Volume 6, Chapter 1. The Importance of Contraception

Chapter 1
The Importance of Contraception
Andrew M. Kaunitz
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Andrew M. Kaunitz, MD
Professor and Assistant Chair, Department of Obstetrics and Gynecology, University of Florida Health Science Center, Jacksonville, Florida (Vol 2, Chap 71; Vol 6, Chas 1, 15, 28)

BENEFITS OF EFFECTIVE CONTRACEPTION
MAJOR EVENTS IN BIRTH CONTROL IN THE UNITED STATES
CURRENT CONTRACEPTIVE USE AND UNINTENDED PREGNANCIES IN THE UNITED STATES
COMPARISON OF CONTRACEPTIVE EFFICACY, COSTS, AND BENEFITS
EMERGING CONTRACEPTIVES
CONCLUSIONS
REFERENCES

BENEFITS OF EFFECTIVE CONTRACEPTION

With the chapters in this volume that address specific contraceptive methods and issues, this introductory chapter provides an overview of the overall benefits of birth control, details contraceptive practices (particularly among US women), and concludes by comparing the efficacy, costs, and benefits of existing as well as emerging reversible contraceptives.

By reducing unintended pregnancies and abortions, and facilitating family planning/spacing of births, effective contraception provides both health and social benefits to mothers and their children. According to worldwide estimates, some 600,000 women die each year of pregnancy-related causes, and 75,000 die following unsafe abortions.¹ At least 200,000 of these maternal deaths are attributable to the failure or lack of contraceptive services.² In addition to preventing mortality, effective contraception improves maternal health. Data from the well-controlled Intergenerational Panel Study of Mothers and Children, a 31-year longitudinal survey of 1113 mother-child pairs, indicate that unwanted births can lead to nonpsychotic major depression (postpartum depression), feelings of powerlessness, increased time pressures, and a reduction in overall physical health.³ Finally, effective contraception improves the social and economic role of women and enables them to participate in society fully.⁴^,⁵

Infants and children also derive benefits from effective contraception. As modern contraceptive methods have become more widely available throughout the world, infant mortality has decreased from approximately 150 deaths per 1000 live births in the 1950s to 80 deaths per 1000 live births in the 1990s.⁴ In developing countries, 53% of married women plan family size, and 90% of them use modern birth control methods such as female sterilization, oral contraceptives (OCs), and intrauterine devices (IUDs).⁴ According to Population Action International, infant mortality in developing countries could be decreased by one third by increasing the spacing between births to 2 to 4 years.¹ The health status of infants and children is also improved as the result of effective contraception. In the 31-year mother-child survey, unwanted children had more health problems, such as lower birth weight and higher mortality, than those who had been wanted.³ Mothers who had an unwanted birth also had a poorer quality relationship with all their children, tending to spank them more and spend less leisure time with them.³ In addition, evidence indicates that children from large families generally receive less education.¹

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MAJOR EVENTS IN BIRTH CONTROL IN THE UNITED STATES

Key events in the availability of modern contraceptive in the United States are summarized in Table 1.⁴^,⁶ Although many refer to these events as the contraceptive revolution, Diczfalusy recently observed that “many scientists wonder whether or not contraception is still a revolution or rather a normal way of life—with significantly improved quality of life-for a billion couples.”⁷ Condoms have been available for hundreds of years, yet most major advances in contraception have occurred since the 1960s and 1970s.⁶ OCs and IUDs were introduced in the early 1960s, and both had become highly popular methods of contraception by the 1970s, as use of the diaphragm and male condom waned.⁶^,⁸ However, the 1980s saw a dramatic decrease in IUD use as the result of concerns about intrauterine infections.⁴^,⁸ Today, only 0.8% of US women use IUDs compared with nearly 100 million women worldwide.⁶ Major changes occurred during the 1990s as condom use among adolescents increased, probably because of public health efforts to increase awareness about the risks of human immunodeficiency virus infection and other sexually transmitted diseases (STDs), and OC use decreased slightly.⁴^,⁹ Additionally, approval of levonorgestrel implants and the depot medroxyprogesterone acetate (DMPA) contraceptive injection provided methods that offered excellent protection in less user-dependent forms.⁶ In fact, the decline in teen pregnancies seen in the last decade has been attributed largely to increased use of DMPA.¹⁰
TABLE 1. Key Events in Availability of Modern Contraceptive Methods in the United States

