Roxanne M. Jamshidi
Contraception provides a woman and her partner with the ability to determine the number and timing of pregnancies. Generally, avoidance of unwanted pregnancies and continued consistent use of a contraceptive method are issues that require ongoing management and consultation rather than an isolated decision.
There are many contraceptive methods. It is important to understand the benefits and limitations of all of them to be able to educate the patient fully about her options. The caregiver should be prepared to deal with women who have varying knowledge and experience about contraception. Table 100.1 lists the most recent data regarding the percentage distribution of use of contraceptive methods by women in the United States (1).
Table 100.2 shows the failure rates of various methods of contraception. Perfect use refers to the annual percentage of unexpected pregnancy among couples who use the method correctly and consistently, whereas typical use
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reflects common irregularities in use other than voluntary termination of the method. Clearly there is very little difference between the two failure rates with some methods, whereas others show a considerable difference. This information should be used in helping to educate the patient.
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TABLE 100.1 Contraceptive Use among U.S. Women 15–44 Years of Age, 2002 |
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Once it is established that a woman desires fertility regulation, a focused medical history should be obtained, including information about past pregnancies, menstruation, smoking, and medical problems that may affect selection of one method over another. A blood pressure measurement should be made, and if history alone cannot rule out pregnancy, a urine pregnancy test performed. A pelvic examination is not immediately necessary for the initiation or continuation of birth control with the exception of placement of an intrauterine device (IUD) or fitting for a diaphragm or cervical cap. Although an annual pelvic examination, breast examination, Pap smear, and screening for sexually transmitted diseases (STDs) are seen as necessary steps in preventive health care for women of reproductive age, and their deferral should not preclude prescription of a safe contraceptive method and risk an unsafe or unwanted pregnancy (2). After the evaluation, the physician and patient (and, sometimes, her partner) are ready to discuss the various contraceptive methods and develop a satisfactory plan.
Systemic Hormonal Contraception
Combined Oral Contraceptive Pills
Mechanism of Action
The primary contraceptive action of combined oral contraceptives (COCs) is suppression of ovulation by inhibition of gonadotropin-releasing factors in the hypothalamus. This action is primarily mediated by the progestin component. The principal effect of this inhibition appears to be suppression of the surge in activity of luteinizing hormone at midcycle, thereby removing a major stimulus to ovulation. Additionally, COCs make cervical mucus more viscous and therefore less easily traversed by sperm. They also have a direct effect on endometrial development in high doses, making the uterus less receptive to ovum implantation (3).
Preparations and Dosage Schedules
The COC was first introduced for use in the United States in 1960. In the ensuing years, significant changes were made in steroid dosages and some new steroids were introduced. Since 1970, all new COCs introduced in the United States have contained ethinyl estradiol as their estrogen. As their progestin, many COCs in current use contain levonorgestrel or norethindrone. In 1992, however, two new progestins, norgestimate and desogestrel, were introduced in the United States in an effort to decrease unwanted side effects of oral contraception. A more recently introduced progestin, drospirenone, which is derived from 17 α-spirolactone, has both progestogenic and antimineral corticoid activity.
There are three different preparations of oral contraceptive pills:
Table 100.3 lists conditions requiring precautions for the use of COCs. If a woman chooses oral contraception and has no clinical contraindications, then the first choice should be a combination preparation containing between 20 and 35 µg of estrogen. Use of pills containing 50 µg of estrogen should be avoided, and the few women who may need them should be evaluated by an obstetrician-gynecologist if the clinician is not fully familiar with their use. The choice of progestin is less critical, and no progestin is clearly superior to another. The newer progestins have structural modifications that lower their androgenic activity, and therefore may cause less hirsutism, acne, and weight gain, as well as a more favorable lipid profile. Because of the potassium-sparing effects of drospirenone, caution should be used for women at risk for hyperkalemia.
To suppress ovulation and yet allow periodic bleeding, the combination tablet is taken every day for 3 weeks. COCs are generally packaged in 21-day or 28-day cycles.
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The 28-day pack is designed to improve patient compliance by providing seven placebo pills at the end of the pack. An exception to this is a combination pill that adds a small dose of estrogen to the pills taken on the last 5 days, instead of using inert pills, to prevent the estrogen withdrawal headache experienced by some women. An extended regimen package that contains 84 days of active hormone followed by 7 days of placebo (Seasonale) is also available. The drop in hormone level after 21 (or 84) days produces withdrawal bleeding, just as it does in the normal menstrual cycle. Women typically have their menses 2 to 3 days after finishing their active pills.
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TABLE 100.2 Summary of Methods of Contraception, Their Mechanisms of Action, Failure Rates, and Major Adverse Effects |
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Traditional initiation of COC use has the woman start the medication by the fifth day of her cycle, counting the first day of menstrual bleeding as day 1. More common practice is to start on the first Sunday after the onset of a
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menstrual period. This latter practice allows the packaging of the tablets to provide a minicalendar, which minimizes missing a dose. The tablets are arranged in circles or rows, making it easier to use them regularly. Another method of initiation that may improve compliance is “quick start,” which has the woman take the first pill at the time of COC prescription (e.g., in the clinic) (4).
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TABLE 100.3 Conditions Requiring Precautions for the Use of Oral Contraceptives |
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Postpartum women choosing a COC should wait 3 weeks because of the theoretical increased risk of thromboembolism after pregnancy, but no longer than 4 to 6 weeks, at which time ovulation typically resumes. For women who are breast-feeding, COCs are usually avoided because the estrogen may decrease the quantity of breast milk. Women who have had a spontaneous or therapeutic abortion may start taking the drug immediately after the event.
