Hacker & Moore's Essentials of Obstetrics and Gynecology: With STUDENT CONSULT Online Access,5th ed.

Chapter 26

Family Planning

REVERSIBLE CONTRACEPTION, STERILIZATION, AND ABORTION

Anita L. Nelson

Family planning plays a critical role in promoting the personal health of women, and it uniquely optimizes both maternal health and fetal well-being by allowing couples to plan and prepare for the pregnancies they desire. As such, family planning also has major public health implications.

Condoms and oral contraceptives (OCs) were recognized by the U.S. Centers for Disease Control and Prevention (CDC) as among the 10 most important public health inventions of the 20th century. Considering that this was the century in which vaccinations and treatments for smallpox, polio, yellow fever, and many other diseases that had plagued humans for eons were developed, such recognition highlights the magnitude of the contributions these birth control methods have made. Every year, 600,000 women die worldwide from pregnancy and pregnancy-related causes, and another 3 million women suffer significant permanent disabilities.

Many contraceptive methods also help reduce the spread of some sexually transmitted infections (STIs). For example, even though only 13% of married African women use effective barrier methods of contraception, it has been estimated that, in 2002, those birth control methods prevented 173,000 cases of human immunodeficiency virus (HIV) infection in sub-Saharan Africa.

As effective as modern contraceptives have been, they have not yet achieved their full potential. Nearly half of pregnancies in the United States are classified as “unintended,” meaning that the woman electively aborts the pregnancy, or continues with a pregnancy that she did not plan. Many unintended pregnancies occur in women who are using contraception but are not using their chosen method correctly. Nearly 1 million pregnancies occur every year in women taking OCs. More than half of OC users miss three or more pills each cycle, and many do not refill their prescriptions on a timely basis. Pregnancies that are categorized as “intended” include planned and prepared pregnancies as well as pregnancies to which women are indifferent.

When birth control methods in sexually active women are grouped into tiers based on their efficacy with typical use (Table 26-1), it becomes obvious that the most efficient methods are those that are long-term, convenient, and do not require any ongoing action from the woman (Tier 1). For example, the intrauterine devices (IUDs) and progestin implants provide the highest level of pregnancy protection, with first-year failure rates in typical use of less than 1% (Table 26-2). Other hormonal methods, such as the once-every-3-months injection, monthly vaginal rings, weekly patches, and daily pills are in tier 2. Each of these hormonal methods has the potential for very low pregnancy rates (1%), but in typical use, they have first-year failure rates of 7% to 8%. Tier 3 contraceptive methods are the barrier and behavioral methods. Here the differential between the potential that the method offers and what is really seen is widest. For example, male condoms have a less than 2% failure rate if used correctly and consistently with every episode of intercourse. However, in real life, the pregnancy rate is 17.4%. Female barrier methods (diaphragms, cervical caps, shields, and female condoms) have higher pregnancy rates. Interestingly, behavioral methods such as coitus interruptus and fertility awareness methods have rates that are almost equivalent to many barrier methods in typical use.

TABLE 26-1 TIERS OF EFFICACY

Tier

Method of Contraception

1: Longer term

Progestin implants and intrauterine devices

2: Combined hormonal

Depot medroxyprogesterone acetate injections

Vaginal rings, transdermal patches

Oral contraceptive pills

3: Barrier and behavioral

Male condoms, diaphragms

Caps, female condoms, shield

Spermicides

Withdrawal, fertility awareness method, natural family planning

TABLE 26-2 CONTRACEPTIVE FAILURE RATES COMPARING TYPICAL USE AND PERFECT USE

Contraceptive Method

Percent Failure within First Year of Use

Perfect Use

Typical Use

No method

85

85

Male sterilization

0.10

0.15

Female sterilization

0.5

0.5

Copper ParaGard T 380A IUD

0.6

0.8

Levonorgestrel-releasing IUD

0.1

0.1

DMPA

0.3

6.7

OC—combined

0.3

8.7

OC—progestin only

0.5

8.7

Diaphragm with spermicide

6

16

Condom—male, latex

2

17.4

Cervical cap—parous

26

32

Cervical cap—nulliparous

9

16

Spermicides

15

29

Fertility awareness

19

25.3

Withdrawal

18.4

DMPA, depot medroxyprogesterone acetate; OC, oral contraceptive.

