Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis

BACKGROUND

Emergency contraception can prevent unintended pregnancies, but current methods are only effective if used as soon as possible after sexual intercourse and before ovulation. We compared the efficacy and safety of ulipristal acetate with levonorgestrel for emergency contraception.

METHODS

Women with regular menstrual cycles who presented to a participating family planning clinic requesting emergency contraception within 5 days of unprotected sexual intercourse were eligible for enrolment in this randomised, multicentre, non-inferiority trial. 2221 women were randomly assigned to receive a single, supervised dose of 30 mg ulipristal acetate (n=1104) or 1.5 mg levonorgestrel (n=1117) orally. Allocation was by block randomisation stratified by centre and time from unprotected sexual intercourse to treatment, with allocation concealment by identical opaque boxes labelled with a unique treatment number. Participants were masked to treatment assignment whereas investigators were not. Follow-up was done 5-7 days after expected onset of next menses. The primary endpoint was pregnancy rate in women who received emergency contraception within 72 h of unprotected sexual intercourse, with a non-inferiority margin of 1% point difference between groups (limit of 1.6 for odds ratio). Analysis was done on the efficacy-evaluable population, which excluded women lost to follow-up, those aged over 35 years, women with unknown follow-up pregnancy status, and those who had re-enrolled in the study. Additionally, we undertook a meta-analysis of our trial and an earlier study to assess the efficacy of ulipristal acetate compared with levonorgestrel. This trial is registered with ClinicalTrials.gov, number NCT00551616.

FINDINGS

In the efficacy-evaluable population, 1696 women received emergency contraception within 72 h of sexual intercourse (ulipristal acetate, n=844; levonorgestrel, n=852). There were 15 pregnancies in the ulipristal acetate group (1.8%, 95% CI 1.0-3.0) and 22 in the levonorgestrel group (2.6%, 1.7-3.9; odds ratio [OR] 0.68, 95% CI 0.35-1.31). In 203 women who received emergency contraception between 72 h and 120 h after sexual intercourse, there were three pregnancies, all of which were in the levonorgestrel group. The most frequent adverse event was headache (ulipristal acetate, 213 events [19.3%] in 1104 women; levonorgestrel, 211 events [18.9%] in 1117 women). Two serious adverse events were judged possibly related to use of emergency contraception; a case of dizziness in the ulipristal acetate group and a molar pregnancy in the levonorgestrel group. In the meta-analysis (0-72 h), there were 22 (1.4%) pregnancies in 1617 women in the ulipristal acetate group and 35 (2.2%) in 1625 women in the levonorgestrel group (OR 0.58, 0.33-0.99; p=0.046).

INTERPRETATION

Ulipristal acetate provides women and health-care providers with an effective alternative for emergency contraception that can be used up to 5 days after unprotected sexual intercourse.

FUNDING

HRA Pharma.

Ulipristal acetate taken 48-120 hours after intercourse for emergency contraception

OBJECTIVE

To evaluate the efficacy and safety of ulipristal acetate as emergency contraception in women presenting 48-120 hours after receiving ulipristal acetate for unprotected intercourse.

METHODS

Women aged 18 years or older with regular cycles who presented for emergency contraception 48 to 120 hours after unprotected intercourse were enrolled in 45 Planned Parenthood clinics and treated with a single dose of 30 mg ulipristal acetate. Pregnancy status was determined by high-sensitivity urinary human chorionic gonadotropin testing and return of menses.

RESULTS

A total of 1,241 women were evaluated for efficacy. Twenty-six were pregnant at follow-up, for a pregnancy rate of 2.1% (95% confidence interval 1.4-3.1%). These results satisfy the protocol-defined statistical criteria for success because the pregnancy rate was lower than both the estimated expected pregnancy rate and a predefined clinical irrelevance threshold. In addition, efficacy did not decrease over time: pregnancy rates were 2.3% (1.4-3.8%), 2.1% (1.0-4.1%), and 1.3% (0.1-4.8%) for intervals of 48 to 72 hours, more than 72 to 96 hours, and more than 96 to 120 hours, respectively. Adverse events were mainly mild or moderate, the most frequent being headache, nausea, and abdominal pain. Cycle length increased a mean of 2.8 days, whereas the duration of menstrual bleeding did not change.