Noncontraceptive Benefits
In the past few years, COCs have been found to be associated with a significant number of beneficial side effects. These include decreased risks for benign breast tumors, functional ovarian cysts, acne vulgaris, dysmenorrhea, anemia, pelvic inflammatory disease (PID), endometrial carcinoma, and carcinoma of the ovary. Recognition of the noncontraceptive benefits of COCs helps place them in a much more positive perspective for women and, indeed, puts the risk–benefit ratio of COCs in a more proper perspective.
Limitations
Thromboembolic Disease
In the late 1960s, epidemiologic studies conducted in Great Britain and the United States showed an increased risk of thromboembolic disorders and myocardial infarction (MI) among COC users. It was quickly determined that the risk of venous thromboembolism (VTE) and other vascular accidents was related to the dosage of estrogen, the woman's age, and whether she was a smoker or nonsmoker (5,6). Decreasing the estrogen dosage in the COCs from 80 to 50 µg achieved a reduction of approximately 30% in the incidence of thromboembolic disease. A further reduction from 50 µg into the range of 30 to 35 µg further decreased the risk of venous thrombosis and other serious vascular complications.
The risk of thromboembolic disease must be kept in perspective. The general risk of thromboembolism in a nonpregnant woman of reproductive age is about 5 to 10 per 100,000. For women taking COC preparations the risk is about 15 to 40 per 100,000. However, for a woman who is pregnant the risk is 60 per 100,000 (7). The increased risk of VTE is highest in the first year of COC use and declines thereafter (8).
Approximately 10 million women in the United States use COCs. Cardiovascular problems, heart attack, stroke, VTE, and pulmonary emboli are the main causes of serious morbidity and death associated with COC use (9,10). Therefore, women with a history of thromboembolism, stroke, or ischemic heart disease should not use COCs. Women who are older than 35 years of age and smoke should not use COCs because of the risk of cardiovascular disease. Smokers who are younger than 35 years of age are not prohibited from using COCs if it is the best method for them; they should, of course, be encouraged to quit smoking (11).
The risk of VTE associated with inherited thrombophilias is further increased with COC use. Women with the factor V Leiden mutation, the most common thrombophilia, who use COCs experience a risk of VTE 30 times higher than non-COC users who are not carriers of this mutation (12). Universal screening for thrombophilias among women who may start COCs is not, however, cost effective. Currently, screening for these mutations prior to initiating COCs is recommended only for women having a personal or family history of thrombosis (13) (see Chapter 57).
The procoagulant changes induced by COCs do not substantially resolve until 6 or more weeks after COC discontinuation (14). For women undergoing major surgery, the risks associated with continuing COCs until surgery must be balanced against the risks of an unintended pregnancy if COCs are stopped 1 month or more before major surgery (15). Heparin prophylaxis should be considered for current COC users having major surgical procedures. COCs need not be discontinued before minor surgery (16).
Hypertension
With the older high-dose COCs, the risk of developing high blood pressure was approximately 7%. Clinical trials
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have shown that low-dose COCs (20 to 35 µg of estrogen) are responsible for only small changes in blood pressure. Therefore, if a COC user develops hypertension, the hypertension should be evaluated and not ascribed to contraceptive use. Women with pre-existing mild hypertension and those who develop mild hypertension while taking COCs and are younger than the age of 35 may safely use COCs if their blood pressure is monitored and controlled. Severe hypertension or hypertension with end-organ vascular disease is a contraindication to the use of COCs (11).
Neoplasia
After almost 35 years of contraceptive use, the data concerning the relationship between COC use and neoplasia are mostly reassuring. There is a relationship between the long-term use of COCs and the development of benign hepatic neoplasia (17). These lesions are rare, and although the increased relative risk in long-term users is high, the absolute incidence is very low. Long-term use of COCs has been associated with a significantly decreased incidence of endometrial and ovarian cancer (18, 19, 20, 21, 22, 23). A meta-analysis of 20 studies examining the risk of ovarian cancer reported a 10% to 12% decreased risk with 1 year of COC use, and a 50% decreased risk after 5 years of COC use (19). The longer COCs are used, the more they appear to protect from ovarian cancer (20). This protective effect of COCs appears to extend to women at risk for hereditary ovarian cancer, such as those associated with mutations in the breast cancer gene 1 (BRCA 1) and breast cancer gene 2 (BRCA 2) (21). Women who use COCs at least 12 months have a decreased relative risk (RR = 0.6) of developing endometrial cancer compared to never users (22). This risk of endometrial cancer is significantly decreased with increasing duration of OC use, and persists even 20 years after discontinuation (23).
The data are inconclusive for malignant melanoma and cervical neoplasia. With regard to the development of cervical neoplasia, several studies show a slightly increased risk directly related to length of COC use (24, 25, 26). However, because the human papilloma virus (HPV) has been shown to be the main causative agent in cervical cancer, COC use most likely acts as a cofactor in the development of the disease (27).
Similarly, data regarding breast cancer and COC use are conflicting and no conclusions are currently possible (28). Although some data suggest that COCs may advance premenopausal breast cancer, this is a rare time for its occurrence. A pooled analysis from 54 studies shows a small increase in the RR (1.24) of localized breast cancer associated with current COC use and with COC use within 1 to 4 years (RR = 1.16) compared to controls. This risk declines soon after stopping use and disappears within 10 years. Additionally, the breast cancers diagnosed in COC users were significantly less advanced than those in women who never used COCs (29). The incidence of benign breast tumors and fibrocystic disease is reduced by the administration of high-progestin-dose COC hormones. Data on the newer, low-dose progestin contraceptive pills are inconclusive (30).
Altered Metabolism of Glucose or Lipids
With the COCs that contain more than 50 µg of estrogen, abnormal glucose tolerance tests can be seen after 3 months of use. However, this reduction in glucose tolerance is not seen with the low-dose preparations. Also, the new triphasic and low-dose forms do not appear to alter the lipid profile even in long-term users, whereas the high-dose preparations (more than 50 µg of estrogen) do adversely affect the lipid profile (31,32).
