Unintended pregnancy is a major womenâ€™s health problem. In the United States, there are 62 million women of child bearing age (aged 15 to 44 years) and approximately 62% of them use a contraceptive method, and yet as many as 50% of all pregnancies are unplanned. The consequences of such unscheduled pregnancies include delayed prenatal care; early pregnancy exposure to smoking, drinking, or substance abuse; low birth weight; and decreased chances of breastfeeding after delivery. These risks exist despite a plethora of safe, effective and readily available methods of contraception. This article covers female contraceptive methods, including sterilization, and emergency contraception.
More than 99% of sexually active women have used at least 1 contraceptive method at some time. The choice of contraceptive method is determined by the womanâ€™s individual risk factors, age, frequency of sexual activity, number of sexual partners, permanence, and efficacy (Table 1).
Specific screening before prescribing contraceptives is not mandatory. After the initial visit, a 3-month follow-up is suggested for counseling and reinforcement, and then yearly visits thereafter. Women should be counseled about the efficacy, side effects, and correct methods of use; about the signs and symptoms that require return to the physician; and about protection against sexually transmitted diseases (STDs).
Table 1: Effectiveness of Contraceptive Methods
|Pregnancies per 100 Women in First 12 Months of Use|
|Contraceptive Method||As Commonly Used||Perfect Use|
|Combined oral contraceptives||9||0.3|
|Depot medroxyprogesterone acetate||6||0.2|
|Lactation amenorrhea method||2||0.5|
|Diaphragm with spermicide||12||6|
Adapted with permission from Contraception (Trussell J. Contraceptive failure in the United States. Contraception 2011; 83:397-404). Copyright Â© 2011, with permission from Elsevier. http://www.sciencedirect.com/science/journal/00107824.
Mechanism of action of hormonal contraceptives
Hormonal contraceptives contain either an estrogenic agent and a progestogen together in a delivery system or a progestogenic agent alone. The mechanism of action of these agents is complex. Follicular development and ovulation are prevented by suppression of follicular stimulating hormone (FSH) and luteinizing hormone (LH). The other major contraceptive effect is a change in cervical mucus, causing the production of thick cervical mucus that impairs sperm migration into the cervix. Progesterone-only pills inhibit ovulation in only 60% of patients, thus the predominant contraceptive effect is achieved by cervical mucus preventing sperm penetration. While endometrial thinning does occur, there is no evidence that prevention of implantation is a contraceptive effect and these agents do not act as abortifacients.
On June 10, 1957, the FDA approved the first oral contraceptive, the drug Enovid 10. Composed of 9.85 mg of norethynodrel and 150 mcg of mestranol, it contained 3 times the dosage of steroids that are in modern oral contraceptives. Lower doses have been found to be equally effective and to cause fewer side effects, such as headache, breast tenderness, nausea, and hypertension. In particular, lower doses of ethinyl estradiol are associated with a lower risk of thrombosis. Mestranol is no longer used in oral contraceptives available in the US nor is the progestin ethynodrel. Today, combination pills contain < 50 mcg of ethinyl estradiol, and most contain 30 mcg or 35 mcg, and the newer ones contain 20 mcg, 25 mcg, or even 10 mcg.
Modern contraceptives contain a combination of estrogen and a progestogen of varying types and dosages. The progesterones are classified by generation, indicating when they were introduced. First-generation progestogens are norethisterone (NET), ethynodiol diacetate, and lynestrenol (LYN), which are no longer used, and norethindrone (NE). Second-generation progestogens, introduced in the 1970s, are norgestrel and levonorgestrel. Third-generation progestogens, added in the 1980s are, desogestrel (DSG), gestodene (GSD), and norgestimate (NGM).
The fourth-generation of progestin, drospirenone, differs from the others because it is derived from 17a-spirolactone, not from the 19-nortestosterone derivatives. Drospirenone is a spironolactone analogue with antiandrogenic and antimineralocorticoid properties. The antimineralocorticoid effect of drospirenone reduces water retention and bloating. These agents should not be used in women with hepatic failure, renal insufficiency, or adrenal insufficiency. Women taking nonsteroidal anti-inflammatory agents (NSAIDs), potassium-sparing diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin II receptor antagonists, or potassium supplements should have serum potassium levels checked during the first treatment cycle.
