Emergency Postcoital Contraception

Recommended Methods
Combined Oral Contraceptives
Management of Gastrointestinal side Effects
Progestin Minipill
After 72 Hours


As a birth control option, emergency postcoital contraception is highly effective but underutilized. Its use could result in 1 million fewer abortions and 2 million fewer unintended pregnancies each year in the United States. Although 2 to 3 percent of women terminate a pregnancy each year through abortion, only 1 percent of women in America report using emergency contraception. It should be a primary prevention health service to women of childbearing age.


(1) Condom breakage or barrier method dislodged or torn during intercourse
(2) Refusal of a partner to use protection
(3) Exposure to possible teratogen, such as live vaccine, cytotoxic drug, etc.
(4) Forced sexual contact
(5) Missed contraceptive pills: It is theoretically riskier when missed at the beginning of a cycle and emergency contraception should be considered. Even though the risk is extremely low at the end of the menstrual cycle, a woman who has been raped or wants to avoid pregnancy for other reasons may want to employ emergency contraception. This is a legitimate use of the technique.

The probability of conception when emergency contraception should be considered is often unclear or misunderstood. the average fertile period for a woman lasts only six days per menstrual cycle and ends the day she ovulates. Unprotected sex three days before ovulation results in an estimated 15 percent pregnancy rate; one or two days before ovulation, about 12 percent. Sperm can survive in the female up to five days and the mature egg may be fertilized over a 24-hour period. The time period from ovulation to implantation is about seven days.

(1) Combined Oral Contraceptives: Uses estrogen-progestin combinations (ethinyl estradiol and norgestrel/levonorgestrel) - also known as the Yuzpe regimen after Albert Yuzpe, whose research on high-dose estrogen regimens led to the current treatment protocols. The efficacy of combined regimens that contain a progestin other than norgestrel/levonorgestrel has not been studied.
(2) The progestin-only minipill (levonorgestrel).
(3) The Copper-T 380 intrauterine device (IUD).
(4) Antiprogestins - Low doses of antiprogestin synthetic steroid RU 486 (mifepristone, Mifeprex) have been shown to be equally or more effective than existing oral regimens for postcoital contraception. However, these products are not readily available.

Combined Oral Contraceptives
The FDA has reviewed the data on the Yuzpe regimen and concluded that it is safe and effective. The American College of Obstetricians and Gynecologists also reviewed the date and made a special recommendation to its members that this regimen is underutilized and should be made more widely available to patients seeking reproductive health care.
Treatment: The regimen consists of 2 doses of ethinyl estradiol (100 ug) and levonorgestrel (0.5 mg). The first dose should be taken within 72 hours of unprotected intercourse and the second 12 hours after the first dose (see Table). It is equally effective whether initiated early or late within the 72-hour window. However, consider the timing of the second dose when administering the first. For example, a first dose at 3 in the afternoon will mean a second dose at 3 in the morning.
    The appropriate number of pills may be used from different trade name birth control pill packages. Recently, a prepackaged, dedicated product consisting of 4 pills (
PREVEN) has beenn developed.
     If 100 women have unprotected intercourse during the second and third week of their cycle, the probability is that eight will become pregnant. If the Yuzpe method is used, only two women will become pregnant (a 75% reduction).
Side effects: Mainly gastrointestinal: nausea 50%, vomiting 20%. Taking the pills with meals may reduce the risk of nausea, however, theoretically, this may lower plasma hormonal levels and reduce contraceptive efficacy.
     Less common side effects are heavy menses and mastalgia. Withdrawal bleeding occurs within three weeks of treatment. Thirty-eight percent bleed before their menstrual period is due. About 8% may be 4 or more days late.
Contraindications: Other than confirmed pregnancy, there are no absolute contraindications to the emergency use of oral contraceptive combinations. Studies have shown no evidence of harm to the developing fetus. Relative contraindications include migraine with marked neurologic symptoms and preexisting venous thromboembolic disease. Thrombotic episodes have been reported following use of this regimen. Although it is not clear where these events were actually related to hormone use, in these patients use of a progestin-only pill or emergency IUD insertion is recommended. If the timing of exposure makes the risk of pregnancy very slight, the safest course may be to do nothing at all.
     In England, where emergency contraception has been used in over 4 million cases in 13 years, no statistically significant increase in the rate of deep venous thrombosis has occurred.
Mechanism of action: Prevention or delaying of ovulation may be the primary mechanism of drug action. These hormones will not dislodge an implanted embryo. This is important to convey to patients because it has obvious significance to anyone whose religious beliefs prohibit interference with reproduction once fertilization has taken place. Those who remain fearful about hormonal side effects may prefer IUD insertion, or depending upon their likelihood of pregnancy, no treatment at all.
     Patients have not be shown to become dependent on this means of contraception. Also, the nausea associated with high dosages is significant enough to make them think twice about requesting this intervention on a regular basis.