Year
Event

1925
First manufacture of diaphragms in United States

1937
American Medical Association endorses birth control

1942
Planned Parenthood Federation of America established

1960
Birth control pill approved by Food and Drug Administration (FDA)

1960
Intrauterine device approved by FDA

1970
Family Planning Services and Population Research Act creates Title X of Public Health Service Act

1972
Medicaid funding for family planning services authorized

1983
Contraceptive sponge approved for sale in the United States

1990
Public service announcements for condoms appear on national television for the first time

1990
Norplant approved by FDA

1992
Depo-Provera approved by FDA

1993
Reality female condom (vaginal pouch) approved by FDA

1995
Contraceptive sponge withdrawn from market by manufacturer; condom use reaches new high levels

1997
Emergency use of oral contraceptive pills approved by FDA

2000
Lunelle monthly injection and Mirena IUD approved by FDA
(Adapted from Centers for Disease Control and Prevention. Achievements in public health 1900---1998, Family planning. MMWR Morb Mortal Wkly Rep 48:1073---1080, 1999 and Speroff L: A quarter century of contraception: Remarkable advances, increasing success. Contemp Ob/Gyn May 15:13---14, 19---20, 27---28, 1998.)

CURRENT CONTRACEPTIVE USE AND UNINTENDED PREGNANCIES IN THE UNITED STATES

The 1995 National Survey of Family Growth (NSFG) provides the most current definitive data on the contraceptive methods used by US women aged 15 to 44 years. As shown in Figure 1, female and male sterilization and OCs account for 65% of contraceptive usage.⁹ DMPA, levonorgestrel (Norplant), and IUDs account for another 5% of contraceptive use. Therefore, 30% of US women are not using effective contraceptive methods.

Fig. 1. Percentage distribution of contraceptive users (aged 15 to 44) by current method.(Adapted from Piccinino LJ, Mosher WD: Trends in contraceptive use in the United States: 1982–1995. Fam Plann Perspect 30:4–10, 1998.)

In both Canada and the United States, a substantial percentage of those desiring contraception rely on male or female sterilization, whereas in France, only 3% of women use female sterilization and male sterilization is virtually nonexistent (Table 2).⁹^,¹¹^,¹² The percentage of US women who rely on the male condom as their contraceptive method is twice that in either Canada or France. Fewer than 30% of US women and fewer than 20% of Canadian women use OCs as their contraceptive method. France is unique among these developed countries, with its fairly high level of OC use, even among older women, and of IUD use, and its low use of female sterilization. Access to female sterilization is limited in France and in many developing nations.¹² In less developed countries, the IUD is the most popular modern reversible contraceptive method, followed by the male condom.² However, in more developed regions, the OC is the most popular method of birth control, followed by the male condom and then by the IUD.²

TABLE 2. Comparison of Contraceptive Methods Used in Developed Countries: 1994---1994

Country	Ages	Method (Percentage of Reproductive-Age Women Using)
		OC	IUD	Male Condom	Male/Female Sterilization
United States	15---44	26.9	0.8	20.4	38.6 (female 27.7)
Canada	15---49	16.9	2.6	9.5	27.9 (female 17.3)
France	20---44	40.2	15.8	7.8	3.0 (female only)

(Adapted from Piccinino LJ, Mosler WD: Trends in contraceptive use in the United States: 1982---1995. Fam Plan Perspect 30:10, 41, 1998; Martin K, Wu Z: Contraceptive use in Canada: 1984---1995. Fam Plan Perspect 32:65---73, 2000; and Touleman L, Leridon H: Contraceptive practices and trends in France. Fam Plan Perspect 30:114---120, 1998.)

Despite the many advances made in contraception, access to a wide range of method choices is limited, even in developed countries. When nations were ranked according to the availability of six contraceptive methods (male sterilization, female sterilization, OCs, IUDs, injectables, and condoms) in 1996, the United States ranked sixth as a result of low availability of the IUD (Fig. 2).¹

Fig. 2. Contraceptive access in selected developed nations, 1996.(How Family Planning Protects the Health of Women and Children. Washington, DC: Population Action International, 1997.)