Dienogest is the newest type of progestogen and has agonistic/antagonistic activity on the human progesterone receptor (PR), androgen receptor (AR), glucocorticoid receptor (GR), mineralocorticoid receptor (MR), estrogen receptor alpha (ERalpha), and estrogen receptor beta (ERbeta). It is available only in combination with the first new estrogen, estradiol valerate (a synthetic estrogen that is converted to estradiol in a woman's body), marketed as Natazia.
Combined hormonal contraceptive pills are also classified as monophasic, biphasic, tri-phasic, or quadraphasic pills. The classification depends on the way that the progestogen dose is increased throughout the cycle. Monophasic pills have the same dose of estrogen and progestogen in all active pills. The other phasic pills have different concentrations of estrogen and progestogen varying throughout the pack. The concentration can vary from brand to brand. In some newer regimens, the patient takes placebo pills for fewer days per month than with older regimens, or the placebo pills have been replaced by low-dose hormone pills. These regimens reduce the number of days of withdrawal bleeding, with the intent of improving contraceptive effectiveness and patient adherence, and reducing side effects.
There are also formulations specifically designed to create longer cycles. Levonorgestrel/ethinyl estradiol (Seasonale/Quasense/Jolessa) is a 91-day oral contraceptive regimen that contains levonorgestrel (progestin) and ethinyl estradiol for 12 weeks (84 days), followed by 1 week of placebo. Women using this method have only 4 menses per year. Seasonique contains the same formulation as Seasonale but with the addition of ethinyl estradiol in a lower dose during the 13th week, without levonorgestrel. This addition may reduce the hormonal withdrawal symptoms such as menstrual migraine and dysmenorrhea that can occur during the placebo week with long-cycle hormonal contraceptives. It should be noted that women who use continuous long-cycle hormonal contraception tend to have more unscheduled bleeding than do women who use shorter-cycle regimens.
Ethinyl estradiol/levonorgestrel (Lybrel) is taken in a continuous, noncyclic, 365-day regimen. There is no hormone-free period with this regimen. Therefore, hormone levels remain constant, ovulation is suppressed, and women have no menstrual bleeding. Many women achieve the same effect by taking traditional monophasic combined oral contraceptive pills in a similar off-label manner, that is, they take the active pills and throw away the placebo pills. This continuous method has the highest rate of unscheduled bleeding.
There are other minor variations as well. For example, Femcon Fe, contains the same active ingredients as Ovcon 35. However, Ovcon 35 must be swallowed, whereas Femcon Fe is a spearmint-flavored, chewable tablet with the placebo pill containing an iron supplement. The formulations Beyaz and Safyral are the same as Yaz and Yasmin with the addition of levomefolate calcium 0.451 mg in both active and placebo pills. Low folate levels are associated with neural tube defects in pregnancy.
Combined oral contraceptives (COC) are used for contraceptive reasons by 27% of women aged 15 to 44 years in the US. Yet there remain several contraindications for combination hormonal contraceptives. The estrogen component increases hepatic production of factor VII and X as well as fibrinogen. Therefore, the risk of thromboembolic phenomena is increased. These drugs should not be used in women who have had a thromboembolic event or stroke or who have a familial hypercoagulation disorder. In addition, COCs should not be used in women with liver disease, a history of estrogen-dependent tumor, undiagnosed abnormal uterine bleeding, hypertriglyceridemia, and smoking in women aged > 35 years. Patients at risk for hypertension should undergo screening before initiating contraception. If a patient is aged < 35 years, does not smoke, and her blood pressure is well controlled, COCs are a reasonable choice.
The estrogen component of COCs causes an increase in high-density lipoprotein (HDL) levels and a decrease in low-density lipoprotein (LDL) levels. This is offset by the increase in triglycerides. Women with dyslipidemia who have other risk factors for cardiovascular disease should consider alternative contraceptive methods.
A diagnosis of migraine is another important consideration. Because some women experience an exacerbation of headaches during menses, continuous oral contraceptives can mitigate this phenomenon. Most studies have shown a higher risk of stroke in women who have migraine with aura. Those without aura do not have this increased risk. Because of this increased risk and the devastating impact of a stroke, most clinicians recommend the use of a progestin-only agent in women with migraine with aura.
The data surrounding association of COCs are somewhat confusing. Oral contraceptives have been noted to cause a small increased risk of breast cancer in current users. This very small risk was not seen in women who had discontinued oral contraceptive use 10 or more years earlier. Low-dose oral contraceptive use has not been shown to be linked to an increased risk for breast cancer in women who carry the BRCA-1 and BRCA-2 mutations, nor in those with a family history of the mutation. The use of low-dose oral contraceptives reduces both the risk of ovarian cancer and the incidence of benign breast disease compared to non-users.
