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Progestin Only Contraceptives and Their Use in Adolescents: Clinical Options and Medical Indications

October 23, 2005

By Burkett, Amy M; Hewitt, Geri D

This article reviews progestin only contraceptives and their use in adolescent women. Young women requiring hormonal contraceptives for birth control or medical indications may prefer or require a nonestrogen containing product. This article reviews the products currently available, those soon to be released, and those under development. Many relatively common clinical situations preclude the use of estrogen-containing contraceptives or combination hormonal contraceptives, and those also will be outlined.

Progestin only hormonal contraceptives

Depot medroxyprogesterone acetate

Depot medroxyprogesterone acetate (DMPA) is discussed in detail in another section, but warrants brief mention here because it is used so widely. DMPA is given intramuscularly every 12 weeks and works by suppressing the luteinizing hormone (LH) surge and inhibiting ovulation [I]. Failure rate is less than 1% over 1 year of perfect use, but with typical use, the failure rate is 3% [2]. The most commonly experienced adverse effect is menstrual irregularity, including amenorrhea [I]. Other potential adverse effects include depression, weight gain, and a longer interval of return to baseline fertility when compared with oral contraceptives [3]. There is also increasing concern regarding bone mineral density loss with use in patients younger than 14 and with long-term use. This concern has led the manufacturer to change the package insert to limit the duration of use to 2 years unless no other hormonal contraceptive method is available [4,5].

Progestin only pills

Progestin only pills come in three separate formulations in the United States. Micronor and Nor-QD each contain 0.35 mg of norethindrone; Ovrette contains 0.075 mg of norgestrel. Progestin only pills are all active pills, with no inert pills or placebos, and they need to be taken daily, at the same time (Table 1) [I]. This required level of diligence can be a challenging obstacle for adolescent use. Progestin only pills have a perfect use failure rate of 0.3%. Because it must be taken at the same time every day, its typical use failure rate is upwards of 10% [2]. The progestin only pill works by suppressing ovulation, thickening cervical mucus, and causing atrophy of the endometrium [1,6], thus creating an inhospitable uterine environment to the sperm and ovum. Like all oral contraceptives, the progestin only pill will not disrupt an implanted pregnancy, cause miscarriage, or birth defects [7]. Adverse effects include amenorrhea, intermenstrual spotting, and altered menstrual flow. Up to one-third of women who are using these pills while not lactating will experience an abnormal bleeding pattern. Patients should be counseled regarding longer cycles and intermenstrual spotting, as these are the most common complaints leading to discontinuation. Patients using them while lactating are more likely to experience amenorrhea. This effect likely is related to lactational amenorrhea and is well tolerated, as the discontinuation rate in the lactating population is lower. Although menstrual irregularities may be more common in nonlactating patients using progestin only pills compared with estrogen-containing pills, headaches and breast tenderness are less common [6].

Table 1

Difference between progestin-only and combined hormonal contraceptives

Implanon

Implanon is a plastic polymer rod implant containing etonogestestrel that is available only in Europe [8], but it has received Food and Drug Administration (FDA) approval [9] and will to be released in the United States soon [I]. Implanon is inserted by a health care professional underneath the skin to provide long-term (up to 3 years) contraception [8]. Like other forms of hormonal contraception, the mechanism of action with the contraceptive rod is inhibition of ovulation [I]. Implanon is an excellent hormonal contraceptive option for young women, because there is little need for ongoing patient compliance after insertion, and the pregnancy rate is remarkably low. An initial study published in 1999 reported no pregnancies in its study population, which included over 1200 woman-years. Norplant was a contraceptive rod system with six silastic rods containing levonorgestrel. When inserted under the skin, it was effective for up to 5 years [1O]. Researchers feel comfortable projecting Implanon’s contraceptive efficacy to be comparable to Norplant’s, which had a 0% to 0.6% failure rate in the first 3 years of use and a 0.6% to 1% failure rate at 5 years of use [11,12]. Implanon has distinct advantages over Norplant directly related to its development into a single rod with a different plastic polymer that will allow greater ease of insertion and removal [8].

Implants are well accepted by women. In a study looking specifically at an adolescent population, 93% were satisfied with Norplant. Implanon should be as well accepted as Norplant or even more so given its ease of insertion and removal. Adolescents tend to choose an implant after a contraceptive failure, particularly one resulting in pregnancy. They also switch to an implant when they experience adverse effects from other methods. Some simply choose implants because they like the device’s convenience and ease of use [13]. Patients need to be counseled to expect altered bleeding patterns ranging from amenorrhea to prolonged and heavy menstrual flow; these are the most common reasons sited for early removal of Implanon. Other reasons sited include desired pregnancy, worsening of acne, weight gain [10], breast tenderness, and headache [14]. Most adverse effects experienced by patients using Implanon were not bothersome enough for the patient to have the device removed [14].

