Julie Fennell. Encyclopedia of the Life Course and Human Development. Editor: Deborah Carr. Volume 2. Macmillan Reference USA, 2009.

In its broadest scientific scope, birth control may be defined as any attempt to limit the number or control the spacing of births. In this sense, birth control includes a wide variety of modern contraceptive technologies and traditional non-technological contraceptive methods, male and female sterilization, as well as the postconception birth control methods of abortion and infanticide. Modern contraceptives generally refer to technological methods, from condoms to birth control pills; traditional contraceptives generally refer to nontechnological methods, particularly withdrawal (ejaculation outside the vagina) and the rhythm method (which tries to determine women’s fertile periods and avoid intercourse during those times). Although the role of postconception methods of birth control remains significant in both developed and developing nations, this entry will focus solely on birth control methods designed to prevent conception (i.e., contraception).

It should be noted that in common American parlance, birth control often connotes “the pill,” whereas contraception connotes condoms or contraceptive technologies. Although the distinction between modern and traditional methods remains important in the study of birth control, the most important distinction in the study of contraceptive technologies is between barrier and hormonal or intrauterine methods of contraception. Barrier methods include condoms, diaphragms, and spermicidal agents and attempt to create a physical barrier between the sperm and the egg to prevent conception. They are coitus dependent, meaning that they are only used during and near coitus (i.e., sexual intercourse), and they are characterized by moderately high efficacy levels in the prevention of pregnancy, although male and female condoms offer extremely effective prevention against sexually transmitted infections (STIs).

Hormonal and intrauterine methods of contraception include oral contraceptive pills (OCPs) and intrauterine devices (IUDs) and are methods that attempt to suppress the release of eggs or create an inhospitable uterine environment for an embryo’s development. These methods are used independently of coitus, meaning that they are used essentially at all times, and they are characterized by extremely high efficacy levels in the prevention of pregnancy but offer no protection against STIs. As fertility rates around the world have plummeted, contraception has become a normal part of adolescents’ and adults’ lives in many countries; meanwhile, fears about the spread of HIV have made condom use a major public health concern.

Trends in Birth Control Use Across Time

Attempts at birth control have been made since ancient times. Such attempts included lambskin condoms and tortoiseshell diaphragms. By far the most successful of these premodern methods was withdrawal, which was an approved Islamic practice for centuries (Santow, 1995). Demographers believe that the first stage of the demographic transition in Europe, the period when birth rates declined sharply, was accomplished primarily through the use of withdrawal. By the late 1800s early versions of condoms and diaphragms had been invented, but the historical accounts suggest that the early formulations of these methods were awkward and that their use was not widespread because of physical discomfort and strong social stigma; the more contemporary versions of these contraceptives were not used until the 1930s.

The modern contraceptive era really began in the early 1960s with the introduction of the OCP, followed several years later by the development of the copper IUD. OCPs, IUDs, condoms, and diaphragms remained the primary methods of contraception from the 1960s to the 1980s. However, since the early 1990s, there has been a proliferation of birth control methods, including new OCP and IUD formulations, as well as hormonal birth control delivery through a patch, a ring, shots, and implants. Emergency contraception (popularly known as “the morning after pill”) also emerged in the late 1990s as a method that women could take up to 78 hours after unprotected sex to prevent pregnancy.

Male hormonal methods have been in development for years, but at this writing, none are currently available on the market. Since the 1980s the HIV and AIDS crisis around the world has increased the desirability of condoms as a method of protection and prompted the development of a variety of improved condoms. Among these new condoms are female condoms, which are condoms that are inserted into the vagina and intended to provide a female-controlled method of STI prevention. Unfortunately, their successful use requires male cooperation, which may reduce their usefulness for women. Male condoms remain the standard method of STI prevention. Because male and female condoms possess the dual capacity to prevent pregnancy and STIs, encouraging the use of condoms has become a major public health priority. In order to promote a greater variety of methods of both disease and pregnancy prevention, researchers have been pursuing the development of female-controlled vaginal microbicidal agents, which seek to kill sperm to prevent conception and disease; unfortunately, initial trials have not been promising in effectiveness and women’s willingness to use them.