In an otherwise healthy, nonsmoking woman aged > 35 years, the use of oral contraceptives is safe. Perimenopausal women in particular may benefit from the reduction in irregular bleeding and vasomotor symptoms that accompanies the use of oral contraceptives. Because testing to confirm menopause is not reliable due to hormonal fluctuations, these women may continue using this method until they are aged 50-55 years, with annual assessment of risks and benefits.
The use of combination contraceptives by diabetic women should be limited to those who do not smoke,
are aged < 35 years, and are otherwise healthy. Progesterone-only methods may be more appropriate in women who suffer from migraines with aura, lupus, sickle cell anemia, hypertension, or diabetes with vascular disease. Although the contraindications for usage of progestin only methods are few, but package labeling approved by the FDA often is the same as that for combined estrogen/progestin methods. For example, the package insert for norgestrel progesterone only oral contraceptive and depot medroxyprogesterone list a history of thromboembolism as a contraindication to usage. This contraindication is not supported by the literature.
Side Effects and Precautions
Oral contraceptive pills should be taken at the same time each day, require a prescription, and provide no protection against STDs. Dizziness, mood changes, decreased libido, nausea, spotting, amenorrhea, and breast tenderness are among the most common side effects. Irregular unscheduled bleeding is a common complaint and is the cause of discontinuation in as many as 50% of first-time users. The public perception of weight gain associated with oral contraceptives has not been supported by data in the literature. Various studies have found no significant differences in weight gain between users and non-users. Overall, 60% of combined oral contraceptive users have no side effects and the vast majority of the side effects experienced are minor.
In a 2011 Cochrane review, types of progestogens in low dose combined hormonal contraceptives were compared for their effectiveness and side effects. It was noted that levonorgestrel pills were less likely to be discontinued than were norethisterone containing pills. Gestodene pills caused less bleeding between periods than levonorgestrel containing pills, but the evidence was not conclusive. No other conclusion could be drawn due to insufficient evidence.
Contrary to popular belief, antibiotic usage is not associated with contraceptive failure. Recent studies have shown that the only antibiotic that can decrease the effectiveness of COCs is rifampin, which induces the liver enzymes that metabolize the steroids. There is some evidence that antiretrovirals may also decrease the steroid level. A standard rather than low-dose pill may be more appropriate in these patients.
Some anticonvulsants have been shown to decrease the effectiveness of COCs by the same mechanism. This is seen with phenobarbital, phenytoin, carbamazepine, oxcarbazepine, felbamate, topiramate, and vigabatrin. It is not seen with ethosuximide, gabapentin, lamotrigine, levetiracetam, tiagabine, valproic acid, or zonisamide. It is important to note that while studies have found decreased levels of oral contraceptive steroids, there has not been a documented increase in failure rate. These women should be advised to use a 30 mcg to 35 mcg dosage, although some women may choose to use an additional barrier method. Oral contraceptives do not increase the growth of leiomyomata and can reduce the associated heavy menses.
In July 2011, the Centers for Disease Control (CDC) recommendations were revised for the use of contraceptive methods during the postpartum period in women who are not breast feeding. According to this report, women should avoid the use of combined hormonal contraceptives for the first 21 days following delivery due to the high risk for blood clots during this period. From days 22-42 after delivery, a woman who does not have risk factors for blood clots can start using a combined hormonal contraceptive, but those with risk factorsâ”€a history of blood clots or recent cesarean sectionâ”€should usually avoid this method. By day 43 after delivery, no restriction was placed on the use of a combined hormonal contraceptive. Recommendations were not changed for women who are breast feeding.
Noncontraceptive Benefits of Oral Contraceptives
Oral contraceptives have been successfully used in the treatment of hyperandrogenism, including idiopathic hirsutism and polycystic ovary syndrome. Levonorgestrel-containing preparations can aggravate these problems and should be avoided in these cases. Drospirenone (DRSP)-containing COCs may be the better choice due to the anti androgenic properties.