Emergency contraception

Up to 30% of patients have never heard of emergency contraception, and only 10% know how to obtain it [15]. Emergency contraception is described in detail elsewhere in this issue; this article briefly describes the progestin only method. There are three common pill regimens available, the Yuzpe Method, Plan B, and low- dose mifepristone [16,17]. Plan B is the progestin only method of emergency contraception. It contains two 0.75 mg doses of levonorgestrel, which are to be taken 12 hours apart. It is highly effective in preventing pregnancy after an act of unprotected intercourse. When used in the first 24 hours after unprotected intercourse, one study found only 2 of 450 women became pregnant. Although the method is most effective in the first 24 hours, it can be used up to 72 hours after unprotected intercourse [18]. Emergency contraception can be very helpful to young women who experience rape, sexual abuse, contraceptive failure, or a spontaneous, unpredictable sexual encounter where contraception was not used or planned for in advance. Although progestin only emergency contraception will not harm an existing pregnancy, the only contraindication to its use is pregnancy [7]. Therefore if a clinician is contacted regarding a patient’s need for emergency contraception, they can simply have the patient do a home urine pregnancy test and, if negative, call in a prescription to a local pharmacy for “Plan B, to use as directed.” It is important to initiate the therapy as soon as possible after the act of intercourse. The young woman can follow up in the office at an appropriate interval for contraception counseling, sexually transmitted infection (STI) testing, and a follow-up pregnancy test. Adverse effects are less common with plan B than the other methods, but they include nausea, vomiting, breast tenderness [18], and irregular bleeding patterns [19]. These patterns include spotting, shortened interval to menses, and lighter or heavier menses [19]. Teenagers should not mistake spotting for a light menses, as spotting does not always indicate success of emergency contraception [18,19]. Studies show that adolescents who are given emergency contraception before a method failure (advance provision) are more likely to use it than those who have to obtain it after unprotected intercourse has occurred. These data support providing all sexually active adolescents prescriptions for emergency contraception [20].

Intrauterine devices

Intrauterine devices (IUDs) have a long and mixed history as contraception in the United States, much of which stems from the now obsolete Dalkon Shield [21]. IUDs often are not considered a viable method of contraception in the adolescent population, but research shows that in a carefully screened population, the device can be successful. Adolescents should be mutually monogamous, placing them at low risk for STIs. They do not have to be parous, but there is a higher expulsion rate in the nulliparous patient [22]. The Mirena IUD (Table 2) contains a progestin. It works by slowing releasing levonorgestrel into the endometrial cavity over a 5-year period and has a failure rate of 0.1% [2]. The device works locally, causing thickened cervical mucus and an atrophie endometrium. This environment is toxic to sperm because of local inflammation [23]. The ParaGard IUD is not hormonally active but contains copper, again causing endometrial inflammation that is toxic to sperm (Fig. 1). Both IUDs are spermicidal. The copper IUD is effective for up to 10 years after insertion [24] and has a failure rate of 0.8% per year with typical use [2]. Most women experience a decrease in menstrual bleeding whil\e using the Mirena IUD, but bleeding profiles when using the nonhormonally active IUD can be heavier than a patient’s preinsertion menses [24]. Because both devices are very effective in preventing pregnancy, the rate of ectopic pregnancy is lower than that seen in the general population [24,25]. The Mirena IUD is not recommended for patients with a history of ectopic pregnancy, as these patients were not included in the clinical trials [25]. Complications associated with IUDs include uterine perforation during insertion, insertion-related endometritis [24], and increased dysmenorrhea that usually responds to nonsteroidal anti- inflammatory drugs (NSAIDs). The most common reasons patients request IUD removal are bleeding and pain [22]. Antibiotic prophylaxis at the time of insertion is recommended only for patients who receive prophylaxis for other procedures, such as dental work [24].

Table 2

Comparison of copper and progestin containing intrauterine devices

Fig. 1. ParaGard is made of soft white plastic in the shape of a small “T.” It is 1.375 inches long, with small amounts of copper wrapped around the stem and arms. The copper enhances effectiveness. (From www.paragard.com.)

