All the progestin only contraceptives are approved for patients at higher risk of deep venous thrombosis and pulmonary embolism (DVT/PE), such as patient with malignancies. They are not associated with an increased risk of high blood pressure and cardiovascular disease. An added benefit is menstrual lightening or suppression, which differs according to each one of them. The only absolute contra-indications to progestins are pregnancy and a personal history of hormone dependent breast cancer. Progestin-only contraception may be provided as an oral medication, injectable form, or an implant. Their mechanisms of action for contraception are: increasing viscosity of cervical mucus, ovulatory suppression and endometrial thinning.
Progesterone only pills must be taken at the same time every day. Its efficacy relies on compliance with a typical use failure rate of 8-9%. (10) Up to 10% of users will develop amenorrhea after one year of use. Side effects may include breakthrough bleeding, headaches, nausea, acne and breast tenderness. Its risks are minimal. (8)
Injectable Contraceptive (Depot Medroxyprogesterone Acetate)
DMPA is given as an intramuscular injection, which is administered every 12 weeks. Its efficacy relies on compliance with a typical use failure rate of 3 to 6% and perfect use of 0.3%. (10) Up to 60-90% of users will develop amenorrhea after 1 year of use. Side effects include initial breakthrough bleeding, weight gain, headaches, nausea, breast tenderness, acne and mood disorder.
In 2004, the FDA issued a black box warning stating that prolonged us of DMPA may result in significant loss of bone mineral density (BMD). Following this event, the WHO collected experts reviews concluding that DMPA is associated with a risk of reversible BMD reduction during treatment, which has not been proven to increase fracture risk. (11) On average, patients on DMPA have a weight gain of less than 2 kg per year. (12) However it has also been shown that certain populations, such as those that are obese or more sedentary, are more at risk for weight gain with DMPA. (13, 14).
Long-acting reversible contraception (LARC)
LARC methods are the most effective birth control methods with a failure rate of < 1%. In September 2014, AAP (American Academy of Pediatrics) published a new recommendation stating that the first-line contraceptive choice for adolescents who choose not to be abstinent should be a LARC method. Their safety and efficacy in adolescents has been well demonstrated and are recommended for teenagers. (15)
LARCs include the intrauterine device (IUD) and the birth control implant. In the Contraceptive CHOICE project, all contraceptive options were provided to participants at no cost for the duration of the 2-3 year project. Seventy-five percent of participants in the CHOICE project chose LARC methods; this is astounding compared to the national average of 8.5% at the time. (16) Adolescents chose LARC at similar rates (69-71%); however the younger adolescent population appeared to favor the LNG implant system. (17) A recent analysis of the CHOICE project evaluated contraception continuation in teenagers and young women and demonstrated high rates of continuation and satisfaction with LARC similar to that in the older adult population. (18, 19) It has also been shown that adolescents are more likely to continue LARC than non-LARC contraceptive methods. (20) The continuation rate of LARC methods in teenagers and young women has been studied at 81%. (19)
The subdermal rod, marketed as the Nexplanon, measures 4cm by 2 mm, and constantly releases Etonogestrel. It is currently approved for contraception at three-year duration. The device is inserted superficially in the upper arm during a simple office procedure by a trained physician or midlevel provider, requiring only local anesthesia. (21) The risks of the procedure are rare, but include, bleeding, hematoma formation and infection. The main side effects are irregular, unpredictable vaginal bleeding (50%), acne (12%), headaches (16%), weight gain (12%) and mood disturbance (6%). About 11% of patients become amenorrheic after 1 year of use. (22) Removal requires a second small office procedure with local anesthetic and a small incision and similar risks. Removal can be challenging due to an inability to palpate the rod, a breakage of the implant, or growth of adhesions around the device.
Continuation rates have been shown to be higher than 80% after 1 year of use in one study. (19) Other studies have found higher discontinuation rates with an average of 35%, and the most frequent reason for discontinuation was persistent bleeding irregularities. (22)
This device, marketed as the Mirena, is T-shaped and contains a barrel with 52mg of Levonorgestrel. It is inserted inside the uterine cavity, through the cervix using a speculum and indicated instruments. This is a simple office procedure in most instances. Levonorgestrel is released at an initial rate of 20mcg/day that decreases to 10-14 mcg per day over its currently approved five year duration of use. (8) The main risks are uterine perforation (1/1000) (23), IUD expulsion (6%) (19), and slight increase in PID in the 20 days following insertion (1%). (24) It is important to clarify that overall, IUD use in teenagers is encouraged and that it does not increase risk of PID, STI and infertility. Cervical screening for Chlamydia and Gonorrhea should be done on all women at high risk for STIs, therefore all adolescents. Side effects are minimal but include limited irregular vaginal bleeding, acne, headaches and mood disturbance. Other benefits include menstrual lightening (up to 90% of flow) or suppression (in 50% at 24 months of use), alleviation of dysmenorrhea and pelvic pain, and reduction of risk of endometrial cancer. There is limited evidence for or against IUD use in cancer related immunocompromised women, however the CDC and WHO both support its use and are reassuring about its safety based on other types of immunocompromised patient data. (10)
A lower dose levonorgestrel IUD became available on the market in the United States in 2013, marketed as Skyla. This IUD contains 13.5 mg of levonorgestrel, that is initial released at a rate of 14 mcg/day that decreases to 5 mcg/day overs its approved three year duration of use. It has a slightly smaller size and diameter, which theoretically may make it more suitable for placement in certain populations with a small uterine cavity or cervical stenosis. The low dose levonorgestrel IUD is not currently approved for the treatment of menorrhagia and has a lower likelihood of amenorrhea (13% vs 24%) compared with the higher dose IUD. (25)
Overall, the levonorgestrel IUDs have been proven to be a highly effective birth control method that is both beneficial and safe. Non-sexually active teenagers and young adults usually tolerate insertion very well. In patients who are unable to tolerate in-office placement, such as those with special needs, the IUD can be placed under general anesthesia. It is best to attempt to combined placement with a previously scheduled procedure, such as a line placement or biopsy, however they can also be scheduled independently.