Gallbladder Disease
The incidence of symptomatic gallbladder disease may increase up to twofold within the first 1 to 2 years of OC use. An estrogen-associated increase in the concentration of cholesterol in the bile has been demonstrated in women taking COCs and may be the pathogenetic mechanism.
Headaches
Migraine headaches have been reported to worsen, improve, or not change in women taking COCs. Typically, if migraines do occur during COC use, it is during the hormone-free interval. The development or worsening of severe recurrent headaches is a reason to recommend another contraceptive method. Women with a history of migraines associated with auras, or with migraines and comorbid conditions, should avoid the use of COCs because of the increased risk of ischemic stroke (33).
Birth Defects
It is unlikely that hormonal ingestion during the first 3 months of pregnancy results in the subsequent development of birth defects. Although initial epidemiologic studies done in the 1960s and early 1970s seemed to favor an association with some cardiovascular and limb defects, more recent studies tend to refute this association. There is no evidence that prior use of contraceptives has any effect on the development of any birth defect. Establishing a pregnancy within one to two cycles after discontinuation of COCs is not associated with a higher incidence of birth defects (34,35), so no period of protection with another contraceptive method is needed when pregnancy is desired.
Other Side Effects
In general, minor side effects occur early in the course of taking COCs and may be transient. Thorough education by
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the physician increases the likelihood that the woman will tolerate these effects and continue taking the medication.
Alopecia
Alopecia is a rarely reported side effect (see Chapter 115). Most often it is transient; but if hair loss for longer than 3 months is reported, the drug should be discontinued and the woman should use some other form of contra-ception.
Nausea
Nausea occurs in approximately 5% of women, typically resolves within 3 months after initiation of COC use, and almost always can be eliminated by taking the contraceptive at bedtime.
Fatigue
Increased fatigability is occasionally described by COC users, but usually it is of short duration.
Change in Menstrual Flow
The most typical pattern is a reduction in the amount and duration of menstrual flow, which often is a welcomed effect. Because COCs cause the development of only a thin endometrium, amenorrhea can occur in 5% to 10% of cycles while on COCs. When this occurs and the woman has taken the OC regularly (so that pregnancy is not likely), she can be advised to continue the pills for another cycle. If she is again amenorrheic, a pregnancy test (discussed under Diagnosing Pregnancy) should be done. If pregnancy is ruled out, she can either select another contraceptive method, change the COC preparation to one containing more estrogen, or be reassured that if she continues taking the method correctly she will remain amenorrheic.
Breakthrough Bleeding
Breakthrough bleeding is the most common side effect of COCs, and is most likely during the first three cycles after initiation. It is of no concern as long as the woman has not missed a dose. Failure to take daily doses increases the chance of breakthrough bleeding, particularly in the early part of the cycle. If breakthrough bleeding continues for several cycles, referral to a gynecologist is indicated to rule out an organic cause and to consider use of a higher dosage of estrogen or other change in formulation.
Weight Gain
Although a small amount of weight gain (sometimes associated with fluid retention) is possible with COC use, a systematic review of the available data excludes a large effect of oral contraceptive use on body weight (36).
Vaginitis
It has been difficult to document a close relationship between COCs and vaginitis. The hormones do alter the vaginal milieu, but vaginitis develops in only a small proportion of women. Standard diagnostic methods and subsequent therapy (see Chapter 102) allows most women to continue to use the COC.
Skin Changes
Some women, especially dark-skinned ones, note chloasma (yellowish-brown discoloration of the skin) and a change in hair texture. Chloasma is unlikely to resolve with continued administration of the COC and is therefore a reason to discontinue it if the cosmetic effect is un-acceptable.
Emotional Changes
Typically, COCs improve depression and premenstrual irritability. In some women, however, the progestin agent can cause or exacerbate depression. Women who have a history of depression should be monitored especially carefully for recurrence or exacerbation of this problem. If depression develops or worsens and is thought to be caused by the COC, the medication should be discontinued.
Effects on Laboratory Tests
COCs can alter the results of a number of laboratory tests (37). The alterations reflect physiologic changes in most instances but rarely signify clinically significant disease.
Drug Interactions
COCs may alter the effectiveness of a number of other drugs; conversely, a number of other drugs may alter the effectiveness of COCs. Generally, concomitant use of antibiotics with the exception of rifampin does not decrease COC effectiveness. However, individual women have been reported to have significant decreases in plasma concentrations of ethinyl estradiol when taking certain other antibiotics (e.g., tetracycline, penicillin derivatives, cephalosporins), and for this reason, women should be informed of this small risk (38). Caregivers should investigate the possibility of drug interaction before prescribing any other medication to a woman using a COC preparation. Table 100.4 lists drugs that may interact with COCs.
Instructions
Women should take the pills at the same time each day. If a single pill is missed, she should take the missed pill as soon as she remembers it. If two or more pills have been forgotten, she should take two pills a day until she has caught up and then continue the normal regimen but use a backup method (i.e., condoms) for 1 week.
Followup
A woman taking COCs should see a practitioner once a year for a pelvic examination and a cervical smear for cytology if indicated, but inability to schedule these evaluations should not be a reason to withhold a contraceptive
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prescription. Screening for STDs (see Chapter 102) may need to be done if the woman is at risk. COCs may be discontinued at any time if pregnancy is desired or another method of contraception is planned. The first few menstrual periods after withdrawal may be heavier than during the time COCs were used. There is no change in fertility after a course of COCs, regardless of duration of use. A pill-free or rest period is not advocated when switching to another method or in anticipation of becoming pregnant.