1. Kost K, Singh S, Vaughan B, Trussell J, Bankole A. Estimates of contraceptive failure from the 2002 National Survey of Family Growth. Contraception. 2008;77(1):10–21

2. Hatcher RA, Trussell J, Nelson AL, Cates W Jr, Stewart FH, Kowal D. Contraceptive Technology, 19th ed. NewYork, Ardent Media, Inc. 2007.

The mechanisms of action vary among method of family planning. Contrary to prevailing opinion, the primary action of virtually all methods of birth control is contraception (the prevention of fertilization). Abortion is the disruption of an established pregnancy. Interception is defined as an action that blocks implantation (i.e., one that works after fertilization but before pregnancy is established 7 days later).

The safety of all methods of family planning is well established. In selecting options for an individual woman, the requirement is that any method offered must be safer to the woman’s health than pregnancy. It is from that perspective that the World Health Organization (WHO) has developed its Medical Eligibility Criteria (MEC; Table 26-3), which rates the appropriateness of each major contraceptive method in a variety of medical circumstances. Recommendations are made on a 1 to 4 scale, in which a rating of 1 indicates approval and 4 represents an absolute contraindication. This rating often differs from the labeling for individual products, which generally reflects theoretical concerns and desires by the manufacturers to protect themselves from product liability. Prescribers should act on evidence-based recommendations such as the WHO MEC.

TABLE 26-3 WORLD HEALTH ORGANIZATION MEDICAL ELIGIBILITY FOR INITIATING CONTRACEPTION: ABSOLUTE AND RELATIVE CONTRAINDICATIONS

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image Contraception

TIER 1 CONTRACEPTIVE OPTIONS

Intrauterine contraceptives and implants are the most effective, reversible methods available to women at risk for pregnancy. Typical failure rates closely correspond to those seen with correct use (see Table 26-2). Each is also very safe and can be used by women with serious medical conditions for whom pregnancy may be very dangerous.

Contraceptive Implants

In the United States, only one implant is currently available—a single-rod system called Implanon. The contraceptive rod measures 4 cm in length and 2 mm in diameter. The progestin, etonogestrel, is mixed into the matrix of the plastic rod. The rate at which etonogestrel is released is controlled by a releasing membrane that surrounds the rod. This rod is indicated for up to 3 years of use. In clinical trials around the world, involving the experience of more than 58,000 women-cycles, not a single woman became pregnant when the rod was in place. Because some women conceived within 2 weeks of removal, those pregnancies are included as possible method failures, bringing the first-year failure rate in the United States to 0.38%.

The implant is placed in the subcutaneous tissue of the inner aspect of a woman’s upper nondominant arm. Placement is done in the office in a 1-minute procedure. Virtually every woman is a candidate for this convenient, rapidly reversible method. Only women who have had breast cancer within the last 5 years have an absolute contraindication to use of the contraceptive rod. Women who use anticonvulsants, such as phenobarbital or dilantin, which increase cytochrome P-450 enzyme activity, will have higher failure rates, as will women using nonprescription therapies, such as St. John’s Wort.

The contraceptive rod was designed to release etonogestrel at levels adequate to suppress ovulation. With detailed ultrasonic and laboratory testing, it was demonstrated that no woman with the rod ovulated during the first 30 months of use, and during the last 6 months of use, only three ovulations occurred. Pregnancy was prevented in the latter cases presumably because the thickened cervical mucus blocked sperm entry into the upper genital tract. The progestin released also affects the endometrium. These endometrial changes do not contribute in any meaningful way to pregnancy protection but do alter bleeding patterns, which become “unpredictably unpredictable.” Women can alternate among amenorrhea, oligomenorrhea, and regular menses. Women should be advised to carry light-day panty liners to be prepared for the unscheduled bleeding and spotting. Return to fertility is rapid after removal of the implant. Removal may be accomplished as an office procedure in less than 3 minutes.

Other contraceptive implants are available outside the United States. The original Norplant-6, with six capsules filled with levonorgestrel powder, and the Jadelle 2 implant system each provide almost equivalent pregnancy protection for up to 5 years.