Access to OCPs and IUDs varied greatly among nations for decades, with many predominantly Catholic countries, such as Spain and Italy, not legalizing them until the late 1970s. The last highly developed country to legalize OCPs was Japan, which did so in 1999. However, dates of legalization often do not correspond directly with dates of widespread access. The United States, for instance, legalized OCPs in 1961 but continued to restrict unmarried women’s access to them until 1972 when a Supreme Court ruling assured access. Although widespread use of hormonal or intrauterine methods is often still very limited in many developing countries, most new birth control methods—including the first OCPs—were first tested in developing countries.

As of the early 21st century, the most popular method of birth control worldwide is female sterilization, followed by the IUD, although there is significant variation by country. In the United States, for example, the most popular form of birth control is female sterilization, followed closely by OCPs; the pattern is similar in Latin America. Asia, dominated by the contraceptive patterns of China, shows a strong preference for female sterilization and IUDs but not OCPs. Although contraceptive use is uncommon in much of Africa, preference patterns there resemble those in Europe; on both continents, female sterilization is rare, and the favored methods are OCPs and IUDs.

Hormonal or intrauterine methods of birth control are distinguished by their extremely high rates of effectiveness in preventing pregnancy, their independence from coitus, their feminine control, and their medical supervision. In developed countries, where these methods are widely used, the combination of these factors has resulted in women experiencing an increase in control over their reproductive health, while producing a simultaneous increase in medical surveillance over women’s bodies. OCPs are generally considered essential in propelling the sexual revolution in developed countries during the 1960s and 1970s and disconnecting sexual desire from pregnancy and childbearing, which had traditionally been closely linked, particularly through the institution of marriage. Prior to the post-World War II (1939-1945) baby boom, family size had been steadily declining, and the decline continued after the introduction of hormonal and intrauterine methods. Scholars generally agree that these contraceptive methods played a significant role in this family size decline but disagree about how large that role really was.

Although the role of hormonal and intrauterine methods in creating smaller families is debatable, the widespread use of these methods undoubtedly helped to create the expectation that the timing and number of births could be easily controlled. This expectation, in turn, allowed women to enter the labor market seeking not merely jobs but careers—that is, jobs that required extensive education and training and that assume a trajectory through promotions. In the early 21st century, many European countries are facing average fertility levels that are well below replacement levels (that is, below 2.1 births per woman), a situation that would probably be impossible without the widespread use of hormonal and intrauterine birth control.

The effect of hormonal and intrauterine birth control methods has been slower to reach many developing countries, where demand for smaller families is often lower and where medical institutions are often poorly equipped to meet existing demands. Scholars continue to debate the extent to which economic development and urbanization drive the demand for smaller families and birth control versus the extent to which smaller families and birth control permit greater development and urbanization. China continues to be the most famous case study for examining this question. Through the imposition of a system of major governmental rewards and penalties, China successfully created a massive demand for contraception (particularly the IUD) and overhauled normative values about family size. The centerpiece of China’s population policy is its one-child policy, which penalizes most couples for having more than one child. Although China’s population control program would probably not have been possible without hormonal and intrauterine contraceptive technologies, most demographers agree that the existence of birth control cannot in and of itself create a demand for smaller family sizes. Rather, the individual, economic, social, or cultural pressures for family planning must first be in place before birth control is likely to be used. Yet birth control is not always used to create smaller families. Researchers in Africa have documented many cases in which modern birth control methods are desired as a means to accomplish careful birth spacing, which in turn is viewed as a means to attain larger, not smaller, family sizes.