Future methods

Researchers continue to strive for hormonal contraception that is simple, effective, and user friendly. To that end, there are efforts to create an implant that is biodegradable when exposed to body fluids. Such a device is Capronor, a capsule consisting of levonorgestrel, which slowly dissolves. A second device consisting of four to five pellets of norethindrone is in early development [1,2]. If successful, both devices would alleviate the uncomfortable process of removing a device, while still providing the long-term, effective, and effortless contraception many adolescents desire.

Vaginal rings as alternative delivery system are receiving attention also. A combination contraceptive ring containing both estrogen and progestin is already available in the United States. A progestin only ring is available in South America, indicated currently only for use during lactation. Further use and development of progestin only rings had been halted in the 1980s because of concern over adverse lipid profiles and vaginal lesions. There is a phase II trial underway looking at a nestorone-containing ring that could stay in place for 6 to 12 months in lactating women [26].

Clinical indications for progestin only contraceptives

Lactation

Some adolescent mothers are very interested in breastfeeding, and with appropriate education and support, they are successful at breastfeeding exclusively. Most clinicians are familiar with the use of the progestin only contraceptive methods during lactation. Because estrogen-containing hormonal contraceptives affect breast milk production, progestin only options are the preferred choice. Controversy exists regarding when to initiate progestin only contraceptives in the postpartum period. Most authorities, including the National Medical Community of Planned Parenthood Federation, agree that it is acceptable to begin them immediately postpartum, but the World Health Organization (WHO) and International Planned Parenthood Federation recommend waiting until 6 weeks postpartum [27]. Some clinicians prefer to wait until the 6 week postpartum visit to decrease the likelihood of abnormal bleeding [28] and to secure lactogenesis [29]. The authors’ practice has been to initiate progestin contraceptives before discharge from the hospital for several reasons. First, a significant proportion of teen mothers in their practice have initiated sexual activity before their 6-week follow-up appointment. second, few of their young mothers breastfeed exclusively, and third, compliance at the 6-week postpartum examination is often less than 100%. DMPA, progestin only pills, and contraceptive rods can be initiated before discharge from the hospital (Fig. 2). The progestin IUD is not approved by the FDA for use in lactating women [25]. Latino women with gestational diabetes are at increased risk of developing diabetes in the first year after delivery if they are lactating and using progestin only pills [3O]. Although this is not a contraindication to using progestin only pills in this population, it emphasizes the need for diabetes screening during this period (Fig. 3).

Fig. 2. Plan B. (From http://ec.princeton.edu/Pills/planb.html.)

Gynecologic disorders

Often times an adolescent may present to the pediatrician with gynecologic complaints, including dysmenorrhea, pelvic pain associated with endometriosis, polycystic ovarian syndrome, and anovulatory bleeding. Progestin only contraceptives may play a role in managing these common gynecologic complaints.

Medical problems

Although most adolescent women are healthy and without medical risk factors or disease, there are numerous health problems that can preclude a young woman from using estrogen-containing birth control methods (Table 3) [7,31]. Approximately 10% of adolescents are diagnosed with a major medical condition by the time they are 18 [32]. Therefore, practitioners should screen their patients for personal and family medical conditions that could affect their contraceptive choice. Screening questions should include personal or family history of neurological disorders, cardiovascular disease, sickle cell anemia, liver dysfunction, and diabetes. It should be noted that there are no medical conditions that preclude the use of progestin only emergency contraception [7].

Fig. 3. The implantable contraceptive rod.

Table 3

Medical conditions and their impact on hormonal contraceptive choice

Cardiovascular disease

Adolescents should be asked about cardiac disorders and cardiovascular risk factors when considering hormonal contraception. These risk factors include [34]:

* Smoking

* Diabetes

* Hypertension

* Family history of premature cardiac events

* History of cerebral vascular accident

* Low high-density lipoprotein (HDL) (less than 35)

* Elevated triglycerides (greater than 250)

* Elevated low-density lipoprotein (LDL) (greater than 160)

* Cardiac anomaly

Young women may not remember the specific disease entity, but one can screen for medication use, emergency room visits for chest pain, use of antibiotics during dental procedures, chest surgery, or a history of having an echocardiogram. Young women with asymptomatic mitral valve prolapse (MVP) can use combination hormonal contraception safely [7,33]. Patients with symptomatic MVP or MVP associated with smoking, history of thromboembolic events, or coagulopathy should not use combination hormonal contraception but can use progestin only birth control methods safely [33]. Teenagers with other uncomplicated cardiac valvular syndromes may use combination hormonal contraceptives [7]. Cardiac valvular syndromes complicated by pulmonary hypertension, risk of atrial fibrillation, or history of subacute bacterial endocarditis preclude the use of combination hormonal contraceptives. These patients can use progestin only methods safely [7]. Patients with valvular disease other than asymptomatic MVP require antibiotic prophylaxis against bacterial endocarditis at the time of IUD insertion [7,33].