Agents Used for Emergency Contraception
Ovral (white), Femenal
Norgestrel 0.50 + ethinyl estradiol 50 ug
Number of pills: 2

LoOvral (white)
Norgestrel 0.30 + ethinyl estradiol 30 ug
Number of pills: 4

Levlen (light orange), Nordette (light orange), Levora (white), Microgynon 30, Nordette, Rigevidon 21+7 (seven containing lactose)
Levonorgestrel 0.15 mg + ethinyl estradiol 30 ug
Number of pills: 4

Alese (pink)
Levonorgestrel 0.1 mg + ethinyl estradiol 20 ug
Number of pills: 5

Trilevlen (yellow), Triphasil (yellow), Tiivora (pink)
Levonorgestrel 0.1 mg + ethinyl estradiol 30 ug
Number of pills: 4

Orvette (yellow)
Norgestrel 0.075
Number of pills: 20

Dedicated Products
Preven: Per dose: 2 blue pills, 100 ug of ethinyl estradiol, 0.50 mg levonorgestrel.
Plan B: Per dose: 1 white pill, no ethinyl estradiol, 0.75 mg levonorgestrel.

No of doses: 2 (two)
Timing of administration: First dose within 72 hours of unprotected intercourse; second dose 12 hours later. The patient may wish to time her first dose as not to wake up during the night to take the second dose. Norgestrel contains two isomers, only one of which (levonorgestrel) is bioactive. Thus, 0.05 mg norgestrel is equivalent to 0.25 mg levonorgestrel.
(Red Brands: Philippine Oral Contraceptives)

Management of Gastrointestinal Side Effects of Emergency Contraceptive Medication
Nonprescription Drugs
Drug: Meclizine hydrochloride             
Dose:1-2 (25mg) tablets                          
Timing: 1 hr before first ECP dose; repeat if needed in 24 hr.

Diphenhydramine Hcl                
Dose: 1-2 (25mg) tablets                          
Timing: 1 hr before first ECP dose; repeat as needed q 4-6 hr.

Dose: 1-2 (50mg) tablets or 4-8 tsps       
Timing: 30 mins to 1 hr before 1st ECP dose; then q 4-6 hrs prn.

Cyclizine Hcl                              
Dose: 1 (50mg) tablet                               
Timing: 30 mins before 1st ECP dose; then repeat q 4-6 hrs prn.

Prescription Drugs
Drug: Meclizine Hcl                              
Dose: 1-2 (25mg) tablets                          
Timing: 1 hr before 1st ECP dose; repeat prn in 24 hrs.

Trimethobenzamide HCL           
Dose: 1 (250 mg) tablet  or 200mg suppository                            
Timing: 1 hr before first ECP dose; then prn q 6-8 hrs.

Promethazine Hcl                        
Dose: 1 (25mg) tablet or suppository                                 
Timing: 30 mins to 1 hr before 1st ECP dose; then prn q 8-12 hrs.           