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TABLE 100.4 Selected Drugs That May Interact with Oral Contraceptive Preparations (OCs) |
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Contraceptive Patch
An alternative method of delivering combined hormonal contraception is in the form of a transdermal patch (Ortho Evra). This thin medicated adhesive is applied to the buttocks, abdomen, upper outer arm, or upper torso (excluding the breast area), and delivers 20 µg of ethinyl estradiol and 150 µg of norelgestromin per day (39). The patch is changed weekly for three weeks, followed by a patch-free week for a withdrawal bleed.
The same side effects and cautions that apply to traditional COCs also apply to the contraceptive patch, with the exception of a higher incidence of application site reactions (20.2%), breast symptoms during the first 2 months (18%), and dysmenorrhea (13%) (40). Because the medication in the transdermal patch is in the adhesive itself, excellent attachment is required. Data on patch adhesion show that approximately 4.7% of patches need to be replaced because of either partial or full detachment (40). The efficacy of the patch is comparable to COCs, with a failure rate of less than 1% (40,41). Clinical data indicate that contraceptive efficacy may decrease in women weighing more than 90 kg (198 lb) (42), however, even low-dose COCs may have decreased efficacy among heavy wo-men (43).
Vaginal Ring
The combined contraceptive vaginal ring (Nuva Ring) is another novel method of delivering the same hormones as those used in COCs. The vaginal ring is a flexible transparent copolymer ring that is placed in the vagina continuously for three weeks, and then removed for a week to allow for a withdrawal bleed. The vaginal ring delivers 15 µg of ethinyl estradiol and 120 µg of etonogestrel daily (44). Although the ring is designed to be worn continuously for 3 weeks, it can be removed for up to 3 hours at a time, without decreasing effectiveness. Additionally, serum concentrations of the hormones remain at contraceptive levels through 5 weeks of continuous use if the ring is left in the vagina. The ring does not have to be fitted or placed in a specific location in the vagina, can be worn during intercourse, and is comfortable for both the patient and her partner. In fact, the vaginal ring can be used concomitantly with tampons, spermicide, or antimycotic comedication without adverse effects or decreased efficacy (45,46,47).
Again, as a combined hormonal method of birth control, the same side effects and cautions which apply to traditional COCs also apply to the vaginal ring. Initial trials showed excellent cycle control with a low incidence (fewer than 5% of women) of irregular bleeding when initiating the vaginal ring. Some side effects are unique to the ring, including an approximate 5% incidence in increased vaginal discharge, 5% incidence of vaginitis, and 2% incidence of vaginal discomfort. Overall, however, acceptability for the ring is quite high for both patients and their partners, with over 90% of users recommending the method to others (48).
Progestin-Only Pill
Because the progestin-only pills are associated with decreased effectiveness and increased breakthrough bleeding compared to COCs, they are rarely prescribed. However,
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progestin-only contraceptive pills offer an option for women who have medical conditions contraindicating estrogen (such as thrombophilia), are intolerant to estrogenic side effects, or who are lactating.
Injectable Contraception
Depot medroxyprogesterone acetate (DMPA) (Depo-Provera), a synthetic progestogen that is similar to natural progesterone, has been in use in the United States since 1992. DMPA is administered as an intramuscular injection of 150 mg that provides contraceptive efficacy for at least 14 weeks. Administration every 12 weeks provides a margin of error should the woman fail to return at the exact appointed time. In this dosage, the failure rate is comparable to that of sterilization. DMPA acts by inhibiting ovulation, thickening cervical mucus, and altering the composition of the endometrium secondary to the progestin effects.
The most common side effect associated with DMPA is a disruption in the menstrual pattern. This disruption is unpredictable and can range from prolonged periods of amenorrhea (common) to episodes of heavy bleeding (rare). Approximately 50% of women using DMPA for 1 year develop amenorrhea (49). Other reported side effects include skin changes such as acne, breast tenderness, headache, and psychological effects such as decreased libido, depression, nervousness, and fatigue. Variable effects of DMPA IM on body weight have been reported, ranging from nonsignificant changes, to gains of approximately 3 kg to 4 kg at 1 year. However, the only placebo-controlled prospective trial evaluating this issue showed no relationship between DMPA use and weight changes (50).
DMPA is associated with increased bone resorption and, in some studies, a small but statistically significant decrease in bone density when used for more than 2 years. Although this effect appears to be transient and largely reversible (51), the U.S. Food and Drug Administration (FDA) issued a “black box” warning regarding the possible effects of DMPA on bone mineral density (52). In contrast to the FDA, the World Health Organization (WHO) does not believe there should be any restrictions on the use of DMPA (53). Nevertheless, patients should be counseled regarding the recommendation for adequate calcium intake, especially among adolescents. Additionally, women who may be planning to try to conceive in the future should be counseled regarding the delay in ovulation of up to 18 months after cessation of DMPA, although most women have return of fertility 6 to 9 months after the time the next injection would have been given.
A new lower dose (104 mg) DMPA formulation that can be given subcutaneously is undergoing clinical trials. This method of administration offers the advantage of potential self-administration.
A monthly injectable contraceptive combining 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate was approved by the FDA in 2000, and marketed under the name Lunelle. Its mode of action is similar to that of COCs, as are the precautions for prescribing the method (54). The side effect of irregular bleeding is decreased compared to DMPA, and there is a rapid return to fertility within 2 months after the last injection. Unfortunately, Lunelle was recalled by the manufacturer in October 2002, with no known plan for re-introduction to the U.S. market.