Women using oral contraceptives typically have a lighter menstrual flow for a shorter number of days than non-users and usage can decrease the incidence of iron deficiency anemia. Thus, oral contraceptives are used in the treatment of dysmenorrhea, menorrhagia, and endometriosis. They are useful for treatment of women with a history of irregular menses as well, such as hypothalamic amenorrhea, polycystic ovarian syndrome, and the perimenopausal woman. They can reduce the symptoms associated with premenstrual dysphoric disorder. Because they inhibit ovulation, COCs are useful in the suppression of ovarian cysts. Postmenopausal hip fracture rates are reduced in women who used combined contraceptives in their 30s. Use of oral contraceptives is also associated with a reduction in rates of benign breast disease, ovarian cancer, and endometrial cancer. Oral contraceptives are often used in perimenopausal women to relieve vasomotor symptoms.
Particular Thrombotic Risks
While all COCs carry an increased risk of thrombotic events, the risk is overall relatively low. Recent evidence suggests that oral contraceptives containing DRSP are linked to a disproportionate increase in thrombotic events. The FDA concluded that additional warnings were necessary on those oral contraceptives, but did not remove them from the market. The warnings include the following: Combined oral contraceptives containing DRSP may be associated with a higher risk of venous thromboembolism (VTE) than COCs containing levonorgestrel or some other progestins. Epidemiologic studies that compared the risk of VTE reported that the risk ranged from no increase to a 3-fold increase. The risk of VTE associated with pregnancy (5-20/10,000 women-years) is greater than the risk associated with any COC (3-9/10,000 women-years), including DRSP-containing COCs. Before initiating Beyaz, Safyral, Yasmin, or Yaz in a new COC user or a woman who is switching from a contraceptive that does not contain DRSP, consider the risks and benefits of a DRSP-containing COC in light of her risk of a VTE.
Progestin-only pills (or minipills) are associated with more breakthrough bleeding than combination pills and have slightly higher failure rates. The only mini-pill available in the US contains 35 mcg of norethindrone, marketed as Micronor or NorQD. Irregular bleeding, weight gain, and breast tenderness are the most common side effects. Progestin-only pills are a good option for patients who need to avoid estrogen, such as those with increased thrombotic risk. They need to be taken precisely at the same time each day, as delaying ingestion by as little as 3 hours can decrease efficacy in contrast to combined oral contraceptive pills.
Depot Medroxyprogesterone Acetate
Depot medroxyprogesterone acetate (DMPA; Depo-Provera) is progesterone that prevents ovulation in addition to causing changes in cervical mucus and the endometrium. It is given as an injection of 150 mg in the buttocks or upper arm within 5 days after the beginning of the normal menstrual cycle and is repeated every 3 months (13 weeks). There is now a newer formulation in which 104 mg is injected subcutaneously in the upper thigh or abdominal wall area by the patient herself at home. This is also injected every 3 months (13 weeks). Both formulations are more effective than oral contraceptives.
Side effects include irregular bleeding, weight gain, headache, mood change, abdominal pain, dizziness, weakness or fatigue, and breast tenderness. After 1 year of use, 50% of women have amenorrhea. This is not harmful, and periods return shortly after the drug is stopped. DMPA is safe, reversible, maintains spontaneity, and has noncontraceptive benefits similar to those of oral contraceptives. Ovulation is suppressed for at least 14 weeks, so a delay of up to 1 week in the next injection is acceptable. Women with a lapse of more than 14 weeks should have pregnancy ruled out. There is reduced menstrual cramping and pain, fewer periods, and lower chance of anemia. Fertility usually returns within 6 to 9 months after stopping but can take up to 18 months.
Depot medroxyprogesterone acetate works by suppressing ovulation and estradiol production. Patients taking DMPA are advised to exercise and take adequate amounts of calcium. In 2004, the FDA issued a black box warning for DMPA discouraging its use for longer than 2 years because the longer use would lead to bone loss from which the woman may never recover. In 2008, the American Congress of Obstetricians and Gynecologists (ACOG) issued a statement indicating that DMPA can be used for longer than 2 years. According to the ACOG guidelines, while DMPA has been associated with bone loss, it is temporary and the amount of loss is similar to that of other causes such as pregnancy and breast feeding. The evidence suggests that the bone mineral density in most women will return to baseline levels by 1-2 years after stopping DMPA. There is no need to monitor bone density in women taking DMPA. The advantages of DMPA outweigh the theoretical risks and there should be no arbitrary cutoff on length of use, particularly in adolescents.