Intrauterine Contraceptives

There are two intrauterine contraceptives available in the United States: the copper T 380A intrauterine device (Copper-T-IUD) and the levonorgestrel-releasing intrauterine system (LNG-IUS). They both offer pregnancy protection equivalent to sterilization and should be seriously considered as an alternative in any woman considering that procedure.

The Copper T-380A IUD (Figure 26-1) is approved by the U.S. Food and Drug Administration for 10 years of use, but studies show it remains very effective for at least 20 years. This IUD provides excellent pregnancy protection that is convenient and rapidly reversible. First-year failure rates are 0.7%, and cumulative 10- to 12-year pregnancy rates are 1.4% to 1.9%. Most women are candidates for IUD use, including those with serious medical problems such as hypertension, morbid obesity, diabetes, stroke, myocardial infarction, and cancer. The only absolute contraindications to immediate IUD placement are active infection or cancer in the cervix or uterus, distortion of the uterine cavity, or a uterine cavity that is not the correct size (6 to 9 cm in depth) to accommodate the device.

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FIGURE 26-1 Copper T 380A intrauterine device.

The copper IUD works as a contraceptive by immobilizing and killing sperm. Women using this IUD should check their tail strings monthly to verify that their device is still in place. They should be advised that their menses may be heavier and longer.

For women who have heavy or painful menses, the LNG-IUS is generally a better choice. This system is effective for at least 5 years. With first-year failure rates of 0.14%, the LNG-IUS prevents conception by thickening the cervical mucus to prevent sperm entry into the upper genital tract. Over time, the high doses of progestin profoundly change the endometrium, which is reflected in the user’s bleeding patterns. Women generally experience frequent episodes of unscheduled bleeding and spotting in the early months, following which bleeding becomes rare. By 12 months, 20% of women have no bleeding or spotting, and the most common pattern seen is 1 to 3 days of spotting a month. Hence, hemoglobin levels rise.

In virtually every country, the LNG-IUS is approved for both contraception and for treatment of heavy, prolonged vaginal bleeding. It is at least as effective as endometrial ablation in this regard.

TIER 2 CONTRACEPTIVES: COMBINED HORMONAL PRODUCTS AND PROGESTIN-ONLY INJECTIONS AND PILLS

All these methods work primarily by thickening cervical mucus and by blocking the luteinizing hormone surge to prevent ovulation. Each of these hormonal methods has about the same failure rate in typical use (8%), and each has the potential for much higher efficacy if used correctly and consistently (0.3% to 2%).

Barriers to successful use must be removed to help women achieve more success with these methods. Quick-start protocols should be followed to allow women immediate access to protection. Any of these methods can be started any day of a woman’s cycle as long as she is not pregnant, uses emergency contraception (EC) if she had unprotected intercourse in the prior 5 days, and uses condoms for 7 to 9 days afterward until her hormonal method can reliably protect her. Routine provision of EC in advance of need provides backup for inevitable lapses in ongoing contraceptive use.

Combined Hormonal Products

Combined hormonal contraceptives with synthetic estrogens and progestins are available as once-daily pills, once-a-week transdermal patches, and once-a-month vaginal rings. Combined oral contraceptives are available with different progestins and varying doses of estrogen to enable clinicians to find formulations that will work well for different women. Formulations are available for extended cycle use to eliminate or minimize the number of scheduled bleeding episodes induced by placebo pills. This scheduled bleeding is not medically indicated but may be desired by some women for personal reasons.

Many other health benefits accrue to women who use combined hormonal contraceptives. Three formulations are approved for the treatment of acne, and one is approved for treatment of premenstrual dysphoric disorder. Bleeding episodes with hormonal methods are less heavy, shorter, less painful, and more predictable than spontaneous menses. The risk for ovarian and endometrial cancer is reduced, and these health benefits increase the longer a woman uses the hormonal contraception.