CONCLUSION

Ulipristal acetate is effective and well-tolerated for emergency contraception 48-120 hours after unprotected intercourse.

LEVEL OF EVIDENCE

II.

Hormonal emergency contraception: a clinical primer

Unintended and teenage pregnancies are major public health concerns in the United States. Emergency contraception is used to prevent pregnancy after failure of a contraceptive method or after unprotected intercourse. Expanded use of emergency contraception has the potential to reduce unintended pregnancy and induced abortions, while reducing state and federal healthcare expenditures. The recent approval of Plan B as an over-the-counter medication for individuals over 18 years of age should improve access to this medication. However, there are still widespread misconceptions about the mechanisms and implications of emergency contraception. Expanded access to emergency contraception is associated with increased use, but not associated with decreased efficacy, increased sexual risk-taking behavior, or less consistent use of traditional birth control methods. This review is designed to provide clinicians with information regarding the use of emergency contraception for reproductive age patients. It includes a brief description of methods of use, mechanisms of action, and side effect profiles of the most commonly used methods of emergency contraception, levonorgestrel and the Yuzpe method.

Emergency contraception

Teen birth rates in the United States have declined during the last decade but remain much higher than rates in other developed countries. Reduction of unintended pregnancy during adolescence and the associated negative consequences of early pregnancy and early childbearing remain public health concerns. Emergency contraception has the potential to significantly reduce teen-pregnancy rates. This policy statement provides pediatricians with a review of emergency contraception, including a definition of emergency contraception, formulations and potential adverse effects, efficacy and mechanisms of action, typical use, and safety issues, including contraindications. This review includes teens' and young adults' reported knowledge and attitudes about hormonal emergency contraception and issues of access and availability. The American Academy of Pediatrics, as well as other professional organizations, supports over-the-counter availability of emergency contraception. In previous publications, the American Academy of Pediatrics has addressed the issues of adolescent pregnancy and other methods of contraception.

Differences between emergency contraception users in the United States and the United Kingdom

OBJECTIVES

to characterize emergency contraception (EC) users and clinical trial participants in the United States and the United Kingdom, comparing previous EC use and awareness, contraceptive history, and experience with EC.

METHODS

We collected data from all EC seekers (n=5383) at 1 US and 2 UK clinics (9/97-8/98). We also collected detailed information from women (n=2157) enrolling in an EC trial at the first 3 clinics and 2 additional UK sites (9/97-2/00).

RESULTS

More US (16%) than UK (4%) women reported additional acts (other than in the last 5 days) of unprotected sex during the cycle in which they sought EC. Fifty-eight percent of UK trial participants had used EC previously compared to 18% in the United States. Most participants in both groups used contraception regularly and reported needing EC because of condom breaks (67% and 56%). More UK than US participants used an ongoing method of contraception (38% v 28%). US women reported more side effects at follow-up than UK women did (76% v 59%), although similar proportions would take EC again or recommend it.

CONCLUSIONS

US and UK women in our trial experienced different side effects. Researchers should use caution when presenting aggregate results from international multicenter trials. In addition, readers should be aware that such aggregate results might mask important geographical differences. More research on experience with EC and barriers to contraceptive use in the United States is needed.

Emergency contraception

Emergency contraception is used to prevent pregnancy after a coital act not adequately protected by a regular method of contraception. In contrast to early medical abortion, emergency contraception prevents a pregnancy from starting and does not disrupt an established pregnancy. The most commonly used approaches consist of two oral doses of contraceptive steroids. The levonorgestrel-only regimen (levonorgestrel, 0.75 mg, repeated in 12 hours) appears to be more effective and better tolerated than the Yuzpe regimen (ethinyl estradiol, 100 microg, and levonorgestrel, 0.5 mg, repeated in 12 hours). In the largest randomized, controlled trial to date, levonorgestrel prevented about 85% of pregnancies that would have occurred without its use. Hormonal emergency contraception has no known medical contraindications, although it is not indicated for suspected or confirmed pregnancy. However, if hormonal emergency contraception is inadvertently taken in early pregnancy, neither the woman nor the fetus will be harmed. Nausea and vomiting associated with the Yuzpe regimen can be reduced by prophylactic use of meclizine. A strong medical and legal case exists for making hormonal emergency contraception available over the counter, as has happened in countries other than the United States. Easier access to and wider use of emergency contraception could dramatically lower the high rates of unintended pregnancy and induced abortion in the United States.