Likewise, Italy and France ranked tenth and eleventh because of limited access to sterilization, and Japan ranked last because at that time OCs were not available. Lack of an adequate variety of contraceptive choices has a direct impact on the percentage of couples who use any method. Data from 36 developing countries indicate that when only one or two methods are available, the prevalence of contraceptive use is lower than 30%, whereas when five or six methods are available, use increases to more than 60%.²

High Rates of Sterilization in US Women

In the United States, couples have compensated for the lack of contraceptive choices by increased reliance on voluntary sterilization.¹³ According to estimates for women from the 1995 NSFG and for men from the 1987–1988 National Survey of Family Households (NSFH), three quarters of all intact marriages rely on sterilization as the contraceptive method.¹⁴ Based on data from the National Hospital Discharge Survey for the period from 1970 to 1995, Westhoff and Davis estimate that 11 million US women aged 15 to 44 years rely on tubal sterilization for contraception.¹⁵ Each year in the United States, 700,000 sterilization procedures are performed; half these are done as outpatient procedures.¹⁵

Those who opt for surgical sterilization to prevent pregnancy believe that the method is “foolproof” when, in fact, failure rates across all types of procedures have been underestimated at 0% to 0.4%.¹⁶ The US Collaborative Review of Sterilization (CREST), a multicenter, prospective cohort study that included a total of 10,685 women who underwent tubal sterilization between 1978 and 1986 at 16 US medical centers, found 10-year cumulative rates ranging from 7.5 to 1000 for unipolar coagulation and postpartum partial salpingectomy to 36.5 to 1000 with spring clip application¹⁷ (Table 3). The risk of pregnancy was highest among women who were sterilized at younger ages (28 to 33 years) compared with those sterilized at age 34 years and older.

TABLE 3. Life-Table Cumulative Probabilities of Pregnancy Among Women Undergoing Tubal Sterilization by Method (Cumulative Probability per 1000 Procedures and 95% Confidence Interval)

Method (n)*	Years Since Sterilization
	1	5	10
Bipolar coagulation (2267)	2.3 (0.3---4.2)	16.5 (10.6---22.4)	24.8 (16.2---33.3)
Unipolar coagulation (1432)	0.7 (0.0---2.1)	2.3 (0.0---4.8)	7.5 (1.1---13.9)
Silicone rubber band (3329)	5.9 (3.3---8.5)	10.0 (6.4---13.5)	17.7 (10.1---25.3)
Spring clip (1595)	18.2 (11.5---24.9)	31.7 (22.6---40.7)	36.5 (25.3---47.7)
Interval partial salpingectomy (425)	7.3 (0.0---15.5)	15.1 (3.1---27.1)	20.1 (4.7---35.6)
Postpartum partial salpingectomy (1637)	0.6 (0.0---1.9)	6.3 (2.2---10.3)	7.5 (2.7---12.3)
All methods (10,685)	5.5 (4.1---6.9)	13.1 (10.8---15.4)	18.5 (15.1---21.8)

n, number of women sterilized.
(Adapted from Peterson, HB et al: The risk of pregnancy after tubal sterilization: Findings from the U.S. Collaborative Review of Sterilization. Am J Obstet Gynecol 174:1161---1170, 1996.)

Several factors contribute to the high prevalence of sterilization among US couples. Coverage of costs by health care providers has a major impact on contraceptive choice. A recent survey by the Alan Guttmacher Institute found that 85% to 90% of all managed care plans routinely covered tubal sterilization and vasectomy and at least two thirds covered abortions performed by dilatation and curettage or suction aspiration (Fig. 3).¹⁸

Fig. 3. Surgical sterilization and abortion procedures are covered by the majority of all types of managed care plans.(Survey of Private-Sector Insurance Coverage of Reproductive Health Services. New York: Alan Guttmacher Institute, 1993.)

This is in sharp contrast to the coverage provided for reversible contraception by these same health care plans (Fig. 4).¹⁸

Fig. 4. Reversible contraceptive coverage varies widely by method and type of plan.(Survey of Private-Sector Insurance Coverage of Reproductive Health Services. New York: Alan Guttmacher Institute, 1993.)

None of the reversible contraceptive methods is routinely covered by 49% of typical indemnity plans, and only 15% cover provider costs for all five of the most commonly used methods: IUD, diaphragm, contraceptive implant, injection, and OC. Moreover, although most traditional indemnity plans and preferred provider organizations provide coverage for prescription drugs in general, only about 40% routinely cover the cost of OCs.¹⁸ In contrast, coverage for OCs is provided by 84% of health maintenance organizations.

The attention given by the news media to negative reports regarding reversible methods of contraception has also contributed to high use of female sterilization in the United States. According to Philip D. Darney in a conversation in April 2000:

The heavy reliance of American couples on sterilization rather than temporary methods is due partly to reimbursement issues and partly to the negative reputation one method after another has acquired as a result of scare stories by the media—beginning with the birth control pill scare in the early 1970s, the Dalkon Shield debacle in the late 1970s, and then the Norplant reaction in the 1990s. Couples have been literally driven toward sterilization. The final irony is evidence showing that sterilization isn't necessarily more effective than the IUD or Norplant or even oral contraceptives.

