Despite the availability of highly effective contraception, millions of unintended pregnancies still occur because of inconsistent, incorrect or non-use of oral contraceptives (~95% of unintended pregnancies) or failures of other methods of contraception (e.g., condom broke, diaphragm or cap dislodged, IUD expelled, use of less effective methods, such as fertility awareness or withdrawal). But I don’t want to dwell on the failures, rather I want to focus on the remedies by providing an update on emergency contraception based on an excellent review article by Elizabeth Raymond and Kelly Cleland published in the April 2, 2015 issue of the New England Journal of Medicine (NEJM).
Oral emergency contraception pills
There are two types of oral emergency contraception currently available in the U.S.:
- Ulipristal acetate (30 mg), an antiprogestin, requires a prescription in the U.S. but was recently approved for sale over-the-counter in Europe. Not all pharmacies carry it.
- Levonorgestrel (1.5 mg), a progestin, is available over-the-counter in many countries. It is marketed as Plan B One-Step, Take Action, Next Choice One-Dose, My Way as well as other generics
Both regimens work by delaying or inhibiting ovulation and are more effective and produce less nausea than older regimens that consisted of taking two birth control pills (a combination of estrogen and progesterone). The incidence of pregnancy 72 hours after sex was 1.4% in women who took ulipristal and 2.2% for levonorgestrel. Although some studies have suggested these pills may be less effective in women over 75 kg in weight, the European Medicines Agency has concluded that there is not enough data to conclude this with certainty. The FDA is currently conducting its own review of the issue.
Both pills are safe with only minor side effects being reported (headache, dysmenorrhea, nausea, and menstrual disturbances). Further, there have been no adverse effects on the conceptus if levonorgestrel is taken during pregnancy. And, the incidence of ectopic pregnancy was not greater than that in the general population.
Emergency oral contraceptive pills should be taken as soon as possible after unprotected sex. Ulipristal is said to be effective up to 120 hours after sex. Although levonorgestrel is effective for 4 to 5 days, the NEJM review states that it may be more effective the earlier it is taken.
Drug-drug interactions are assumed to be the same as those that affect birth control pills. Because ulipristal is an antiprogestin, it could interfere with the effectiveness of hormonal contraceptives, so it is recommended that women use a barrier method (diaphragm, condoms) according to these guidelines published in the NEJM article and adapted from “Emergency Contraceptive Pills: Medical and Service Delivery Guidelines,” 3rd edition:
- After taking levonorgestrel, start the hormonal method the same day or following day, but use a barrier method for the first 7 days; alternatively, start after the next menstrual period and use a barrier method in the interim
- After taking ulipristal, start the hormonal method after the next menstrual period and use a barrier method in the interim
- Before insertion of hormonal implants or the levonorgestrel-releasing intrauterine system, pregnancy should be ruled out
Randomized trials have failed to find an increase in the rates of unintended pregnancy or sexually transmitted diseases as a result of increased access to emergency contraception. However, some experts suggest that such access is unlikely to decrease the rate of unintended pregnancies either. Women are encouraged to initiate a reliable form of birth control if they want to avoid further unintended pregnancies.
Copper intrauterine device
The NEJM article states, “the most effective form of emergency contraception is the copper IUD.” This is because, in addition to serving as an emergency contraceptive after pregnancy has been ruled out, it can provide on-going protection for at least 10 years.
The problems with this approach are as follows
- It requires a professional to insert
- It is more costly than the pills (about $975 out-of-pocket compared to about $50 for the over-the-counter pills and $50 plus clinician/office fees)
- For up to 18% of women in one study, the insertion attempt was unsuccessful
- Some women have vaginal bleeding and cramping after insertion
According to the review article,
“Almost all women can safely use Copper IUD for emergency contraception; the only recognized contraindications are pregnancy, cancer of the genital tract, uterine malformation preventing device placement, copper allergy, mucupurulent cervicitis, current pelvic inflammatory disease, and known current cervical infection with chlamydia or gonorrhea.”
The big advantage the Copper IUD has over other forms of contraception is that once it is inserted, you are protected from unintended pregnancy for as long as it is in place. For women who got pregnant because, for whatever reason, they could not consistently take birth control pills as prescribed, this may well be the intervention of choice to prevent further unintended pregnancies.