Birth Control Usage and Effectiveness

Evaluating the efficacy of birth control methods in preventing pregnancy (and to a lesser extent, in curbing disease transmission) is one of the major goals in the study of birth control. Clinical studies produce perfect use estimates by rigorously monitoring the use of a birth control method according to its instructions and calculating the probability of becoming pregnant while using the method in the first year. Perfect use statistics for most hormonal and intrauterine methods are typically around 99.9%, meaning that in the first year of use, 1 out of every 1,000 women will become pregnant if she uses the method according to directions. Given the millions of women using these methods, however, thousands may become pregnant every year despite these unlikely sounding odds. Perfect use statistics for barrier methods vary widely but are generally around 90%, meaning that in the first year of use, 10 out of every 100 women using them will become pregnant. For short-term methods such as OCPs and barrier methods, the probability of becoming pregnant declines in subsequent years of use (i.e., women are less likely to become pregnant in the second than the first year of use), but for long-acting methods such as IUDs and contraceptive implants, pregnancy is more likely to occur in later years of use.

Perfect use statistics are contrasted with typical use statistics, which are derived from surveys conducted with contracepting women about the actual likelihood of becoming pregnant while using a particular method. These statistics typically make use of questions asking women whether or not they were using a particular method in the month that they conceived and thus may include condom users who only used condoms once among many acts of intercourse during a month. Not surprisingly, typical use efficacy estimates are often much lower than perfect use estimates, with OCP effectiveness down to about 93% (7 in 100 women becoming pregnant) and condom effectiveness down to between 80 and 85% (20 to 15 in 100 women becoming pregnant) in the first year of use. Some researchers argue that the user error—for example, women forgetting to take their pills—should not be considered in evaluating contraceptive effectiveness, but others argue that considering the effectiveness of contraception without clinical assistance is essential to evaluating its real protective capacity.

In keeping with this line of reasoning, it should be noted that the difference between the perfect use and typical use rates of many long-acting methods of birth control, particularly the IUD and birth control implants, is almost nonexistent, meaning that they generally achieve their theoretical effectiveness level in normal use. Birth control researchers are also attentive to socio-economic differences in method choice (that is, what groups prefer which methods and why) and failure rates, with statistics often indicating that underprivileged women are less likely to use contraceptive methods consistently and more likely to experience contraceptive failures even when they do use them, although the mechanisms behind this trend are not well-understood.

One of the major goals of birth control researchers has been to identify women who say they do not want children in the near future but who are not using a method of birth control; in aggregate, this is referred to as unmet need. Numerous criticisms have been leveled against the traditional conceptualization of unmet need, particularly its focus on hormonal and intrauterine methods of contraception. Critics point out that many of these women have valid reasons for not using modern methods of birth control and that portraying these women as traditional or primitive for failing to use appropriate methods ignores the many legitimate objections that women have for avoiding these methods. These objections include the many uncomfortable side effects that arise from hormonal and intrauterine birth control, such as disrupted menstrual cycles and moodiness, diminished pleasure from condoms, and financial expense. Feminist critics have also argued that fertility researchers’ almost exclusive emphasis on hormonal and intrauterine methods ignores the problematic implications of widespread medical surveillance of women’s bodies and vastly underestimates the health consequences of extended hormonal and intrauterine method use. Researchers have responded to these criticisms in ways that have reshaped the study of birth control.

First, rather than focusing exclusively on women’s unmet need, researchers have moved toward a greater focus on the contraceptive needs of women and men, often specifically looking at couples. Whereas earlier research was frequently accused of portraying men as obstacles to women’s contraceptive access, recent research has begun to look more broadly at the way that women and men facilitate and deter each other’s contraceptive use. Second, in response to the criticism that unmet need did not adequately address the relationship between fertility desires, contraceptive desires, and contraceptive use, researchers have begun to explore the relationship between pregnancy intentionality and birth control use in more depth. Pregnancy intentionality refers to women’s, men’s, and couple’s desires and intentions for more children. Research has emphasized the often uncertain nature of pregnancy intentionality, conflicts between partners, and the effects of these patterns on contraceptive use. Both of these changes to contraceptive research have been strongly informed by the contributions from qualitative research (interviews, focus groups, and ethnographies), both in developed and developing countries. Although the study of contraception continues to be dominated by quantitative research based on surveys, mixed-method studies combining qualitative and quantitative data, as well as qualitative studies on their own, have proliferated in this field. Qualitative contributions have demonstrated the role of social networks in spreading contraceptive use, as well as illustrating some of the social and cultural obstacles people encounter in trying to negotiate contraceptive use with significant others.

