girls to marry young and where they are encouraged to bear children as soon as they are able. for example, in some sub-saharan african countries, early pregnancy is often seen as a blessing because it is proof of the young woman's fertility. countries where teenage marriages are common experience higher levels of teenage pregnancies. in the indian subcontinent, early marriage and pregnancy is more common in traditional rural communities than in cities. many teenagers are not taught about methods of birth control and how to deal with peers who pressure them into having sex before they are ready. many pregnant teenagers do not have any cognition of the central facts of sexuality. economic incentives also influence the decision to have children. in societies where children are set to work at an early age, it is economically attractive to have many children. in societies where adolescent marriage is less common, such as many developed countries, young age at first intercourse and lack of use of contraceptive methods (or their inconsistent and/or incorrect use; the use of a method with a high failure rate is also a problem) may be factors in teen pregnancy. most teenage pregnancies in the developed world appear to be unplanned. many western countries have instituted sex education programs, the main objective of which is to reduce unplanned pregnancies and stis. countries with low levels of teenagers giving birth accept sexual relationships among teenagers and provide comprehensive and balanced information about sexuality. teenage pregnancies are common among romani people because they marry earlier. other family members teen pregnancy and motherhood can influence younger siblings. one study found that the younger sisters of teen mothers were less likely to emphasize the importance of education and employment and more likely to accept human sexual behavior, parenting, and marriage at younger ages. younger brothers, too, were found to be more tolerant of non-marital and early births, in addition to being more susceptible to high-risk behaviors. if the younger sisters of teenage parents babysit the children, they have an increased probability of getting pregnant themselves. once an older daughter has a child, parents often become more accepting as time goes by. a study from norway in 2011 found that the probability of a younger sister having a teenage pregnancy went from 1:5 to 2:5 if the elder sister had a baby as a teenager. sexuality in most countries, most males experience sexual intercourse for the first time before their 20th birthday. males in western developed countries have sex for the first time sooner than in undeveloped and culturally conservative countries such as sub-saharan africa and much of asia. in a 2005 kaiser family foundation study of us teenagers, 29% of teens reported feeling pressure to have sex, 33% of sexually active teens reported "being in a relationship where they felt things were moving too fast sexually", and 24% had "done something sexual they didn’t really want to do". several polls have indicated peer pressure as a factor in encouraging both girls and boys to have sex. the increased sexual activity among adolescents is manifested in increased teenage pregnancies and an increase in sexually transmitted diseases. role of drug and alcohol use inhibition-reducing drugs and alcohol may possibly encourage unintended sexual activity. if so, it is unknown if the drugs themselves directly influence teenagers to engage in riskier behavior, or whether teenagers who engage in drug use are more likely to engage in sex. correlation does not imply causation. the drugs with the strongest evidence linking them to teenage pregnancy are alcohol, cannabis, "ecstasy" and other substituted amphetamines. the drugs with the least evidence to support a link to early pregnancy are opioids, such as heroin, morphine, and oxycodone, of which a well-known effect is the significant reduction of libido – it appears that teenage opioid users have significantly reduced rates of conception compared to their non-using, and alcohol, "ecstasy", cannabis, and amphetamine using peers. early puberty main article: precocious puberty girls who mature early (precocious puberty) are more likely to engage in sexual intercourse at a younger age, which in turn puts them at greater risk of teenage pregnancy. lack of contraception main article: birth control adolescents may lack knowledge of, or access to, conventional methods of preventing pregnancy, as they may be too embarrassed or frightened to seek such information. contraception for teenagers presents a huge challenge for the clinician. in 1998, the government of the uk set a target to halve the under-18 pregnancy rate by 2010. the teenage pregnancy strategy (tps) was established to achieve this. the pregnancy rate in this group, although falling, rose slightly in 2007, to 41.7 per 1,000 women. young women often think of contraception either as 'the pill' or condoms and have little knowledge about other methods. they are heavily influenced by negative, second-hand stories about methods of contraception from their friends and the media. prejudices are extremely difficult to overcome. over concern about side-effects, for example weight gain and acne, often affect choice. missing up to three pills a month is common, and in this age group the figure is likely to be higher. restarting after the pill-free week, having to hide pills, drug interactions and difficulty getting repeat prescriptions can all lead to method failure. in the us, according to the 2002 national survey of family growth, sexually active adolescent women wishing to avoid pregnancy were less likely than older women to use contraceptives (18% of 15–19-year-olds used no contraceptives, versus 10.7% for women aged 15–44). more than 80% of teen pregnancies are unintended. over half of unintended pregnancies were to women not using contraceptives, most of the rest are due to inconsistent or incorrect use. 23% of sexually active young women in a 1996 seventeen magazine poll admitted to having had unprotected sex with a partner who did not use a condom, while 70% of girls in a 1997 parade poll claimed it was embarrassing to buy birth control or request information from a doctor. the national longitudinal study of adolescent health surveyed 1027 students in the us in grades 7–12 in 1995 to compare the use of contraceptives among whites, blacks, and hispanics. the