Education also affects contraceptive practices. Data from the 1995 NSFG showed that among non-Hispanic white and non-Hispanic black women aged 22 to 44, use of female sterilization decreased as the woman's years of education increased.⁹ Among those with less than 11 years of schooling, 50% used female sterilization and 11% used male sterilization. By contrast, among those with at least 13 years' education, 16% used female sterilization and 14% used male sterilization as the contraceptive method. Combined data from the 1995 NSFG and the 1987–1988 NSFH indicate that among couples who chose sterilization, the likelihood of female sterilization relative to vasectomy decreases as the wife's education increases, which is consistent with the expectation that better-educated husbands are more likely to undergo vasectomy.¹⁴

Frank provides further insight into the impact that education can have in improving use of reversible contraceptive methods.¹⁹ A comparison of data on contraceptive use from the 1993–1994 Women Physicians' Health Study, which included female physicians aged 30 to 44 and the general population of women aged 15 to 44 (1990 NSFG) showed that overall, female physicians were more likely to use contraception than higher income nonphysicians (73% versus 64%).

As shown in Figure 5, compared with the general population of higher income women, female physicians were five times more likely to use IUDs (5% versus 1%), more likely to use diaphragms (18% versus 4%) and condoms (20% versus 17%), and less likely to use tubal sterilization (12% versus 25%) or vasectomy (10% versus 16%). Compared with other female physicians, obstetrician/gynecologists were more likely to use OCs, diaphragms, and IUDs and less likely to rely on male or female sterilization. However, Frank notes that the comparisons may have been biased by the lower fecundity and higher rates of marriage of these female physicians. Sterilization is not an appropriate contraceptive method until careful consideration has been given to irrevocably ending childbearing potential.

Fig. 5. Use of different contraceptive methods by women physicians and higher income women in the general population.(Adapted from Frank E: Contraceptive use by female physicians in the United States. Obstet Gynecol 94:666–671, 1999.)

Unintended Pregnancy and Abortion

Nearly half of all pregnancies and one third of all births in the United States in 1994 were unintended, and over 50% of unintended pregnancies ended in abortion (Table 4).²⁰

TABLE 4. Unintended Pregnancy by Age Group: United States, 1994

	Age at Outcome (yr)
	15---19	20---24	25---29	30---34	35---39	40	Total
Pregnancies unintended (%)	78.0	58.5	39.7	33.1	40.8	50.7	49.2
Births unintended (%)	66.0	38.7	22.2	18.0	23.2	26.7	30.8
Unintended pregnancies ended in abortion (%)	45.3	55.2	56.7	55.7	56.3	64.7	54.0

Numerator for rates includes women aged 40 and older; denominator includes women aged 40---44.
(Adapted from Henshaw SK: Unintended pregnancy in the United States. Fam Plan. Perspect 30:24---29 & 46, 1998.)

The highest rates of unintended pregnancies and births occurred in teens (ages 15 to 19) and young women (ages 20 to 24), followed by older reproductive-age women at least 40 years of age (Fig. 6). However, compared with 1987, the rate of unintended pregnancies in 15- to 19-year-olds declined from 79.3 in 1000 women to 71.1 to 1000 women.²¹ This decline is attributable primarily to increased use of long-acting hormonal contraception by teenagers.⁴^,⁹

Fig. 6. Rate of unplanned births in developed countries.(Adapted from Alan Guttmacher Institute: Sharing Responsibility: Women, Society and Abortion Worldwide, p 17. New York: Alan Guttmacher Institute, 1999.)

The rate of unintended births in the United States is similar to those in Canada, which has comparable contraceptive access, and higher than that in Sweden where a greater number and variety of contraceptive methods are available (see Fig. 2).¹^,⁴^,²¹^,²² However, the abortion rate in the United States is higher than that of other developed countries as well as many less-developed nations (Fig. 7).²¹^,²² For example, according to recent statistics, the abortion rate per 1000 women aged 14 to 44 years was 6.5 in the Netherlands and 20 to 22.9 in the United States.²³ With its heavy reliance on abortion and sterilization to limit family size, the United States resembles a less developed country more than it does other industrialized nations, such as Germany or Canada.

Fig. 7. Abortion rates by country.(Adapted from Sharing Responsibility: Women, Society and Abortion Worldwide, p 17. New York: Alan Guttmacher Institute, 1999.)