Subdermal Contraceptive
Implantable, subdermal capsules that release progestins for several years provide long-acting, reversible contraception. Implants offer the advantage of extremely high effectiveness without maintenance of the user. Like other progestin contraception, the mechanism of action is through a combination of suppression of ovulation, changes in the cervical mucus that make it impenetrable to sperm, and changes to the endometrium that make it thin and atrophic. Implants offer rapid onset of action, with cervical mucus changes seen within hours of placement (55). In general, implants can be placed during any time of the menstrual cycle, with use of backup contraception for the first week of use only. After removal of implants, former patterns of ovulation and menses return rapidly (56). Former use of implants does not alter subsequent rates of fertility, miscarriage, stillbirth, prematurity, or congenital malformations (57).
Like other progestin methods of birth control, the most common side effect with implants are menstrual changes, occurring in almost three quarters of users in the first year (58). Bleeding patterns often become irregular, with an overall decrease in blood loss. Amenorrhea is not uncommon as well. Less common side effects of implants include headaches, weight gain, acne, and psychiatric or mood changes. Local skin irritation occurs in approximately 5% of implant users, but actual infection or inflammation is much less common (59).
In the United States, no implantable methods of birth control have been available since the six-rod implant (Norplant) was removed from the market in 2001. Containing 216 mg of levonorgestrel in six rods, Norplant was approved for use for 5 years in the United States, but two large studies have shown cumulative 7-year pregnancy rates comparable to surgical sterilization, with some decreased efficacy in women weighing more than 80 kg (60,61). Experience with Norplant has led to improvements in the contraceptive implant system, primarily by decreasing the number of implants from six to one or two. Systems with fewer implants can be inserted and removed faster and more easily. Norplant II (Jadelle) is a two-rod system containing 150 mg of levonorgestrel that is left
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in place for 3 to 5 years. FDA approval was obtained in 1996; but no plans exist to market this system in the United States. However, pending FDA approval, a new single rod system implant should be available in the United States in 2006. This system, Implanon, contains the progestin etonogestrel, which has less androgenic and more progestational activity then levonorgestrel. The single rod comes in a disposable trocar/inserter, which aids subdermal placement. The duration of use is designed for 3 years. With initial studies showing only one pregnancy in over 70,000 cycles, Implanon has extremely high contraceptive efficacy (62).
Intrauterine Contraceptives
Intrauterine contraceptives are one of the most effective methods of contraception. Pregnancy rates range from 0.14 to 3 per 100 women per year. The first modern IUDs appeared in the early 1960s and were made of a biologically inert plastic. The second-generation copper and progesterone-containing devices have been available since the early 1970s (63,64).
During the late 1970s, serious concerns were raised regarding the safety of all IUDs. Studies showed a strong relationship between IUD use and the development of PID. The Dalkon Shield specifically was removed from the market because of its link to spontaneous septic abortions and PID. The clearly increased risk for infection with this particular product has been attributed to the multifilament tail (the string that hangs into the vagina), which seemed to act as a wick for bacteria. (Other IUDs used a monofilament tail.) Because of the publicity from the Dalkon Shield, distribution of other devices was discontinued by manufacturers because of low sales volume or concern regarding litigation costs. However, the concern regarding an increased risk of infertility from PID associated with modern IUD use appears to be unfounded. Epidemiologic studies in the 1970s tended to overstate the risk of pelvic infection from IUD use, for the following reasons:
Types
Two types of IUDs are available in the United States: progesterone-releasing and copper-bearing. All of the devices have a monofilament string attached, which allows for surveillance and removal (see Followup Care). Return to fertility is rapid for both types of IUD.
The copper IUD (ParaGard T380A), which contains no hormone, has a body of polyethylene wound with copper wire and a copper collar on each of its transverse arms. The copper inhibits sperm motility and capacitation, making them unable to penetrate the ovum. There is no evidence that IUDs work after fertilization as an abortifacient. Currently the ParaGard is approved by the FDA for at least 10 years of continuous use. It has a cumulative 10-year failure rate of 2.1% to 2.8%.
The hormone-releasing intrauterine contraceptive the Mirena intrauterine system, was approved by the FDA in 2001. The Mirena has a small, T-shaped frame with a steroid reservoir that releases levonorgestrel at the rate of 20 µg per day. It is currently approved for 5 years of continuous use and has an overall failure rate of 0.14 per 100 woman-years, comparable to that of sterilization. The levonorgestrel thickens cervical mucus and suppresses endometrial proliferation to inhibit passage of sperm, in addition to altering sperm transport as a result of the presence of the IUD in the uterine cavity. The progestin exerts a predominantly local effect; therefore, plasma concentrations of levonorgestrel are lower for Mirena users than for women using oral pills or implants.
Use and Insertion
If the clinician is not experienced in IUD insertion, the woman should be referred to a gynecologist. Traditionally, the IUD is inserted at the time of menstruation, to assure that the woman is not pregnant. However, as long as the provider can be reasonably certain that the woman is not pregnant, the IUD can be inserted at any time of a menstrual period. Prophylactic antibiotics given at the time of insertion do not provide any benefit (67).
Women typically experience some cramps when the IUD is inserted; these can be limited by the administration of nonsteroidal analgesics before the insertion (e.g., ibuprofen 400 mg). If significant cramps persist beyond a few hours, this may be an indication that the device is not inserted properly and should be removed.
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After insertion, the woman should feel the string of the IUD. She repeats this monthly, after each menstrual period, to ensure that the device is in place.
Bleeding Patterns
Copper IUD users typically note increased menstrual bleeding, and some experience cramping, which usually subsides within 3 months. Conversely, levonorgestrel IUD users experience a substantial decrease in their menstrual bleeding and cramping. The average number of bleeding days decreases from 5 in the first month to 1 in the sixth month; between 15% and 20% of women are amenorrheic by the end of the first year of use (68,69). This bleeding pattern has prompted the noncontraceptive use of this method for women with irregular bleeding.