Despite these developments, research on birth control use around the world continues to focus disproportionately on adolescents. Critics argue that this focus both reflects and contributes to the problematic aspects of adolescent sexuality, but proponents argue that contraceptive habits formed in adolescence will probably continue into young adulthood. In the U.S. context, at least, the emphasis on adolescent contraceptive use seems perhaps unwarranted because unintended pregnancies are actually most likely to occur to women between ages 18 and 24. Research focusing specifically on adults’ contraceptive use has been so lacking that one of the key journals in the field, Perspectives on Sexual and Reproductive Health, plans a special issue on the subject. The paucity of research in this area raises many questions about birth control use across the life course, particularly in the face of major fertility-related events, such as abortion, childbirth, marriage, and divorce. Scholars do not know, for example, how women and men decide that they are finished with childbearing, even though they regularly refer to completed fertility. Researchers also know that rates of male and female sterilization differ considerably among nations yet know very little about why this is.

Another issue that has been neglected in the study of birth control is the way that considerations of pleasure influence contraceptive use, decision making, and negotiation. Researchers have posited many different reasons why condom use in every society is so much lower than public health officials would like, often emphasizing women’s lack of control over male condom use. However, few researchers have addressed the fact that both men and women in many different cultures feel that condoms seriously diminish their sexual pleasure, which may be the most salient reason for not using them. The limited attention the issue has received has almost always been directed toward reductions in men’s sexual pleasure, typically ignoring women’s lost sexual pleasure from condoms as well as their reduced libido from many hormonal methods.

Policy Issues

Birth control continues to be the subject of religious, policy, and political controversy. The Catholic church still officially condemns all methods of birth control other than the natural family planning method it developed based on the rhythm method; yet there is little evidence that most Catholics obey this religious tenet. Other religious groups, such as the Mormons, strongly promote the value of large families while still approving of birth control. National policies likewise range from active government promotion of birth control in China and Iran to government discouragement of population limitation in some African countries.

In general, developing countries frequently struggle with issues of access to, availability of, and acceptability of contraception. One of the greatest obstacles for developing countries is establishing a medical infrastructure capable of managing women’s reproductive health care needs, from the safe implantation of IUDs to the timely distribution of OCPs. Normative societal mandates also may prevent unmarried women from obtaining contraceptives, especially in cultures where husbands must approve of their wives’ use of contraceptives. Furthermore, distrust of foreign doctors and medicine often make many people in developing countries wary of unfamiliar contraceptive methods. Contraceptive concerns vary widely by region, with some African countries, such as Botswana (where one in three people may be infected with HIV), facing an HIV epidemic that makes condom use seem essential but other methods of birth control superfluous. Meanwhile, many Asian countries, particularly India and China, have made population control a major social priority and have been successful at distributing contraceptives to large swaths of their populations.

Birth control controversy in developed countries also focuses around access but more specifically the issues of adolescents’ access and medical intervention. Some countries allow adolescents unfettered access to contraception, whereas others require parental permission for them to obtain it. Even when it is ostensibly available to them, adolescents may have difficulty obtaining contraceptives because of financial, transportation, or confidentiality issues. In many countries, hormonal contraceptives are available without a doctor’s prescription (over-the-counter), whereas others, such as the United States, restrict access through medical providers. The United States recently made emergency contraception available to people over 18 over-the-counter, but the issue was clouded in controversy, especially because many view emergency contraception as an abortion-inducing intervention. Political controversy also continues about the extent to which young people should receive formal education about the use of contraception. Research, however, overwhelmingly demonstrates that education about contraceptive methods does not make adolescents more likely to have sex but does make them more likely to use protection when they do. For both adolescents and adults, birth control use is essential in assuring family limitation and the prevention of STIs, and the study of birth control provides insights into the most efficient and user-friendly means to accomplish these ends.