COMPARISON OF CONTRACEPTIVE EFFICACY, COSTS, AND BENEFITS

As shown in Figure 8, contraceptive methods with high first-year failure rates during typical use are periodic abstinence, withdrawal, male condoms, diaphragms, and spermicides.²⁴^,²⁵ Highly effective methods with low first-year failure rates during typical use include copper or progesterone-bearing IUDs, OCs, implants, injectables, and sterilization.

Fig. 8. Contraceptive failure during first year of use.(Data from Burnhill MSA: Contraceptive use: the U.S. perspective. Int J Gynecol Obstet 62(Suppl 1):S17–S23, 1998; and Hatcher RA, Trussell J, Stewart F et al: Contraceptive Technology. 17th rev ed. New York: Ardent Media, 1998.)

The results of a recent 60-week, US multicenter, controlled, nonrandomized, parallel study in which 1103 women used either a monthly contraceptive injection containing MPA and estradiol cypionate (E₂) (Lunelle, n = 782) or an OC-containing triphasic norethindrone (NET) and ethinyl estradiol (Ortho-Novum 7/7/7, n = 321) demonstrate the high effectiveness that can be achieved with reversible contraceptives.²⁶ In this trial, one unintended pregnancy was reported at the third visit in a patient receiving the OC and no pregnancies occurred during 13 cycles of 28 days in study subjects receiving monthly injections. Pregnancy rate estimates using Pearl index and life-table methods were 0.0 and 0.0, respectively, with the monthly injection and 0.3 and 0.4, respectively, with the OC. Thus, both the monthly injections and the OC provided a high degree of contraceptive efficacy. Because this was a clinical trial, participants were highly motivated (and monitored). Accordingly, higher failure rates are observed in routine clinical practice. Increased use of these and other highly effective methods of contraception by US women would decrease rates of unintended pregnancy and induced abortion.

Effective methods of contraception are also highly cost-effective (Fig. 9).²⁷ In an analysis in the managed care payment model, 5-year costs associated with reversible methods increase as the effectiveness of the method decreases; nearly all cost with less effective methods is related to unintended pregnancy rather than method acquisition.²⁷ With the highest cost-effective reversible methods—copper-T IUD, implants, and injectables—method acquisition accounts for most of the cost. Costs of barrier methods are increased by unintended pregnancy. Among permanent methods of contraception, female sterilization is less cost effective than vasectomy as the result of the greater cost of tubal sterilization, including operating room and anesthesia requirements.

Fig. 9. The 5-year costs associated with contraceptive methods in the managed care payment model.(Adapted from Trussell J, Leveque JA, Koenig JD et al: The economic value of contraception: A comparison of 15 methods. Am J Public Health 85:494–503, 1995.)

Characteristics of highly effective, reversible contraceptive methods are compared in Table 5. Several comments are warranted with regard to differences in benefits and risks associated with these methods. In terms of major risks, OCs are known to have procoagulant effects related to the estrogen component. Such procoagulant changes increase users' risk of deep vein thrombosis. Although procoagulant effects were most pronounced with high estrogen-dose OC formulations, mild procoagulant effects within the normal range have been reported with formulations containing 35 μg or less of estrogen.¹³ Unlike OCs, DMPA does not increase globulin production in the liver and is not associated with increases in procoagulant factors.²⁸ No procoagulant changes are seen with either levonorgestrel implants or the copper IUD.²⁸

TABLE 5. Comparison of Highly Effective, Reversible Contraceptive Methods

Parameter	OC	DMPA	Implants	Copper Ultrauterine Device
Efficacy	User dependent	High	High	High
Length of protection	Continuous if taken daily	3 months	5 years	10 years
Rapid return of fertility	Yes	No	Yes	Yes
Regular cycles	Yes	No	Variable	Yes
Amenorrhea	Uncommon	Common	Variable	No
Appropriate in nursing mothers	Suboptimal	Yes	Yes	Yes
Procoagulant	Yes	No	No	No
Noncontraceptive benefits	Established	Established	Unknown	No
Provider required to initiate	Yes (Rx)	Yes	Yes	Yes
Provider required to discontinue	No	No	Yes	Yes
Privacy	Requires pill pack	Yes	Seen or felt by some users	Usually (string may be felt by partner)

OC, oral contraceptives; DMPA, depot medroxyprogesterone acetate.
(Adapted from Kaunitz AM: Injectable contraception: New and existing options. Obstet Gynecol Clin North Am 27:741---780, 2000.)