For healthy reproductive-aged women, combined hormonal contraceptives are very safe. The only measurable risk is the slightly increased incidence of venous thromboembolism (VTE)—deep venous thrombosis and pulmonary embolism. This risk is overshadowed by the risk for VTE during pregnancy. Benign hepatic tumors are an extremely rare problem, and symptomatic cholelithiasis and mild hypertension may be slightly increased. Modern lower-dose hormonal contraceptives do not increase the risk for breast cancer, cholelithiasis, fibroids, or heart attacks in healthy women. Women with preexisting medical problems such as hypertension or diabetes and older women who smoke or are obese face higher risks and require individualized recommendations. The WHO MEC in Table 26-3provides guidance.

Certain medical conditions are absolute contraindications to the use of combined hormonal methods because their use presents more risks than would pregnancy. These include a history of heart attack, stroke, breast cancer, labile hypertension, advanced diabetes, hepatic failure, migraine with aura, or unexplained abnormal uterine bleeding.

Although most patients believe that combined hormonal contraceptives have numerous side effects, the incidence of “hormonally related” side effects is not increased in placebo-controlled trials. The only exception is the risk for melasma. There are transient changes that do occur in the first 3 months, including unscheduled bleeding or spotting and breast tenderness. There are also women who are more sensitive to certain compounds, but the availability of a wide range of products and delivery systems helps tailor the method to the needs of the individual woman.

Progestin-Only Pills and Injections

Progestin-only methods can be used by virtually every woman, with the exception of women who have had breast cancer in the past 5 years. Women using drugs that increase cytochrome P-450 are not good candidates for progestin-only pills (POPs) but are still candidates for depot medroxyprogesterone acetate (DMPA) injections. Each of these progestin-only methods thickens cervical mucus, but DMPA also profoundly suppresses gonadotropins to inhibit ovulation.

POPs are immediately reversible. Return to ovulation with DMPA takes a median time of 10 months. With POPs, women usually continue to experience their own cycles but have less blood loss. With DMPA, there is initially a significant amount of unscheduled bleeding, but with time, most women achieve amenorrhea. Some women gain weight using DMPA. The noncontraceptive benefits with DMPA are impressive, including a reduced incidence of menorrhagia, dysmenorrhea, pain from endometriosis, endometrial cancer, and acute sickle cell crises.

TIER 3 CONTRACEPTIVES: BARRIER AND BEHAVIORAL METHODS

The advantage of this tier of contraceptives is that they need to be used only at the time of intercourse, which is also the feature that most profoundly decreases their utilization and increases their failure rates in typical use.

Barrier Methods

When used correctly and consistently, male condoms have a failure rate of 2%, but in typical use, they are only slightly more effective than withdrawal (17.4%). Latex condoms also have great potential to reduce all sexually transmitted infections, but with episodic use, this protection is compromised. To encourage the use of latex condoms, they are now available in a range of different sizes (from snug fitting to roomier from base to head) and different shapes. An array of features has been added to appeal to users, including different textures, flavors, and scents. They also come with a wide variety of accessories, including freshening wipes and vibrating rings to reward condom use.

For couples with latex allergies or women using petroleum-based vaginal products, polyurethane condoms are available. The polyurethane transmits body heat and is impermeable to viruses and bacteria. Animal cecum condoms are not recommended. Condom use should always be advised to minimize STI risk in combination with other methods, but spermicidal lubricated latex condoms offer no additional protection against STIs or pregnancy.

Female barrier methods include diaphragms, a vaginal shield, a cervical cap (Femcap), and female polyurethane condoms; vaginal spermicides are also included in this category. Each of the female barriers works best if used with spermicidal gel. Male latex condoms can be combined with all female barrier methods except the female condom. With cleansing, the diaphragm, shield, and cap are reusable for up to 1 year. Spermicides are available as immediately active foams gels and sponges (after hydration) and delayed-acting suppositories and films. Spermicide use is not recommended for multiple applications in a 24-hour period because multiple uses may increase the transmission of HIV.

Behavioral Methods

Withdrawal or coitus interruptus is the most effective behavioral method. The male superior coital position allows the man to move his penis away from the woman’s genitals before ejaculation.

For recently breastfeeding women, lactational amenorrhea is very effective. When women exclusively breastfeed on demand and have no menses for the first 6 months postpartum, the failure rate is 2%. After 6 months, it is prudent to add another method.