Adverse Effects
The most common adverse effects of the IUD are cramping, abnormal uterine bleeding, and expulsion. Expulsion occurs in approximately 5% of users, and is the most common reason for IUD failure (70). Uterine perforation, a rare complication, is most likely to occur at the time of insertion. Although the risk of PID does not increase with prolonged IUD use, the first 20 days after insertion is associated with a small increased risk of infection, presumably from endometrial contamination at the time of insertion (71). After IUD insertion, the woman must be instructed to report any fever, pelvic pain, or discomfort promptly. Copper IUD users must also report any missed menstrual periods and be evaluated for pregnancy (including ectopic pregnancy); however, this does not hold true for levonorgestrel IUD users.
Followup Care
A followup visit should be scheduled after the patient's next menstrual period to check IUD placement and evaluate for signs of infection. Thereafter, the woman can return to annual well-women visits. The followup is best done by a gynecologist if the clinician is not experienced in examining women with an IUD.
If the IUD strings are not visualized on speculum examination, the first step in evaluation is to perform a pregnancy test. Those users found to be pregnant should be promptly referred to a gynecologist for evaluation. If the woman is not pregnant, a cytobrush can be inserted in the endocervical canal to draw out the strings. If this is not successful, the endocervical canal can be examined using a uterine sound or an endocervical speculum. It the IUD is present in the cervix, it should be removed. If the IUD is not in the cervix, radiography or ultrasonography (US) should be used to localize the IUD.
Generally, the IUD is easily removed by gentle traction on the string. As with other methods, if the woman terminates this form of contraception other than to attempt pregnancy, she will need help in choosing another form of contraception.
Barrier Methods
Diaphragm
The diaphragm is a low-cost patient-dependent contraceptive device. It is a dome-shaped rubber device that is held open by a metallic band or spring. It is filled with a spermicidal cream or jelly before each use and placed in the vagina over the cervix to prevent sperm deposited during ejaculation from reaching the cervical os. As seen in Table 100.2, with typical use the failure rate is high, whereas correct or ideal use results in a lower failure rate, as is true of all barrier methods.
The diaphragm is fitted by the medical provider. The device fits between the posterior fornix and the symphysis. The largest device that is comfortable is the proper one to use. For better effectiveness, the woman should be asked to insert the diaphragm in the office and have the provider check its placement. Manufacturers of diaphragms have excellent booklets that are useful in helping a woman acquire the skill necessary for comfortable use of this form of contraception.
The woman applies spermicidal jelly to the inside of the dome and inserts the diaphragm in the vagina as long as 4 hours before intercourse. She should check for position with her finger and allow the device to remain in place for at least 6 hours after coitus. If repeated intercourse occurs within 6 to 8 hours, additional jelly should be placed in the vagina first, without removal of the diaphragm.
With care a diaphragm should last 2 years. The woman will need a new fitting if she gains or loses significant weight, has a baby, or has pelvic surgery. Some women report discomfort while the diaphragm is in place. This discomfort is most often related to a wrong design or to improper fitting, and re-evaluation usually identifies the problem. A few women develop recurrent cystitis with frequent diaphragm use; this should lead to a discussion of alternative methods of contraception.
Cervical Cap
The latex Prentif cervical cap is about as effective as the diaphragm (in nulliparous women), offers the advantage of being able to be left in place for a longer time (up to 48 hours), and does not need to be used with spermicide. However, the addition of a tablespoon of spermicide placed in the cap prior to insertion can improve efficacy and decrease the incidence of foul-smelling discharge common after 24 hours of use. The cervical cap comes in several sizes, and must be fitted by a health professional to go over the cervix. Proper fitting can be accomplished in approximately 80% of women. Compared to the diaphragm,
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the Prentif cervical cap is somewhat harder to fit and is more difficult to insert. Two newer cervical caps have been developed and approved by the FDA: the FemCap and Leas Shield. Both are made from silicone rubber, can be left in place for up to 48 hours, and are designed to be used in conjunction with a spermicide. Unlike the other cervical caps and diaphragms, Leas Shield is “one-size-fits-all.”
Condom
The male condom is a latex rubber sheath that is placed over the erect penis. It is the only reversible effective male method of contraception except for coitus interruptus. Condoms, when properly used, are an effective form of contraception, and their failure rate with experienced and strongly motivated couples is as low as 1 or 2 per 100 couple-years of exposure. However, rates during the first year of use or in less motivated couples may be considerably higher. Its effectiveness can be enhanced if it is combined with application of a spermicidal jelly or foam in the vagina. Some condoms are being manufactured in containers with a spermicidal lubricant. The condom, when used properly, provides considerable protection against STDs, including gonorrhea, herpes, chlamydia, and human immunodeficiency virus (HIV) infection. Its only side effects are rare instances of sensitivity to the lubricating material or to latex and skin irritation from friction.
The female condom is a disposable, prelubricated polyurethane sheath between two rings of differing sizes. One ring is placed in the vagina, as with the diaphragm, and the larger ring rests exteriorly on the vulva. Studies show that it is impenetrable to the passage of HIV as well as other common STD agents. Expected pregnancy rates are comparable to those seen with male condom use (72).
Sponge
The Today sponge is made of a soft, disposable polyurethane foam which contains the spermicide nonoxynol-9. After it is moistened with water and inserted in the vagina, it becomes effective immediately and remains effective for the next 24 hours without the need to add spermicidal cream, even with repeated acts of intercourse. It does not require fitting and was available in the United States as an over-the-counter (OTC) product until 1995 when it was taken off the market because of manufacturing problems. The Today sponge is again available in the United States as of 2005.
Vaginal Suppositories, Foam, and Jelly
Vaginal suppositories, foam, and jelly contain a spermicidal material combined with cream, jelly, or foam. The material is inserted in the vagina at least 10 to 15 minutes before intercourse. The spermicidal material is dispersed in the vagina and over the cervix. This creates a barrier around the cervical os to prevent sperm from entering the intrauterine cavity. All of these forms of contraception may be obtained without prescription. They are especially useful when additional protection is desired at midcycle with the condom or to increase the effectiveness of the diaphragm when repeated intercourse occurs. The side effects are minor and are related to sensitivity to the spermicidal material.
