Progestins

1. An 18 yo nulligravid female is referred from her pediatrician for contraception counseling. She is newly sexually active. She recently lost 10 lbs and her BMI is now 32. She is otherwise healthy but has needle phobia. She has light periods and wants a method that will maintain little or no bleeding. However, her biggest concern is ensuring that her contraceptive will not cause weight gain. You counsel her that the best birth control method for her is:

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There is biologic plausibility that hormonal contraception could cause weight gain:
Estrogen could lead to increased fat deposition or mineralocorticoid activity resulting in fluid retention
Androgenic components of hormonal contraception could cause increased muscle mass or increased appetite from anabolic effects
BUT many studies have failed to demonstrate any significant weight gain attributable to contraception, perhaps excluding DMPA.
Numerous RCTs of OCPs show no clinically meaningful weight gain, but there is less info with progestin-only methods
Levonorgestrel IUD and etonogestrel implant have no effect on weight gain
In some specific populations (overweight and obese adults and adolescents), there can be some women who experience early and very significant weight gain on DMPA (though most patients do not have this side effect)
Copper IUD is not associated with weight gain, but blood loss increases by 30%
Levonorgestrel IUD is associated with more than 70% decrease in blood loss after the first few months of use. Amenorrhea rates are 20% at 1 year and 60% at 5 years

2. A 26 yo G1P1 is referred to you by her hematologist. She would like to get pregnant again in 2 years. She has a history of a DVT in pregnancy. She is otherwise healthy. She was diagnosed with chlamydia last week but has not started treatment. She wants to avoid DMPA because she heard it causes weight gain. She does not want anything that requires a pelvic exam. She has a busy job and has trouble remembering to take medication. The most appropriate birth control method is:

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Pregnancy leads to about a 1.4% incidence of venous thromboembolism (4-5X baseline risk)
Estrogen-containing contraception leads to a doubling of venous thromboembolism risk by increasing hepatic production of serum globulins involved in coagulation (factor VII, factor X and fibrinogen)
Some data suggest varying thrombotic risk with different progestins, but the main thrombotic effect is seen with estrogen
CDC Medical Eligibility Criteria rating for women with a history of DVT not on anti-coagulation: Category 4 (unacceptable health risks)
Implants/levonorgestrel IUD/Surgical sterilization: Category 2 (advantages generally outweigh risks)
Copper IUD: Category 1 (no restriction on use of this contraceptive for this patient)
Oral progestin-only contraceptives have a failure rate of 9%
ACOG recommends testing all patients with a prior DVT in pregnancy for antiphospholipid antibodies and inherited thrombophilias to help guide thromboprophylaxis

3. A patient presents to your office to be counseled regarding long-acting reversible contraception. In discussing the etonogestrel subdermal implant, you explain that the adverse effect most likely to lead to discontinuation of his method is:

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Potential adverse effects attributed to the contraceptive implant include mild insulin resistance, weight gain, headache, acne, change in bleeding patterns (including amenorrhea, irregular bleeding or frequent bleeding)
10-14% report worsening acne but only 1-4% discontinue use for this reason
20% experience amenorrhea (due to progestin effect of thinning endometrial lining over time)
Unlike DMPA (use > 2 years), the etonogestrel implant has no significant effect on bone mineral density
Weight gain may happen in some women but only 2-4% discontinue for this reason
Irregular bleeding = most common reason women discontinue etonogestrel implant (up to 11%).
More recent data: more than 50% request removal in the first 6 months because of irregular bleeding. Options for treatment of this include combined OCPs, NSAIDs, mifepristone + estradiol, mifepristone + doxycycline, or doxycycline alone. Improvement may be minimal. First line approach should be reassurance, though only ½ of patients with unfavorable bleeding patterns in the first 3 months have improvement over time