Fertility awareness methods employ a variety of techniques to detect at-risk days. Once those days are identified, couples can practice periodic abstinence or use another behavioral or barrier method at that time. The historical “rhythm method” has been replaced by other methods of natural family planning including the standard days method with its Cycle Beads, urine testing (for luteinizing hormone and estrogens that predict ovulation), sophisticated computing machines, and the Billings technique for detecting cervical secretions on the introitus that change before ovulation.

Other sexual practices that couples use to avoid genital contact to reduce pregnancy may include “outercourse,” oral-genital pleasuring, mutual masturbation, or rectal intercourse. These practices may not reduce the risk for STIs.

Emergency Contraception

EC pills containing levonorgestrel or norgestrel are intended to be a backup method for use after unprotected intercourse. It is one of the most important innovations in contraception. In the United States, availability is limited to people aged 18 years and older.

Virtually every woman can use the levonorgestrel EC (marketed as Plan B). Product labeling advises that the two doses be taken 12 hours apart, but a single dose of two pills is at least as effective. Use within 72 hours of exposure is advisable, so clinicians should provide women at risk for unscheduled intercourse with a prescription in advance. EC is not an abortifacient, and it has no teratogenic effect if inadvertently administered during pregnancy. It works only by suppressing ovulation. Various combinations of routine OCs with levonorgestrel or norgestrel plus estrogen can be offered if LNG-EC is not available.

image Sterilization

Permanent sterilization is the most common method of birth control used by U.S. women older than 30 years. Common methods of fallopian tube sterilization are listed and described in Table 26-4.

TABLE 26-4 METHODS OF TUBAL STERILIZATION

Surgical Approach

Technique

Surgical Procedure

Laparotomy

Pomeroy

Ligature around a “knuckle” (or loop) of tube; excision distally

 

Madlener

Crushing and ligature of loop of tube

 

Irving

Double ligation, excision between; proximal end buried in myometrium; distal end buried in broad ligament

 

Uchida

Tubal serosa stripped from muscular coat; tubal segment excised; proximal end ligated and buried in broad ligament

 

Fimbriectomy

Ligation of distal end of tube and mesosalpinx; excision of fimbriated end

Laparoscopy

Electrocoagulation

Electrical “burn” of two adjacent segments with or without transection

 

Falope ring

Loop of tube drawn into applicator tube; plastic ring placed around both limbs of loop

 

Hulka clip

Plastic crushing clip placed across tube (not a loop); kept closed by steel spring

 

Filshie clip

Titanium clip placed across the tube; associated with increased risk for infection

Minilaparotomy

Pomeroy ligation; electrocoagulation

As above

Transcervical

Insertion of tubal plug

Placement of plug through a hysteroscopic transcervical approach that causes fibrosis over time

Vasectomy (interruption of the vas deferens) can be done under local anesthesia in an office setting (“no scalpel” vasectomy) or as an outpatient surgical procedure. Interestingly, there are no data available about long-term efficacy of vasectomy. Once a man has achieved azoospermia following 6 to 10 ejaculations after the procedure, he is considered sterile. There are no long-term hormonal, metabolic, or autoimmune effects associated with vasectomy.

Fallopian tube procedures are most commonly used for female sterilization, although hysterectomy performed for other indications also sterilizes a woman. Tubal interruption can be done through a mini-laparotomy incision, using a laparoscope or hysteroscopically. Usually, mini-laparotomy techniques with suture ligation and interruption of the tube (the Pomeroy techniqueFigure 26-2are performed through a small subumbilical incision immediately postpartumLaparoscopic approaches are usually performed as interval procedures in nonpregnant women when the woman’s uterus lies in the pelvis. The fallopian tubes can be interrupted with cautery, clips, or rings (Figure 26-3). With the hysteroscope, small plugs can be anchored in the proximal portions of the tube to incite fibrosis and, over time, cause the tube to occlude.

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FIGURE 26-2 Pomeroy method of tubal ligation. A: Tube is grasped with Babcock forceps. B: A loop is ligated. C: The loop is excised. D: Several months later, the fibrosed ends of the tube separate.