Natural Family Planning
The rhythm method or periodic abstinence requires avoidance of intercourse during a calculated fertile period. The human ovum probably is viable for only 12 to 24 hours after ovulation, whereas sperm retain the capability for fertilization for 48 hours to 5 days. It is probable that conception is most likely during a 6-day interval ending on the day of ovulation (73). The development of a method of contraception that avoids intercourse at the fertile time is logical; however, the risk of pregnancy in women who use this method of contraception is high (Table 100.2). Three methods have been developed to calculate the fertile period:
Sterilization
In the United States, sterilization is the most popular method of contraception, with elective sterilization higher
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for women than for men (1). Because sterilization is meant to be permanent and nonreversible, individuals and couples considering sterilization need very careful education so that they understand the nature and risks of the procedure and the availability of other contraceptive options.
Vasectomy
Vasectomy, when properly performed, has a very low failure rate. The complication rate is approximately 4 in 1,000, and, for the most part, complications are minor. They include infection, hematoma, epididymitis, and granuloma formation. Long-term serious side effects have not been reported among the very large numbers of men who have had the procedure performed. There was a transient concern, now known to be unwarranted (74), that antibodies to sperm that develop in some men after vasectomy predispose them to atherosclerosis. Additionally, although there had been a concern that the risk of testicular and prostate cancer may be increased in men after vasectomy, data do not support this association (75,76).
Patient Experience
This procedure is done under local anesthesia in the physician's office or outpatient surgical suite. There is minimal operative discomfort. Postoperatively, mild discomfort is common but is usually controlled with a mild analgesic, such as acetaminophen. Vigorous physical activity and sexual activity are restricted for 5 to 7 days until the wound has healed. Followup visits are necessary so that sperm counts can be performed. Usually, 6 to 12 weeks or approximately 20 ejaculations are required for the ejaculate to become free of sperm. Therefore, use of another contraceptive method is necessary until azoospermia is confirmed.
Tubal Ligation
Despite some sterilization failures with tubal ligation, it remains among the best methods of long-term contraception. Overall failure rates are 0.5% at 1 year and approximately 1.8% at 10 years (77). The major complication rate is approximately 4 per 1,000. The complications are bleeding, infection, and bowel, bladder, or uterine trauma.
Patient Experience
Laparoscopy or minilaparotomy in the United States is usually performed with the use of general anesthesia. Uncomplicated tubal ligation is usually performed as an outpatient procedure and is very well tolerated. Mild abdominal discomfort, when present, usually lasts for only a few days, or rarely for a few weeks. Mild analgesics (e.g., acetaminophen) provide relief. The woman typically is able to return to her usual activities in 48 to 72 hours. Sterilization is immediate, and intercourse is permitted as soon as the wound is no longer painful. More recently, a transcervical sterilization technique (Essure) in which tiny nickel-titanium metal coils with polyethylene fibers are inserted into the fallopian tubes hysteroscopically, has become available. Over the next several months after insertion, subsequent growth of local tissue allows scar formation that causes tubal occlusion. Currently, the FDA recommends that women who undergo the Essure method of sterilization continue an alternate form of birth control for the first 3 months after coil placement, at which time a hysterosalpingogram should be performed to confirm tubal occlusion.
Tubal ligation is ideally performed in the first half of the menstrual cycle before ovulation has occurred. This avoids the possibility of fertilization of an ovum occurring a day or two before the surgical procedure. If the woman is using effective contraception, tubal ligation may be performed at any time.
The existence of a posttubal syndrome, characterized by heavier menstrual bleeding and more pelvic pain than in the unsterilized population, has been questioned. After sterilization, most women notice no significant change in symptoms associated with their menstrual periods.
Emergency Contraception
Emergency contraception describes the use of a contraceptive method after intercourse to prevent pregnancy. This name is preferred to “morning-after pill,” which suggests a very brief window of potential use after unprotected intercourse. Emergency contraception is indicated after intercourse without a method, current method failure (e.g., condom rupture), or rape. Access to emergency contraception can be increased by providing a patient with instructions and a prescription during a routine office visit or by making patients aware of how to access it urgently (1-888-NOT-2-LATE or http://www.not-2-late.com). Emergency contraception should not be used if a pregnancy test is positive.
Insertion of a copper IUD, possible up to 5 days following unprotected intercourse, is the most effective form of emergency contraception, with a pregnancy rate of approximately 0.1 per 100 women. Oral contraceptives are also highly effective as emergency contraceptive measures and are used up to 72 hours following unprotected sex. Progestin-only methods are better tolerated and more effective than combination pills, with pregnancy rates of 1.1% and 3.2%, respectively (78). Emergency contraception is ineffective at disrupting an already established pregnancy.
Method Use
Currently available methods of emergency contraception include COC pills or the copper IUD. There are many
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possible combinations of oral contraceptives that have been shown to be effective. Plan B, a progestin-only dedicated product contains two tablets of 0.75 mg levonorgestrel. Product labeling instructs that the first dose is taken within 72 hours (earlier administration increases effectiveness), and then repeated (second dose) 12 hours later. However, a large randomized trial shows that a single dose of 1.5 mg is as effective as two separate doses of 0.75 mg (79). Additionally, emergency oral contraception has been shown to have efficacy up to 120 hours after intercourse, although the efficacy is reduced the longer the time delay (79). Neither a pelvic examination nor blood pressure measurement (asymptomatic women) is necessary before providing the method. The IUD can be inserted up to 5 days after unprotected intercourse.