Another concern with hormonal methods of contraception is their impact on bone mineral density (BMD). Several studies of OCs, DMPA, and levonorgestrel implants have examined changes in BMD. A history of OC use was found to be protective against low BMD in a US cross-sectional study.²⁹ In a large Swedish case-control study, OC use by women age 40 and older was associated with a 25% reduction in postmenopausal hip fracture risk.³⁰ Studies have found the OC use has a protective effect against osteopenia in young, reproductive-age women with hypoestrogenic conditions (e.g., hypothalamic amenorrhea or anorexia nervosa), and helps maintain BMD in older reproductive-age women with declining ovarian function.³¹ Available data suggest that use of levonorgestrel implants may have a neutral or beneficial effect on BMD.³²

The impact of current or past use of DMPA on BMD has been the addressed by 13 studies.²⁸ Overall, current use of DMPA appears to be associated with a decrease in BMD that is reversible following cessation of use and therefore unlikely to have clinical importance. A New Zealand study found that postmenopausal bone mineral density in former DMPA users was not significantly different from that of never-users at any site.³³ In this regard, the impact of DMPA on bone density resembles that of lactation in that both lower ovarian production of estradiol, leading to reversible declines in BMD.²⁸

In contrast to implants and the copper IUD, both OCs and DMPA have many well-established noncontraceptive benefits. Both OCs and DMPA prevent iron-deficiency anemia, ectopic pregnancy, pelvic inflammatory disease, and endometrial cancer.³⁴^,³⁵ Additional noncontraceptive benefits of OCs include protection from dysmenorrhea and menorrhagia, ovarian cysts, benign breast disease, and ovarian cancers, emerging benefits such as the treatment of acne and dysfunctional uterine bleeding, and the prevention of osteopenia and osteoporotic fractures.³⁰^,³⁴^,³⁶ An additional noncontraceptive benefit of DMPA is a reduced need for hysterectomy in women with uterine leiomyomata.³⁵

Protection against STDs represents a critical issue for reproductive-age women. Because the trend toward initiating sexual activity at a younger age and postponing marriage until an older age places women at increased risk for both unintended pregnancy and STDs, clinicians should try to encourage use of contraceptive options that achieve both goals. However, as shown in Table 6, the most effective reversible contraceptive methods (DMPA, implants, IUDs and OCs) do not protect users against STDs, whereas a method with relatively low contraceptive efficacy—the male condom—provides the greatest STD protection.³⁷

TABLE 6. Protection Against Sexually Transmitted Diseases (STDs) with Different Contraceptive Methods

Contraceptive Method	Effects on Bacterial STDs	Effects on Viral STDs
Diaphragm, cervical cap, sponge	Some protection against cervical infection; increases organisms associated with bacterial vaginosis	No protection against vaginal infection or external genitalia transmission; prevention of HPV controversial
Female condom	In vivo protection against recurrent trichomonal infection suggests possible protection against other STDs	In vitro impermeability to cytomegalovirus, HIV
IUD	No protection	No protection
Latex male condom	Protection against most pathogens in genital fluids	Less protection against organisms such as HSV and HPV transmitted from external genitalia
Combination oral contraceptive	No protection against bacterial STDs	Data on HIV transmission risks conflicting; role regarding risk of HPV infection and cervical dysplasia unclear
DMPA implants	Assume no protection	May promote HIV transmission
Spermicide with nonoxynol-9	Modest protection against cervical gonorrhea and chlamydia	Data conflicting on HIV transmission risks
Tubal ligation	No protection	No protection

HPV, human papillomavirus; HIV, human immune deficiency virus; IUD, intrauterine device. HSV, herpes simplex virus; DMPA, depot medroxyprogesterone acetate.
(Adapted from Cates W Jr, Sulak PJ: Contraceptives and STDs: Alternative approaches to providing dual protection. Dialog Contracept 6:1---4, 9, 2000.)

Providing the dual benefits of protection against pregnancy and STDs is a particularly vexing challenge among adolescents. Clinicians have noted that long-acting hormonal preparations such as DMPA or levonorgestrel represent better options than OCs for pregnancy prevention in this age-group because they remove need for daily compliance.³⁸ However, a recent study in urban teens found that those using levonorgestrel were less likely to report condom use at last sexual contact or consistent condom use at follow-up 1 or 2 years later than users of OCs or condoms.³⁹ These findings suggest that both the sexual behavior and motivation to use condoms in teens who use implants differ from those of teens who use OCs and condoms. In addition, teens often fail to use OCs or condoms in a fashion sufficiently consistent to prevent either unintended pregnancy or STDs.