Norplant was originally marketed in the US in 1991 as the first implantable contraceptive device. Norplant consists of 6 (2.4-mm Ã— 34-mm) silicone rods, each filled with 36 mg of levonorgestrel, implanted subdermally in the upper arm. The method is effective for 5 years. Norplant distribution in the US ended in 2002; limited supplies remained available until 2004.
In 2006, Merck received FDA approval for the implantable contraceptive device called Implanon. This single-rod progestin implant is placed subdermally in the inner arm. Contraception is provided by slow release of 68 mg of etonogestrel, which is initially released at 60 mcg to 70 mcg per day. The dosage decreases to 35 mcg 45 mcg per day at the end of the first year, to 30 mcg to 40 mcg per day at the end of the second year, and then to 25 mcg to 30 mcg day at the end of the third year. As of late 2011, the company introduced a new product called Nexplanon which is similar to Implanon but is radio-opaque, and hence can be localized by an ultrasound, Ã—-ray, computed tomography (CT) scan, or magnetic resonance imaging (MRI). It also has an insertion device that is somewhat easier to use.
Side effects include spotting, irregular bleeding, and amenorrhea. Irregular bleeding is the primary reason for discontinuation. Fluid retention, weight gain, and breast tenderness are less common. Potential complications of insertion include infection, hematoma formation, local irritation or rash, expulsion, and allergic reactions. A single case of injury to the branches of the medial antebrachial cutaneous nerve during insertion has been reported. Nerve injury can result in impaired sensibility, severe localized pain, or the formation of painful neuroma.
Insertion is an office procedure done with or without local anesthesia. The rod can be removed at any time, but it must be removed at the end of 3 years. Ovulation resumes shortly after removal. Correct insertion technique and timing of insertion play major roles in the effectiveness of Implanon/Nexplanon. The FDA has mandated that providers undergo special training to place and remove the devices, which should be inserted between day 1 and day 5 of the menstrual cycle. If implantation is performed during other days of the menstrual cycle, a pregnancy test must be done as well. The patient should be advised to use another method of contraception for at least 1 week after insertion.
Implanon and Nexplanon work by suppressing ovulation. These implantable devices are among of the most effective forms of birth control with a failure rate of 0.05%. They require no user action and does not inhibit spontaneity. However, a major side effect is irregular bleeding, occurring in as many as 33% of users. This results in a fairly high discontinuation rate.
The transdermal contraceptive patch (Ortho Evra) consists of 3 layers. The middle layer contains norelgestromin and ethinyl estradiol. The inner layer is an adhesive and the outer is a protective cover. The patch contains 150 mcg of norelgestromin and 20 mcg of ethinyl estradiol. The first patch should be applied within the first 5 days of the menstrual cycle, and backup contraceptives should be used concomitantly for 7 days. A new patch should be applied every week for 3 weeks, followed by 1 patch-free week.
The patch exposes women to higher levels of estrogen than do most oral hormonal contraceptive pills. The FDA has added new warnings that users could have twice the risk of blood clots than users of oral hormonal contraceptives due to higher levels of estrogen exposure.
Application sites include the buttocks, abdomen, outer arms, and torso, except the breasts. The patch may be a good option for women who have difficulty adhering to other hormonal contraceptive regimens.
Physicians must balance the higher estrogen exposure against the chance of pregnancy. The patch completely detaches in 2% to 6% of cases. If it is replaced within 48 hours, no backup contraception is needed. If the patch-free interval exceeds 2 days, pregnancy should be ruled out, a new patch should be placed, and a backup contraceptive method should be used for 7 days. In case of skin irritation, the patch should be removed and a new patch applied to another site. Women weighing more than 198 pounds should not use the patch because its effectiveness is reduced. Ortho Evra offers no protection against STDs.
The NuvaRing is a nonbiodegradable, flexible vaginal ring made of a polymer that contains ethylene vinyl acetate and magnesium stearate. The outer diameter of the ring is 54 mm, and the cross-sectional diameter is 4 mm. It releases 120 mcg of etonogestrel and 15 mcg of ethinyl estradiol daily. The ring is left in place for 3 weeks, followed by 1 ring-free week to induce menstruation. Efficacy is similar to that of COCs if used as directed.
Vaginal discharge, vaginitis, and irritation can occur. Side effects are otherwise similar to those of oral combination pills.
The ring can be inserted at any time during the first 5 days of the menstrual cycle. A new ring should be inserted each month. The hormonal ring provides good cycle control.