Progestin Minipill
While somewhat less effective than combined preparations when used as a regular birth control method, the progestin-only minipill may outshine the former when it comes to emergency use. Not only is its efficacy thought to be greater, but nausea and vomiting are significantly less common, and it can be used even by women who cannot tolerate estrogen. The catch is that the required dosage of levonorgestrel, 0.75 mg may be unavailable in a single- or two-tablet format. In order to obtain postcoital protection, a woman must ingest two doses of 20 tablets each of norgestrel 12 hours apart, beginning within 72 hours of exposure. (Only half of the norgestrel pill consists of levonorgestrel; hence, the necessity for 20 tablets.) Faced with such an inconvenient and expensive regimen, most patients are willing to overlook the gastrointestinal effects associated with the combined preparations.

Copper T-380 A Intrauterine Device
The Copper-T IUD will prevent pregnancy up to five days following unprotected intercourse. Although not suitable for all women, the device is significantly more effective than either form of oral emergency contraception, reducing the risk of pregnancy by 99%.
Mechanism of action: Not firmly established, depending on the timing of insertion, may interfere with sperm transport or implantation. Because the method prevents implantation, an IUD may be inserted up to five days after the earliest estimated date of ovulation.
Side effects and risks are the same as those for IUD insertion at other times. If left in place, it will provide continuous effective contraception for up to 10 years. However, potential users should be carefully screened, as insertion may not be advisable in women who have elevated risk for PID or other sexually transmitted infections. Use is not recommended in women who have been raped, as they may have been exposed to sexually transmitted disease in the process. For women who are not at risk for STD, the health risks associated with IUD use are very low.
Contraindications: Confirmed or suspected pregnancy is a contraindication to the IUD, as presence of the device may cause spontaneous abortion, septic second-trimester abortion, or premature delivery.
Antiprogestins RU 486 (Mifepristone)
Mifepristone inhibits ovulation and blocks implantation by causing a delay in endometrial maturation. It causes an actual regression of the corpus luteum in 50 percent of women when given in the middle or late luteal phase. Only mifepristone is effective once implantation has occurred, actually interrupting an early pregnancy.
    In trials, RU 486, given as a single 600-mg dose within 72 hours after unprotected intercourse, was 100% effective as an emergency contraceptive. Other doses, 50 mg or 10 mg, given as a single dose within five days of unprotected sex were also effective in decreasing pregnancy rate by 85 %.
Dose: 10 mg, 50 mg, 600 mg
Timing of first dose after intercourse: 0 to 120 hours
Reported efficacy: 85 to 100% effective
Side effects: Less nausea and vomiting than the Yuzpe regimen. 18 % to 36 % of women experienced delay of menses of more than three days. The side effects were significantly related to the dose of RU 486 used.
After 72 Hours
What is the patient presents for care after 72 hours have passed, and the IUD is not an option? While we know that treatment efficacy does not drop to zero 73 or 74 hours after exposure, there obviously is a cutoff, somewhere around one week, beyond which an oral agent would be futile. Prior to that point, the decision of whether or not to proceed becomes a judgment call on the part of the patient and the physician. Although intervention may not succeed, it might be worth a try if the patient wants it, with the reassurance that no harm will be done is she becomes pregnant.

Like vaccine-preventable diseases, emergency contraception is an area of need in which, historically market forces have not provided sufficient impetus for new product development. This has remained the case despite encouragement from numerous professional organizations and even the FDA. Given the extensive societal costs of unplanned pregnancy, it seems logical for government agencies to step in at this point and offer appropriate incentives - such as liability protection - that could prompt pharmaceutical companies to address this important need. In the interim, physicians should inform patients about the availability of emergency contraception and consider prescribing or dispensing pill packs in advance, to give patients the option of initiating therapy with minimal fanfare.

Felicia Stewart (Hendry J. Kaiser Family Foundation) Hospital Practice. August 15, 1998
Randy Ellen Wetheimer, M.D. (Emergency Postcoital Contraception) American Family Physician
November 15, 2000 / Vol 62, Number 10; 2287-92.