Current WHO recommendations suggest that women with hypertension should avoid combination hormonal contraception and would be served better with the use of progestin only contraceptive methods. Young women with a history of hypertension limited to pregnancy can use combination hormonal contraception safely. Patients with uncontrolled hypertension (systolic blood pressure greater than or equal to 160 or diastolic blood pressure greater than or equal to 100) or multiple cardiac risk factors should avoid DMPA, but they may use any other progestin only methods safely [7].

More infants born with cardiac anomalies are living well into their reproductive years and require counseling about choosing acceptable methods of birth control. Pregnancy can expose these patients to significant risk of maternal morbidity and mortality. Many of these disorders, even when repaired, are complicated with other cardiac diseases, which preclude the use of combination hormonal contraceptives. Although there is an array of cardiac syndromes, generally the use of progestin only contraceptive methods is safe [32]. Both IUDs are also an acceptable choice in this patient population [7,32].

Box 1. Inherited hypercoagulable disorders

Teenagers with an active or resolved DVT (deep vein thrombosis) or PE (pulmonary embolus) cannot use combination hormonal contraceptives. In the patient with an active DVT or PE, progestin only methods should be avoided also, but they can be used safely after resolution of the acute event. Family history of DVT or PE does not preclude a teenager from using combined hormonal contraceptive methods unless a clotting disorder also was diagnosed [7].

Patients diagnosed with hereditary thrombogenic mutations (Box 1) should avoid combination hormonal contraceptives, but they can use all types of progestin only methods safely. Current WHO recommendations maintain that routine screening tests for thrombogenic disorders are not required before prescribing combination hormonal contraceptives [7]. If a young woman reports a family history of acute thromboembolic events or thrombogenic mutations, however, appropriate screening tests should be done [7,34]. These tests include [36] (personal communication with P. Samuels, MD, December 2004):

* Genetic testing for factor V Leiden

* Genetic testing for prothrombin gene 2021OA

* Plasma levels of protein C, protein S, antithrombin

* PT/INR

* PTT

* Plasma levels of homocysteine (if elevated, consider genetic testing for methyleneterahydrofolate reductase homozygosity and cystathionine β-synthase deficiency

The most prevalent disorder diagnosed is factor V Leiden mutation, affecting 7% of Caucasians [34]. Young patients with a personal history of thrombosis in less comm\on places or without trauma should be screened for the acquired hypercoagulable disorders in addition to the heritable thrombogenic disorders. The American College of Obstetrics and Gynecology (ACOG) specifically suggests screening for antiphospholipid antibodies and anticardiolipin antibodies in this patient population, as these disorders can complicate pregnancy outcomes and are a contraindication to combination hormonal contraception [35]. In adolescents diagnosed with hypercoagulable disorders progestin only birth control methods can be used safely so long as the patient does not currently have a DVT or pulmonary embolus (PE). Combined hormonal contraceptive methods should be avoided [7].

The WHO does not recommend routine lipid profile screening in healthy adolescents before prescribing combination hormonal contraception [7]. If a screening lipid profile is done for other reasons and identifies a dyslipidemia, there are specific recommendations for the use of hormonal contraception. Adolescents with controlled dyslipidemias have no limitations on their contraceptive choice as estrogens have a positive effect on HDL and LDL. If a young woman has an LDL greater than 160 or other cardiac risk factors, however, she should not use combined hormonal contraception, because estrogens elevate triglycrides [32]. These patients may use progestin only methods safely [32,36]. Patients with dyslipidemias on combination hormonal contraceptives should have their lipid profiles followed closely [32].

Neurologic conditions

Screening questions for neurological disorders should focus on headaches and seizures. Teenagers with nonmigrainous or migrainous headaches without aura are not limited from use of combined hormonal contraceptives [7,37,38], Migraines with aura lasting longer than 1 hour or accompanied by neurological symptoms such as numbness, weakness, or tingling preclude the use of combined hormonal contraceptives. Additionally if patients with migraines have stroke risk factors, they should not use combined hormonal contraceptives [31,37,38]. If a young woman begins to experience auras while using a progestin only method, it should be discontinued [7].