EMERGING CONTRACEPTIVES

Contraceptive methods that may be available in the United States in the near future are described in Table 7. These include a monthly injection containing medroxyprogesterone acetate/estradiol cypionate (MPA/E₂C, Lunelle, a two-rod levonorgestrel subdermal implant (Norplant-II), a one-rod etonorgestrel implant (Implanon), an IUD that releases levonorgestrel 20 μg/day for up to 7 years (LNG-20 IUD, Mirena), a vaginal ring that releases etonorgestrel and ethinyl estradiol (NuvaRing) and is discarded after 3 weeks to allow menses, and a 1-week transdermal patch that releases 17-desacetylnorgestimate and ethinyl estradiol (EVRA). A US company has also announced its intentions to reintroduce the Today contraceptive sponge impregnated with 1-g nonoxynol-9. Data from clinical trials indicate that the monthly combination injection, the new implants, and the levonorgestrel IUD are highly effective contraceptive methods.¹^,²⁶ In an open-label, nonrandomized, parallel, controlled study of the MPA/E₂C contraceptive injection, no pregnancies occurred among 782 women during the first year of use (13 cycles of 28 days).²⁶ With the two-rod implant, 5-year failure rates of 0.7% were reported in a large clinical trial,⁴⁰ and the one-rod implant has been shown to be effective for 3 years with no pregnancies in a large number of women.⁴¹ A 7-year cumulative failure rate of 1.1% has been reported with the LNG-20 IUD.¹ The vaginal ring appears to have contraceptive effectiveness considerably higher than the diaphragm, approaching that of OCs.⁴² However, no published data addressing the contraceptive efficacy of the estrogen-progestin vaginal ring or the transdermal patch are currently available.

TABLE 7. Comparison of Available and Prospective Contraceptive Methods

Parameter	Monthly Injection	Implants	LNG-20 IUD	Vaginal Rings	Transdermal Patch	Sponge
Efficacy	High	High	High	Intermediate, some user dependence	Intermediate, some user dependence	Similar to other barrier methods
Length of protection	1 mo	3---5 yr	5---7 yr	1 mo	7 days	Single use with coitus
Rapid return of fertility	Yes	Yes	Yes	Yes	Yes	Yes
Regular cycles	Yes	Variable	Yes, most users	Yes, user controlled	Yes	Yes
Amenorrhea	Uncommon	Variable	Variable	No	No	No
Appropriate in nursing, mothers	Unknown	Yes	Yes	No	No	Yes
Procoagulant	No	No	No	May be less so than oral contraceptive	Unknown	No
Noncontraceptive benefits	Unknown	Unknown	Reduces menorrhagia	Unknown	Unknown	May reduce risk of STDs
Provider required to initiate	Yes	Yes	Yes	Yes (Rx)	Yes (Rx)	No
Provider required to discontinue	No	Yes	Yes	No	No	No
Privacy	Yes	Seen or felt by some users	Usually (string may be felt by partner)	Yes, can be removed before intercourse	No	No

LNG, levonorgestrel; IUD, intrauterine device, STD, sexually transmitted disease.
(Adapted from Mishell DR, Arias RD, Darney PD et al: Contraception in the US: New methods = wider choices. Contemp Obstet Gynecol Suppl:1---26, 2000.)

These new contraceptive options will be valuable additions to the menu of contraceptive choices that clinicians can offer their patients. With the monthly combination injection, US women will have a shorter-acting alternative to DMPA. Although monthly injections are required, menstrual cycles are regular and there is a rapid return to fertility following cessation of use. Moreover, because estradiol cypionate does not increase hepatic globulin synthesis, no significant procoagulant effects have been seen in users of the monthly combination injection.²⁸ The new second generation implants are much simpler to insert and remove than the first generation six-rod system, and their initial acceptance by patients and clinicians in many European countries has been excellent.⁴² Amenorrhea rather than irregular bleeding is generally seen with these products, which is acceptable to an increasing number of US women.⁴² These improvements may lead to a renaissance of interest in contraceptive implants among US clinicians and patients.