If the ring is expelled during the first 3 weeks of use, it should be washed with lukewarm water and then replaced. If the ring-free interval is longer than 3 hours, a backup contraceptive method should be used concomitantly for 7 days. The ring should never be left in place for more than 4 weeks. When used in a continuous fashion, a new ring is placed every 3 weeks avoiding a withdrawal menses. It provides no protection against STDs.
Current intrauterine devices (IUDs) are safe and slightly more effective than oral contraceptives (Table 1). The copper IUD is a T-shaped device made of soft, flexible plastic with threads on the end that extend from the cervix and into the upper vagina. The copper IUD induces a foreign-body reaction in the endometrium and cervical mucus that prevents viable sperm from reaching the fallopian tubes. It has an effective life of 10 years. Expulsion of the copper IUD occurs in 5% of women during the first year.
The levonorgestrel-releasing IUD is a T-shaped polyethylene device. The frame is 32 mm in both horizontal and vertical directions. The vertical stem contains a mixture of silicone and 52 mg of levonorgestrel surrounded by a silicone and plastic capsule. The device releases 20 mcg of levonorgestrel daily and has an effective life of 5 years. This device also works predominantly by causing changes in cervical mucus quantity and quality as well as changes in tubal transport of sperm and egg. In the first year of use, ovulation is often inhibited, however after that the majority of cycles are ovulatory. For complete suppression of ovulation, a daily intrauterine release of > 50 mcg of LNG is required. With Mirena, 20 mcg/day of LNG is released. Determination of plasma estradiol and progesterone (P) levels indicates that women using Mirena generally have normal ovulatory cycles but unlike women who use the copper IUD, these women tend to have significantly decreased menstrual flow. The rate of amenorrhea in women who have used the device for longer than 12 months is 20% to 80%. In October 2009, FDA approved Mirena for the treatment of heavy menstrual bleeding.
Side effects associated with IUDs include cramping during insertion, bleeding, pelvic inflammatory disease, and perforation of the uterus. Expulsion rates for Mirena are a slightly higher than those for copper IUDs. The user can be taught to detect expulsion. There is a mildly increased risk of ectopic pregnancy. Ovarian cysts are 3 times more common in users of this device.
Overall, the IUD is an excellent contraceptive choice with few contraindications. It is not user dependent, spontaneity is maintained, and the failure rate is very low at 0.2%. Fertility returns rapidly after discontinuing use of the device.
Prescription barrier methods include the diaphragm, the cervical cap, and the cervical shield (Table 2). They cover the cervix and prevent the entry of sperm. These devices are less effective than hormonal forms of contraception. This decreased efficacy is partially due to the dependence on correct placement by the patient as well as consistent usage. The female condom and spermicides as well as male condoms are nonprescription barrier methods.
Table 2: Select Barrier Contraception Methods
|Method||Left in Place After Intercourse (Hours)||Remove Within (Hours)|
|Prentif (latex) cervical cap||8||48|
|FemCap (silicone) cervical cap||6||48|
The diaphragm is a shallow dome-shaped silicone or latex disk with a flexible rim. It sits against the pubic bone in the vagina and covers the cervix. The effectiveness depends on the proper fit as determined by the physician. Refitting should occur if there is a pregnancy or the patient's weight changes by more than 10 pounds. The patient needs to be trained in insertion and removal. Spermicide should be applied to the device before insertion. The diaphragm must remain in place for 6 hours after intercourse and for no longer than 24 hours.
The cervical cap is smaller than a diaphragm. It fits securely in the vagina, covering the cervix, and must be fitted by a physician. Two types are available. The latex cervical cap (Prentif) has a firm, flexible rim and comes in 4 sizes ranging from 22 to 31 mm. The firmer silicone FemCap comes in 3 sizes, ranging from 22 mm to 30 mm. The sizing is determined by the number of pregnancies the woman has had. The patient needs to be trained in insertion and removal. Spermicide must be used with the device. The cap can be inserted up to 8 hours before intercourse and should remain in place for no longer than 48 hours.
The cervical shield (Lea's Shield) is a dome-shaped disk made of silicone, manufactured as one-size-fits-all. It is held in place by the vaginal wall via a one-way valve that creates suction by venting trapped air between the shield and cervix. It acts by preventing sperm entry and has a strap for easy removal. Although it is not fitted by a physician, it is available only with a prescription. Spermicide should be applied to the device before insertion. It must be left in place for at least 8 hours after intercourse and for no longer than 48 hours. The most common complaint was discomfort by the male partner.
