, investing in girls' education, preventing child marriage, sexual violence and coercion, building gender-equitable societies by empowering girls and engaging men and boys and ensuring adolescents' access to sexual and reproductive health information as well as services that welcome them and facilitate their choices."

In the United States one third of high school students reported being sexually active. In 2011–2013 79% of females reported using birth control. Teenage pregnancy puts young women at risk for health issues, economic, social and financial issues.

Being a young mother in a first world country can affect one's education. Teen mothers are more likely to drop out of high school.However, recent studies have found that many of these mothers had already dropped out of school before becoming pregnant, but those in school at the time of their pregnancy were as likely to graduate as their peers. One study in 2001 found that women who gave birth during their teens completed secondary-level schooling10–12% as often and pursued post-secondary education 14–29% as often as women who waited until age 30.Young motherhood in an industrialized country can affect employment and social class. Less than one third of teenage mothers receive any form of child support, vastly increasing the likelihood of turning to the government for assistance.The correlation between earlier childbearing and failure to complete high school reduces career opportunities for many young women. One study found that, in 1988, 60% of teenage mothers were impoverished at the time of giving birth.Additional research found that nearly 50% of all adolescent mothers sought social assistancewithin the first five years of their child's life.[18] A study of 100 teenaged mothers in the United Kingdom found that only 11% received a salary, while the remaining 89% were unemployed.Most British teenage mothers live in poverty, with nearly half in the bottom fifth of the income distribution.Teenage women who are pregnant or mothers are seven times more likely to commit suicide than other teenagers.Professor John Ermisch at the institute of social and economic research at Essex University and Dr Roger Ingham, director of the centre of sexual health at Southampton University – found that comparing teenage mothers with other girls with similarly deprived social-economic profiles, bad school experiences and low educational aspirations, the difference in their respective life chances was negligible.

Teenage motherhood may actually make economic sense for young women with less money, some research suggests. For instance, long-term studies by Duke University economist V. Joseph Hotz and colleagues, published in 2005, found that by age 35, former teen mothers had earned more in income, paid more in taxes, were substantially less likely to live in poverty and collected less in public assistance than similarly poor women who waited until their 20s to have babies. Women who became mothers in their teens—freed from child-raising duties by their late 20s and early 30s to pursue employment while poorer women who waited to become mothers were still stuck at home watching their young children—wound up paying more in taxes than they had collected in welfare.Eight years earlier, the federally commissioned report "Kids Having Kids" also contained a similar finding, though it was buried: "Adolescent childbearers fare slightly better than later-childbearing counterparts in terms of their overall economic welfare."

According to the National Campaign to Prevent Teen Pregnancy, nearly 1 in 4 teen mothers will experience another pregnancy within two years of having their first.Pregnancy and giving birth significantly increases the chance that these mothers will become high school dropouts and as many as half have to go on welfare. Many teen parents do not have the intellectual or emotional maturity that is needed to provide for another life.[citation needed] Often, these pregnancies are hidden for months resulting in a lack of adequate prenatal care and dangerous outcomes for the babies. Factors that determine which mothers are more likely to have a closely spaced repeat birth include marriage and education: the likelihood decreases with the level of education of the young woman – or her parents – and increases if she gets married.

Prevention:

Comprehensive sex education and access to birth control appear to reduce unplanned teenage pregnancy.It is unclear which type of intervention is most effective.

In the United States free access to a long acting form of reversible birth controlalong with education decreased the rates of teen pregnancies by around 80% and the rate of abortions by more than 75%.Currently there are four federal programs aimed at preventing teenage pregnancy: Teen Pregnancy Prevention (TPP), Personal Responsibility Education Program (PREP), Title V Sexual Risk Avoidance Education, and Sexual Risk Avoidance Education.

The Dutch approach to preventing teenage pregnancy has often been seen as a model by other countries. The curriculum focuses on values, attitudes, communication and negotiation skills, as well as biological aspects of reproduction. The media has encouraged open dialogue and the health-care system guarantees confidentiality and a non-judgmental approach.

Some schools provide abstinence-only sex education. Evidence does not support the effectiveness of abstinence-only sex education. It has been found to be ineffective in decreasing HIV risk in the developed world,and does not decrease rates of unplanned pregnancy when compared to comprehensive sex education. It does not decrease the sexual activity rates of students, when compared to students who undertake comprehensive sexual education classes.Some schools provide abstinence-only sex education. Evidence does not support the effectiveness of abstinence-only sex education.[98] It has been found to be ineffective in decreasing HIV risk in the developed world,[99] and does not decrease rates of unplanned pregnancy when compared to comprehensive sex education.[98] It does not decrease the sexual activity rates of students, when compared to students who undertake comprehensive sexual education classes.