Pregnancy testing is unnecessary before emergency contraception unless there is information to suggest that conception already occurred in a previous cycle. A woman should return for pregnancy testing if she does not get her menses within 3 to 4 weeks after taking emergency contraception. Women given emergency contraception should also receive counseling to help them choose an appropriate method for ongoing contraception.
Contraception in Special Circumstances
During the time leading up to the menopause, a woman's concern regarding unplanned pregnancy is heightened by abnormal menstrual cycles and episodes of amenorrhea. Although fertility declines with age, missing a period is disturbing to a woman in the perimenopause unless a very reliable method of contraception is being used. Some methods are particularly advantageous to women in the perimenopause.
The postpartum woman needs help in getting back on a contraceptive program, and usually her obstetrician has given her advice in this regard. Also, the woman wishing to use an IUD needs to wait for involution of the uterus—which usually occurs 4 to 6 weeks after delivery—and therefore is at risk for pregnancy until the IUD is inserted. The physiology of the female reproductive cycle, important to an understanding of the many contraceptive methods, is discussed in Chapter 101.
Diagnosing Pregnancy
Human chorionic gonadotropin (hCG) is a glycoprotein hormone that is produced by the blastocyst and the placenta. Its secretion begins very early and can be detected in the maternal blood as early as 6 days after fertilization. Its concentration in serum approximately doubles every 48 hours during the first 10 weeks of a normal pregnancy. In the past, a number of conditions could give rise to a false positive result, such as the presence of foreign protein or cross-reaction with the luteinizing hormone (LH), follicle-stimulating hormone (FSH), and thyroid-stimulating hormone (TSH). The α-subunit for hCG is common to all of these hormones. However, the β-subunit for hCG is unique, and the currently available pregnancy tests that use the monoclonal antibody methodology test only for the β-subunit. A false-positive reaction, even with home pregnancy detection kits, is extremely rare. There are four major types of pregnancy tests, each with its own characteristics; all are very accurate. The Icon, an enzyme-linked immunoassay, is the most commonly used test because of its simplicity, accuracy, and availability. Any clinician who may be asked to diagnose pregnancy should have a rapid pregnancy diagnosing kit in the office. There is no clinical situation in which one of these tests has a distinct advantage over another.
Radioimmunoassay
The radioimmunoassays are performed on serum samples. Tests include Chorion Quant, Beta Tec, and HCG Beta III. Their features are as follows:
Enzyme-Linked Immunoassay
The enzyme-linked immunoassay tests (Icon, Confidot, Quest) are performed on urine or serum. Their features are as follows:
Radioreceptor Assay
The radioreceptor assay pregnancy test (Biocept-G) is performed on serum. It has the following features:
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Immunoassay
The immunoassays (Neocept, Pregnosis) are performed on urine or serum. Their features are as follows:
The biological half-life of hCG is approximately 1.5 days. The serum hCG result becomes negative approximately 9 to 13 days after spontaneous abortion, if all trophoblastic tissue is expelled (80). The hCG test may remain positive for weeks to months if small foci of functioning trophoblastic tissue remain. This could be seen after incomplete abortion, persistent hydatidiform mole, or choriocarcinoma.
Unplanned Pregnancy
All contraceptive methods are associated with some failures, which may result in an unplanned pregnancy. Women with such a pregnancy are faced with the difficult decision of whether to carry or to terminate the pregnancy. Estimates are that almost 50% of the approximately 4 million births in the United States in 1992 were unplanned.
Currently, about 1.5 million therapeutic abortions are performed each year in the United States. The usual method of early termination of pregnancy in the United States is a surgical suction dilation and curettage performed in an outpatient center, free-standing clinic, or obstetrician's office, usually with the patient under local anesthesia. The antiprogesterone compound, mifepristone, was approved in 2000 for use in conjunction with misoprostol for the medical termination of early pregnancy. The current FDA-approved regimen provides 600 mg of mifepristone orally on day 1, followed on day 3 by 400 µg of misoprostol given orally in the provider's office.
Preconception Care
A variety of medical conditions, occupational situations, and social practices have consequences on early pregnancy. Because organogenesis begins about 17 days after conception, whereas traditional prenatal care may not commence for several weeks thereafter, there is ample reason to provide preconception care in an effort to optimize a woman's medical, social, and emotional readiness for pregnancy.
Preconception care should include a thorough history, a targeted physical examination, focused laboratory investigations, and specified counseling. The couple should be interviewed regarding family and genetic history, with appropriate carrier screening for inheritable conditions such as hemoglobinopathies, Tay-Sachs disease, or cystic fibrosis, among others. Existing medical conditions should be reviewed and medical therapy optimized, especially for patients with diabetes mellitus or hypertension. Women should discontinue, or be offered alternatives to, drugs known to be contraindicated in pregnancy, such as isotretinoin or Coumadin. Infectious disease risks should be assessed (e.g., rubella, hepatitis B, HIV), and, if appropriate, vaccines should be offered for rubella varicella, and hepatitis B. Additionally, screening should be offered for sexually transmitted diseases such as chlamydia, gonorrhea, and syphilis. Nutrition and eating habits should be evaluated. Although a multivitamin may be suggested, megavitamin supplementation should be avoided. Evidence suggests that daily intake of 0.4 mg of folic acid before conception significantly reduces the risk of neural tube defects.
Finally, a review of a couple's social readiness for pregnancy can help them focus on the upcoming responsibilities of pregnancy and childcare. Social habits of smoking and alcohol intake should be curtailed, and providers should take the opportunity to motivate substance abusers to seek counseling. Patients should consider domestic and economic readiness for pregnancy, and they should know their employer's policy regarding leave benefits for complicated and uncomplicated pregnancies (81).
Specific References*
For annotated General References and resources related to this chapter, visit http://www.hopkinsbayview.org/PAMreferences.
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