The female condom consists of a lubricated nitrile sheath 6.5 inches in length with a flexible ring on each end. One ring is inserted into the vagina much like a diaphragm, while the other remains outside, covering the labia, preventing the condom from becoming dislodged. Side effects include irritation and allergic reactions. The female condom offers protection against most STDs. The most common complaint is difficulty in insertion as well as noise during intercourse. This can be reduced by adding additional lubrication. This method is used by < 1% of women in the US.
Side Effects, Advantages, and Precautions
Side effects of barrier methods include vaginal irritation; allergic reactions to latex, silicone, or spermicide; urinary tract infections; and the rare risk of toxic shock syndrome if the device is left in place for too long. These methods are safe, effective, and reusable, and have no effect on the menstrual cycle. These methods are less effective than hormonal contraceptives. Use of cervical shields can lead to falsely abnormal Pap tests. A woman who has abdominal or pelvic surgery, a pregnancy lasting longer than 14 weeks, or any significant weight change should be refitted for the device. To protect against pregnancy, the devices should be left in place for a minimum of 6-8 hours after intercourse and then removed within 24-48 hours to decrease the risk of infection.
Spermicides are a chemical barrier method containing nonoxynol-9, which kills sperm or renders them inactive. Spermicides come as in the form of foam, cream, gel, suppository, and contraceptive film. Side effects include irritation, allergic reaction, and urinary tract infections. Spermicides are inexpensive and do not require a prescription. They offer some protection against STDs, and they are less effective by themselves than other methods. Ideally they should supplement mechanical barrier methods.
The contraceptive sponge is a soft polyurethane sponge impregnated with the nonoxynol-9. The soft nature of the product causes it to feel like vaginal tissue so that it is not noticed by the partner. It is designed to gradually release the spermicide over a 24-hour period without the need for additional spermicide, should repeated intercourse take place. The effectiveness of the sponge when used appropriately and consistently is 89% to 91%. Like the cervical cap, cervical shield and diaphragm, the sponge should be kept in place for at least 6 hours after intercourse to ensure effective contraception. However, it should not be left in place for more than 30 hours after insertion. It is available over the counter without a prescription.
Hysteroscopic sterilization is a method of permanent sterilization that uses a transcervical approach. The micro-insert consists of a stainless-steel inner coil, an elastic outer coil, and polyethylene fibers. The coil is inserted into the uterine end of the fallopian tube using a hysteroscopic technique. The outer coil expands to anchor the insert. The polyethylene fibers expand and cause inflammation and extensive fibrosis, resulting in permanent occlusion of the fallopian tubes by 12 weeks. Failure to correctly place the micro-inserts can lead to expulsion. Women should use a backup method for 12 weeks. Hysterosalpingography must be done at the end of 12 weeks to confirm tubal occlusion.
The advantage over traditional sterilization is that hysteroscopic sterilization can be performed in the office under local anesthesia. Side effects include pain during and after insertion, as well as risk of failure, and a small increased risk of ectopic pregnancy should a failure occur. The failure rate for hysteroscopic sterilization is approximately less than 0.2%.
Tubal ligation is a surgical procedure requiring general or regional anesthesia, in which the fallopian tubes are occluded. It is the most common surgical procedure performed on women and the most common form of contraception in women aged > 35 years. This is accomplished by surgically removing a portion of the tube and applying an inert clip or using electrocautery to destroy a section of tube. This can be accomplished in the immediate postpartum period as well as during an interval procedure. Although it can be performed as an open procedure, it is usually accomplished laparoscopically or via a small infraumbilical incision during the postpartum period. The surgery takes about 30 minutes. The procedure does not affect the menstrual cycle and is not associated with painful menses or more frequent or heavier menses. There are the usual risks of surgery, such as bleeding, infection, side effects of anesthesia, and bowel or bladder injury. There is a failure rate of about 1 out of 200 in the first year after the procedure with an increased risk of ectopic pregnancy, should a failure occur.
Natural family planning
Natural family planning restricts intercourse to naturally infertile periods. Various methods are used to identify these infertile periods. The method begins with the knowledge that sperm can live in the female reproductive tract for up to 3-5 days, whereas the egg can survive for 24-48 hour after ovulation. Thus infertile days are restricted to 2 days after ovulation and continue until the next menses.
