Update on contraceptive options: A case-based discussion
ABSTRACTAs health care providers, we must engage our female patients in a dialogue about their contraceptive and fertility decisions. Empowering and educating our patients about their bodies’ hormones, the menstrual cycle, and the risk of unintended pregnancy are central to effective contraceptive counseling. Selecting an appropriate method for a patient and her medical profile is rewarding and challenging in view of new medications, novel delivery systems, and evolving research.
KEY POINTS
- Hormonal contraceptives have a number of noncontraceptive benefits, such as regulating the menstrual cycle.
- The Pearl index is the number of unintended pregnancies per 100 women per year. Rates are 15% using male condoms, 8% with oral contraceptives, 3% with depot medroxyprogesterone acetate (Depo-Provera) injections, and less than 1% with intrauterine devices or female or male sterilization.
- Estrogen-containing products should be avoided in patients with hypertension or who are at risk of venous thromboembolism.
CASE 3: FUTURE FERTILITY
A 30-year-old surgical resident who has never been pregnant comes for her annual examination. She currently desires birth control but would like to be pregnant 1 to 2 years from now. She has no history of significant medical illness. Her body mass index is 23 kg/m2, and she takes no medications. How do you counsel her?
Many options; also consider folic acid
Effective counseling leads to patient-centered decision-making for all treatments and procedures. Contraceptive counseling should elicit the patient’s perspective about hormonal methods and educate her on efficacy, proper use, and common adverse effects.
Contraception should fit the patient’s lifestyle. Questions as simple as “Are you a good pill-taker?” or “Are you comfortable with injections?” will help you and the patient assess what will work effectively and will maintain good adherence.
Deciding on a contraceptive option that is cost-effective is crucial, particularly for many young women or adolescents. Many oral contraceptives are widely available as generic formulations for less than $10 per month. Although generic drugs are not required to be 100% bioequivalent to their brand-name counterparts, they can provide a more economical option. For a complete guide to different hormonal contraceptive formulations, we suggest Choosing a birth control method, available on the Web site of the Association of Reproductive Health Professionals at www.arhp.org/upload-Docs/choosingqrg.pdf.12
As discussed earlier, half of all pregnancies are unplanned, and so women of childbearing age should be ingesting 400 μg of folic acid daily. Debate exists as to whether Americans who eat a balanced diet need a multivitamin.13 However, there is no debate about folic acid, which is proven to prevent neural tube defects. Newer formulations of ethinyl estradiol-drospirenone (Beyaz, Safyral) now contain an active form of folic acid (levomefolate calcium 451 mg in each pill). For the above patient who needs contraception and is willing to take birth control, the addition of folic acid provides an essential element in preconception counseling.
Regardless of the current contraceptive choice, patients who actively desire pregnancy should take a prenatal vitamin that contains folic acid and iron.
In addition to combined oral contraceptives, other options for this patient include medroxyprogesterone acetate (intramuscular or subcutaneous), NuvaRing, or intrauterine devices. The Ortho Evra patch is also an option for this patient. However, since 2008 the patch has carried an FDA warning that the risk of VTE is twice as high with this product than with oral contraceptives that contain 30 μg of ethinyl estradiol plus levonorgestrel.14 Postmarketing data did not show any higher risk of VTE in patch users compared with oral contraceptive users less than 40 years of age, however.15
CASE 4: PSYCHIATRIC ILLNESS
A 21-year-old woman who has bipolar II disorder comes to your office for her annual gynecologic evaluation. She has one sexual partner and desires oral contraceptive pills. Lithium treatment has failed for her, but her condition is stable on carbamazepine (Tegretol). She asks if it is true that women can still get pregnant while on the birth control pill. How do you counsel her?
Possible interactions with psychiatric drugs
Like the woman in case 3, this patient has many options, including estrogen-containing pills, the vaginal ring, the patch, injectable contraceptives, and intrauterine devices.
Certain antiepileptic, antipsychotic, or headache medications such as carbamezapine, phenytoin (Dilantin), oxcarbazepine (Trileptal), and topiramate (Topamax) decrease levels of hormonal contraceptives by induction of the CYP450 enzymes. Conversely, it is suggested that lamotrigine (Lamictal) levels decrease by up to 49% while patients concomitantly take oral contraceptive pills, which can induce seizure activity.16 Also, antibiotics such as rifampin (Rifadin) and even herbs such as St. John’s Wort can decrease the effectiveness of hormonal contraceptives by increasing their metabolism.
On the positive side, depot medroxyprogesterone acetate raises the seizure threshold by a mechanism attributed to high levels of progestins and is a better option for epileptic patients. A bulletin of the American College of Gynecologists addresses the paucity of data on hormonal treatments in depressed patients. However, some evidence points to slight improvement of depressive symptoms after 1 year in patients who took Depo-Provera compared with those who discontinued the drug.17
The Pearl index, a measure of contraceptive efficacy
We refer to the Pearl index when answering our patients’ questions about contraceptive efficacy. The Pearl index is defined as the number of unintended pregnancies per 100 women per year. The typical (or actual) effectiveness for each contraceptive method is quoted rather than the theoretical (perfect-use) efficacy.
We suggest simplifying this discussion with patients. For example, for every 100 women using male condoms for contraception, 15 women have unintended pregnancies per year. With hormonal contraceptives (pill, patch, or ring), for every 100 women there are 8 per year with unintended pregnancy, 3 of 100 with Depo-Provera, and less than 1 in 100 using intrauterine devices or female or male sterilization.18
Efficacy decreases (and the failure rate increases) with frequency of intercourse, irregular menstrual cycles, missed pills, improper dosing, and drug-drug interactions as described above.