Young women with seizure disorders need reliable contraception because of the teratogenicity of most anticonvulsants [31]. No seizure disorder precludes the use of combined hormonal contraception. Many anticonvulsants, however, decrease the efficacy of combined and progestin only hormonal contraception, primarily through enhanced liver activity [7,31]. DMPA is the least affected by this process, likely because the serum concentrations are higher compared with other methods [31]. Although some clinicians increase the dose of the hormonal contraceptive prescribed in patients taking anticonvulsants, it is uncertain whether this will increase its efficacy [7]. Patients on anticonvulsants may choose barrier methods and either IUD, as their efficacy is not affected by liver metabolism.

Diabetes

Adolescents with type 1, type 2, or a history of gestational diabetes mellitus can use any method of hormonal contraception safely unless there is end organ damage (nephropathy, retinopathy, or vascular disease). The presence of end organ damage precludes the use of combined hormonal methods, but these patients can use progestin only birth control methods, barrier methods, or either IUD safely [7,38]. Young mothers who had gestational diabetes should be screened for impaired glucose tolerance after delivery [39]. All diabetic women should be counseled about the importance of glycemic control, because hyperglycemia is related directly to an increased risk of birth defects. This illustrates the need for glycemic control when attempting conception and emphasizes the need for good, reliable contraception in patients with diabetes [4O].

Sickle cell disease

Sickle cell disease is not a contraindication to the use of combined hormonal contraceptives. Small controlled trials suggest that patients using DMPA experience fewer crises, and therefore ACOG considers it the method of choice in these patients [38].

Hepatobiliary disease

Some types of gallbladder and liver disease preclude the use of hormonal contraceptives. When screening for these disorders, clinicians should ask about jaundice after the newborn period, history of cholecystectomy, presence of gallbladder disease, medically imposed dietary restrictions, intravenous drug abuse, current and past sexual practices, and history of blood transfusion before 1992 or transfusion of clotting factors before 1987 [41]. Active hepatitis precludes the use of all hormonal contraceptives, but these patients may use barrier methods and copper IUDs. Patients with chronic hepatitis can use progestin only options, barrier methods, and both IUDs. Adolescents with liver tumors or mild cirrhosis should not use combined hormonal contraceptives, as they can exacerbate these disorders. These patients can use progestin only methods safely [7,42]. Young women with decompensated cirrhosis should avoid all hormonal contraception but may consider a copper IUD [7]. Patients with active gallbladder disease are candidates for progestin birth control, but they should not use combination hormonal contraceptives until after cholecystectomy [7]. Adolescents with Wilson’s disease should avoid the copper IUD and combination hormonal contraceptives but may use progestin methods safely. Any young woman who has received a liver transplant can use the progestin only methods safely, but the use of combined hormonal contraception is controversial. Patients taking combined hormonal contraceptives need to have liver function tests and cyclosporine levels monitored closely. Use of IUDs in liver transplant patients is also controversial because of their immunosuppression, which may cause an increased risk of ascending infection. There is also concern that the immunosuppressive agents may lessen the efficacy of the copper IUD, as its affects are thought to be exerted partially through the immune system [42].

Patient choice

Patient lifestyle always plays a role in the choice of contraceptive. Although choosing a contraceptive method, counseling adolescents, and sexual activity are addressed elsewhere in greater detail, it should be noted that DMPA and implantable devices often are chosen by young women simply because of ease of use. These methods do not require the adolescent to remember a pill every day, and they provide discreet, long-term contraception with minimal hassle.

Summary

Most adolescents are healthy and can use combined hormonal contraception safely. In clinical situations that preclude the use of these agents, the patient often can be served well by a progestin only method. The progestin only contraceptive options include pills, a long acting intramuscular injection, an implant, and a progestin IUD. Although the options vary in their efficacy, they are generally safe and well tolerated by adolescents. In particular, implants are suited well for adolescent use because of their low need for compliance and high efficacy and continuation rates. Pregnancy is the only contraindication to progestin only emergency contraception, and studies show advanced provision enhances its appropriate use in the adolescent population.

Acknowledgments

The authors would like to thank Ms. Laura Trout-Molton for her help in preparation of the final manuscript and Ms. Megan Dailey for her assistance in accessing numerous reference articles.

References

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Amy M. Burkett, MD, Geri D. Hewitt, MD*

The Ohio State University College of Medicine and School of Public Health, 516 Means Hall, 1654 Upham Drive, Columbus, OH 43210, USA

* Corresponding author.

E-mail address: hewitt-2@medctr.osu.edu (G.D. Hewitt).

Copyright Hanley & Belfus, Inc. Oct 2005




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