With the LNG-20 IUD, progestin is released more slowly and acts locally on the endometrium.⁴² Thus, there is less bleeding and indeed often amenorrhea occurs, making this a useful contraceptive option to reduce menstrual blood loss in women with menorrhagia, including those with bleeding dyscrasias. This progestin-releasing IUD also provides endometrial protection in menopausal women using estrogen, with few of the side effects related to systemic progestin use. The vaginal ring releases a low dose of hormones continuously when in place. Although designed to be removed for 7 days after 3 weeks of use, it can remain in place for longer periods, enabling a woman to control the timing of menses. The device is smaller than the diaphragm; because it is a one-size-fits-all product, no fitting is required. The ring should be an attractive contraceptive option for a substantial number of women. Like the vaginal ring, the new estrogen/progestin transdermal patch provides efficacy and cycle control similar to that of OCs without the need for daily pill-taking.⁴²

A dedicated formulation became available in the United States in 1998 for emergency contraception. With Preven, the marketed version of the Yuzpe regimen, two tablets of a 50 μg-estrogen/progestin OC are taken 12 hours apart. Recently, a progestin-only method—Plan B—was approved. With Plan B, two 750-mg tablets of levonorgestrel are taken 12 hours apart. Plan B is reported to be 85% effective with a pregnancy rate of less than 2%.⁴² An advantage of the progestin-only method is that it causes fewer gastrointestinal side effects than the older method. Today, some clinicians provide every patient at risk for pregnancy with an advance prescription for emergency contraception. This strategy increases the likelihood that women will use emergency contraception when they need it and represents an important tool for reducing unintended pregnancies.

CONCLUSIONS

Effective contraception benefits both mothers and children by decreasing morbidity and mortality, improving the social and economic status of women, and improving the relationship of the mother with all her children. Despite the availability of effective, reversible methods of contraception, the United States has rates of unintended pregnancy and abortion more resembling those of a developing country than other industrialized nations. Among US couples, 40% choose male or female sterilization as their method of contraception, whereas in developing nations where access to female sterilization is limited, the IUD is the most popular method. In more developed countries, the OC is the most popular method of birth control, followed by the condom and the IUD.

Heavy reliance on sterilization by U.S. couples reflects the lack of contraceptive choices and the mistaken belief that this surgical method is “foolproof.” In fact, failure rates with various methods of tubal sterilization have been underestimated; this method is no more effective than injections, IUDs, or implants. The negative media attention focused on problems with reversible methods has also contributed to overuse of sterilization. An additional factor is that most health-care plans cover sterilization whereas only 49% of typical indemnity plans cover the cost of OCs, IUDs, diaphragms, or contraceptive implants and injections. Plans that provide coverage of prescription drugs often do not cover OCs.

New contraceptive methods likely to become available in the US soon will increase the number of effective, reversible contraceptive choices for US couples. Greater access to a wider variety of methods will increase contraceptive use. Much as a good cafeteria offers a wide selection of foods to accommodate a variety of tastes, so too, must clinicians be able to offer women safe, effective, convenient options that meet their individual needs and preferences. The availability of a greater number of contraceptive choices will increase the use of more effective methods and thus has the potential to reduce unintended pregnancies and abortions in U.S. women of all ages.

REFERENCES

1. Grimes DA (ed): The Contraception Report. 10:1–30, 2000

2. Huezo CM: Current reversible contraceptive methods: A global perspective. Int J Gynecol Obstet 62 (Suppl 1): S3– S15, 1998

3. Barber JS, Axinn WG, Thornton A: Unwanted childbearing, health, and mother-child relationships. J Health Soc Soc Behav 40: 231– 257, 1999

4. US Centers for Disease Control and Prevention: Achievements in Public Health, 1900–1999: Family Planning. MMWR Morb Mortal Wkly Rep 48:1073–1080, 1999

5. Baird DT, Glasier AF: Hormonal contraception. N Engl J Med 328: 1543– 1544, 1993

6. Speroff L: A quarter century of contraception: Remarkable advances, increasing success. Contemp Ob/Gyn May 15, 1998

7. Dicfalusy E: The contraceptive revolution. Contraception 61: 3– 7, 2000

8. Parker Jones K: Oral contraception: Current use and attitudes. Contraception 59 (Suppl 1): 17S– 20S, 1999

9. Piccinino LJ, Mosher WD: Trends in contraceptive use in the United States: 1982–1995. Fam Plann Perspect 30: 4– 10, 1998

10. Kaunitz AM: Long-acting hormonal contraception: Assessing impact on bone density, weight, and mood. Int J Fertil 44: 110– 117, 1999

11. Martin K, Wu Z: Contraceptive use in Canada: 1984–1995. Fam Plann Perspect 32: 65– 73, 2000