results were that 36.2% of hispanics said they never used contraception during intercourse which is a high rate compared to 23.3% of black teens and 17.0% of white teens who also did not use contraceptives during intercourse. in a 2012 study, over 1,000 females were surveyed to find out factors contributing to not using contraception. of those surveyed, almost half had been involved in unprotected sex within the previous three months. these women gave three main reasons for not using contraceptives: trouble obtaining birth control (the most frequent reason), lack of intention to have sex, and the misconception that they "could not get pregnant". in a study for the guttmacher institute, researchers found that from a comparative perspective, however, teenage pregnancy rates in the us are less nuanced than one might initially assume. "since timing and levels of sexual activity are quite similar across , the high u.s. rates arise primarily because of less, and possibly less-effective, contraceptive use by sexually active teenagers." thus, the cause for the discrepancy between rich nations can be traced largely to contraceptive-based issues. among teens in the uk seeking an abortion, a study found that the rate of contraceptive use was roughly the same for teens as for older women. in other cases, contraception is used, but proves to be inadequate. inexperienced adolescents may use condoms incorrectly, forget to take oral contraceptives, or fail to use the contraceptives they had previously chosen. contraceptive failure rates are higher for teenagers, particularly poor ones, than for older users. long-acting contraceptives such as intrauterine devices, subcutaneous contraceptive implants, and contraceptive injections (such as depo-provera and combined injectable contraceptive), which prevent pregnancy for months or years at a time, are more effective in women who have trouble remembering to take pills or using barrier methods consistently. according to encyclopedia of women's health, published in 2004, there has been an increased effort to provide contraception to adolescents via family planning services and school-based health, such as hiv prevention education. sexual abuse studies from south africa have found that 11–20% of pregnancies in teenagers are a direct result of rape, while about 60% of teenage mothers had unwanted sexual experiences preceding their pregnancy. before age 15, a majority of first-intercourse experiences among females are reported to be non-voluntary; the guttmacher institute found that 60% of girls who had sex before age 15 were coerced by males who on average were six years their senior. one in five teenage fathers admitted to forcing girls to have sex with them. multiple studies have indicated a strong link between early childhood sexual abuse and subsequent teenage pregnancy in industrialized countries. up to 70% of women who gave birth in their teens were molested as young girls; by contrast, 25% of women who did not give birth as teens were molested. in some countries, sexual intercourse between a minor and an adult is not considered consensual under the law because a minor is believed to lack the maturity and competence to make an informed decision to engage in fully consensual sex with an adult. in those countries, sex with a minor is therefore considered statutory rape. in most european countries, by contrast, once an adolescent has reached the age of consent, he or she can legally have sexual relations with adults because it is held that in general (although certain limitations may still apply), reaching the age of consent enables a juvenile to consent to sex with any partner who has also reached that age. therefore, the definition of statutory rape is limited to sex with a person under the minimum age of consent. what constitutes statutory rape ultimately differs by jurisdiction (see age of consent). dating violence studies have indicated that adolescent girls are often in abusive relationships at the time of their conceiving. they have also reported that knowledge of their pregnancy has often intensified violent and controlling behaviors on part of their boyfriends. girls under age 18 are twice as likely to be beaten by their child's father than women over age 18. a uk study found that 70% of women who gave birth in their teens had experienced adolescent domestic violence. similar results have been found in studies in the us. a washington state study found 70% of teenage mothers had been beaten by their boyfriends, 51% had experienced attempts of birth control sabotage within the last year, and 21% experienced school or work sabotage. in a study of 379 pregnant or parenting teens and 95 teenage girls without children, 62% of girls aged 11–15 and 56% of girls aged 16–19 reported experiencing domestic violence at the hands of their partners. moreover, 51% of the girls reported experiencing at least one instance where their boyfriend attempted to sabotage their efforts to use birth control. socioeconomic factors a young poverty-stricken girl clutches her child. frontispiece illustration from street arabs and gutter snipes by george carter needham, boston, 1884. teenage pregnancy has been defined predominantly within the research field and among social agencies as a social problem. poverty is associated with increased rates of teenage pregnancy. economically poor countries such as niger and bangladesh have far more teenage mothers compared with economically rich countries such as switzerland and japan. in the uk, around half of all pregnancies to under 18 are concentrated among the 30% most deprived population, with only 14% occurring among the 30% least deprived. for example, in italy, the teenage birth rate in the well-off central regions is only 3.3 per 1,000, while in the poorer mezzogiorno it is 10.0 per 1,000. similarly, in the us, sociologist mike a. males noted that teenage birth rates closely mapped poverty rates in california: county poverty rate birth rate* marin county 5% 5 tulare county (caucasians) 18% 50 tulare county (hispanics) 40% 100 * per 1,000 women aged 15–19 teen pregnancy cost the us over $9.1 billion in 2004, including $1.9 billion for health care, $2.3 billion for child welfare, $2.1 billion for incarceration, and $2.9 billion in lower tax revenue. there is little evidence to support the common belief that teenage mothers become pregnant to get benefits, welfare, and council housing. most knew little about