The calendar method is based on calculations of previous menstrual cycles. The woman needs to keep track of her cycles for 8-12 months. The first day of fertility is determined by subtracting 18 days from the length of the shortest cycle, and the last fertile day is determined by subtracting 11 from the length of the longest cycle. The time in between these is considered the fertility window. Ovulation is expected within this time frame. Women who have no variation in the length of their menstrual cycle will place ovulation at midcycle on day 14. However, this method does not allow for future changes in the menstrual cycle that can lengthen the follicular phase, thus placing ovulation later in the cycle than what was previously presumed to be safe.
In the cervical mucus method, the days just before and after ovulation are determined by checking cervical mucus. Cervical mucous is checked daily and tracked. Mucus becomes copious, stretchy and clear at the time of ovulation and intercourse should be avoided until 4 days after the peak day.
In the symptothermal method, daily basal body temperature be taken at the same time every day and is recorded on a chart. Body temperature rises 2 days before ovulation, however it only rises by 0.4Â° F to1Â° F and it can be influenced by illness. Consistency of cervical mucus is also monitored. Both of these methods are used to increase ovulation prediction.
The lactation amenorrhea method is based on natural postpartum infertility, when a woman is amenorrheic and exclusively breastfeeding. The infant's suckling suppresses production of hormones. All 3 criteriaâ”€exclusive or nearly exclusive breast-feeding, no menses since delivery, and < 6 months postpartumâ”€must be satisfied to effectively use this method. It has about 25% failure rate in the first year.
Emergency oral contraception
There are 3 methods of oral emergency contraception that are approved by the FDA and available in the US. All of them should be used as soon as possible after unprotected intercourse. The Yuzpe regimen, originally marketed as Preven, is no longer available; however, it can be recreated by using a variety of combined estrogen and progestin daily birth control pills. The incidence of adverse effects of nausea and vomiting is higher with this method than with a progestin only method.
Next Choice is a 2-step medication. It consists of 2 0.75-mg levonorgestrel pills taken 12 hours apart. The first pill should be taken within 72 hours of unprotected intercourse. The dose should be repeated if vomiting occurs within 1 hour of taking the first dose. A similar medication is Plan B One Step consists of 1 pill of levonorgestrel 1.5 mg taken as a single dose within 72 hours of unprotected intercourse. If vomiting occurs within 2 hours of taking this medicine, then the dose is repeated. Both have been approved for sale behind the counter by pharmacists to women age 17 and older presenting photo identification. Women under 17 years of age will need a prescription to obtain the medication.
A newer oral method is Ella, consisting of a single dose of ulipristal 30 mg. This medication can be taken as late as 120 hours after unprotected intercourse. Unlike the previously mentioned agents, ulipristal is a progesterone agonist/antagonist. It is the only emergency contraceptive that is able to delay ovulation once the LH surge has occurred. A prescription is needed to purchase this medication. The dosage should be repeated if vomiting occurs within 3 hours of taking the medication. It is slightly more effective than levonorgestrel.
Emergency contraceptive pills are not teratogenic. Thus, a pregnancy test is not required before treatment. The method of action is prevention of ovulation and alteration of tubal egg and/or sperm transport. They will not disrupt an already established pregnancy and are not an abortifacient. They are most effective if taken as soon as possible after unprotected intercourse. Menses should be expected within 1 week of use. The failure rate is 0.4% when treatment is initiated within 24 hours and 2.7% when treatment is initiated 48 to 72 hours after intercourse. Side effects are nausea and vomiting.
The copper IUD can also be used as an emergency contraceptive, but it has to be inserted by a trained health care professional within 120 hours (5 days) of unprotected intercourse. It is more effective than the previous methods, reducing the risk of pregnancy to < 1%.
The range of available contraceptive options has increased markedly over the past 5 years. This progress is likely to continue as consumers seek safer, more-effective contraceptive methods. Improved counseling and knowledge should lead to more consistent and correct use of contraceptives and decreased numbers of unplanned pregnancies.
- Approximately 50% of pregnancies are unplanned, making unintended pregnancy a major health problem.
- The most effective and reversible contraceptive methods include the oral contraceptive, injectable contraceptive, implantable contraceptive, hormonal ring, and intrauterine devices.
- Barrier methods of contraception are less effective than hormonal forms of contraception
- Risks and benefits of each method should be discussed with patients and a joint decision should be made to increase compliance
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