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FIGURE 26-3 Tubal occlusion with the Hulka clip (A) and Falope ring (B). The ring causes a portion of tube to undergo necrosis, and the end result resembles the illustrated tube in Figure 26-2D. Cautery procedures use electric energy to acutely destroy portions of each fallopian tube.

Reversibility of sterilization procedures varies by technique and by the amount of fallopian tube destroyed by the initial procedure. The range of success varies from 30% to 70%. The convenience of tubal ligation is obvious, but the cost and the surgical and anesthetic risks (e.g., hemorrhage, infection, damage to intraperitoneal structures, and even death) need to be considered.

Ten-year follow-up studies demonstrate that all sterilization methods are less effective in younger women (up to 5.4% failure rates in women younger than 28 years), but that postpartum sterilization procedures have the lowest 10-year failure rates.

Long-term complication rates are low. However, because at least 6% to 10% of women consider reversal and many more regret having been sterilized, it is critical to encourage women to consider all their reversible options first.

image Abortion

Abortion is the interruption (spontaneous or induced) of an established pregnancy before 20 weeks’ gestation. The term miscarriage is usually used by the lay public to describe spontaneous pregnancy loss. Elective and therapeutic abortion are terms used to describe induced pregnancy termination.

Under the 1963 Roe v. Wade U.S. Supreme Court decision, induced abortion is a legal procedure until fetal “viability” is achieved, usually described as 24 weeks of gestational age, unless a fetal anomaly inconsistent with extrauterine life is identified to permit later pregnancy termination. Maternal mortality rates decrease significantly whenever abortion is legalized and provided by medically trained personnel. Every pregnant woman needs to be made aware of all her options, including continuing the pregnancy, abortion, and adoption. Decisions in these areas are extremely difficult and personal. In some states, women are required to wait 24 hours between giving consent and undergoing the termination. In some states, a teen’s parental notification or approval is required before abortion. Access to abortion services may become increasingly difficult because more than half of the counties in the U.S. have no abortion providers.

Early in pregnancy (less than 49 days), both medical and surgical procedures can be offered. Mifepristone (an antiprogestin) can be administered and followed later by misoprostol (a prostaglandin) to induce uterine contractions expelling the products of conception. This approach has been proved effective (96%). Other agents, such as methotrexate, can be used to induce abortion, but methotrexate is less effective and generally requires a longer time to complete the process.

Aspiration with a manual vacuum or suction curettage is more than 99% effective in early pregnancy after cervical dilation has been achieved with misoprostol or laminaria (Figure 26-4). This type of procedure can be performed either under local anesthesia (paracervical block) or under sedation with the patient awake. Complication rates are very low, but the patient must understand that hemorrhage, infection, uterine perforation, retained products of conception, and anesthetic complications are possible. Early pregnancy termination is safer than continuing the pregnancy or undergoing tonsillectomy. There are no long-term adverse effects on women’s reproductive health with uncomplicated procedures.

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FIGURE 26-4 Laminaria tents (osmotic dilators) used to gradually dilate the uterine cervix by absorbing body fluid.

Second-trimester abortions are generally performed because prenatal diagnosis has revealed a serious genetic abnormality or because of an intrauterine fetal demise. Here, the role of medical abortion has been pivotal. Prostaglandin or misoprostol intravaginal suppositories are used to induce contractions, and the fetus is delivered vaginally. Occasionally, follow-up curettage may be needed to remove an undelivered placenta. Some patients prefer surgical procedures such as dilation and evacuation for elective termination. This surgical procedure may be needed to treat women with infected pregnancies (septic abortions).

Although early abortion is an extremely safe procedure from a maternal safety perspective, most experts and patients would agree that pregnancy prevention is clearly preferable.

SUGGESTED READING

Abbott J. Transcervical sterilization. Curr Opin Obstet Gynecol. 2007;19:325-330.

Hatcher R.A., Trussell J., Nelson A.L., et al. Contraceptive Technology, 19th ed. New York: Ardent Media; 2007.

Hatcher R.A., Zieman M., Cwiak C. A Pocket Guide to Managing Contraception. Tiger, GA: Bridging the Gap Foundation; 2005.

Speroff L., Darney P.D. A Clinical Guide for Contraception, 4th ed. Baltimore, MD: Lippincott Williams & Wilkins; 2005.