Hormonal emergency contraception

In the 1960s, high-dose estrogen was identified as a highly effective emergency contraceptive but was associated with a high frequency of nausea and vomiting. The combination of low-dose estrogen and a progestin (the Yuzpe regimen) is highly effective and much better tolerated. Recently, a progestin-only regimen containing levonorgestrel was found to be more effective than the Yuzpe regimen and caused significantly less nausea and vomiting. Danazol, an antigonadotropin, is well tolerated but has questionable efficacy Mifepristone has several pharmacologic actions that make it highly effective with an adverse-effect profile similar to that of the Yuzpe regimen. Progress has been made in the last 3 years toward increasing the number of emergency contraceptives that are accessible to women in the United States, and several highly effective options are available. The most effective and well-tolerated regimen available is levonorgestrel. However, the barriers to access and low patient and provider awareness limit the impact of emergency contraception on the rate of unintended pregnancies.

Emergency hormonal contraception: the community pharmacy perspective

OBJECTIVE

To explore the views of community pharmacists in the North West of England towards the deregulation of emergency hormonal contraception (EHC) and to examine their support and training needs.

DESIGN

Two focus group discussions.

SUBJECTS

Fourteen community pharmacists, of whom eight were currently participating in a scheme to supply EHC free of charge through a patient group direction (PGD).

RESULTS

A number of themes emerged from the discussions, which appeared to influence participants' views towards the use of EHC and towards deregulation. A number of participants appeared to lack detailed knowledge about the mode of action of EHC and misunderstandings about this, coupled with erroneously held beliefs about the adverse effects of the drug, appeared to influence their attitudes to deregulation. Participants identified risks associated with pharmacy supply of EHC, both to women and to themselves, in the form of litigation. EHC was accorded a special status which seemed to go beyond its pharmacological properties and risk-benefit profile. A key and recurring theme was abuse, an ill-defined concept which appeared to refer to multiple or repeated use. It is interesting to note that none of those participants supplying EHC under a PGD could provide any examples of such abuse from their own experience.

CONCLUSIONS

This small-scale study provides useful insights into the attitudes of these pharmacists towards EHC, the impact of increased availability of the drug, and the type of women who they believed would use EHC.

[Emergency contraception: a simple, safe, effective and economical method for preventing undesired pregnancy]

In the following article, the most recent knowledge on emergency contraception (EC) is reviewed. EC is defined as those contraceptive methods that may be used to prevent an unwanted pregnancy up to 3 days after unprotected intercourse, contraceptive failure or rape. In case of non-hormonal methods (IUD), the time window for pregnancy prevention goes up to 5 days after intercourse. The different regimens now available, hormonal and non-hormonal methods, indications, contraceptive effectiveness, side effects and safety profile, possible mechanisms of action and counseling strategies will be reviewed. The potential benefits on reproductive health of wide-spread knowledge and easy, non-restrictive access to this methodology are emphasized. An extensive list of recent references is enclosed.

The effects of self-administering emergency contraception

BACKGROUND

Emergency postcoital contraception prevents pregnancy, but it must be prescribed by a doctor and taken within 72 hours of intercourse. It has been proposed that emergency contraception be made available without a prescription. We undertook a study to learn how women might behave if given a supply of emergency contraceptive pills to keep at home.

METHODS

We assigned 553 women to be given a replaceable supply of hormonal emergency contraceptive pills to take home (the treatment group) and 530 women to use emergency contraception obtained by visiting a doctor (the control group). The frequency of use of emergency contraception, the use of other contraceptives, and the incidence of unwanted pregnancy were determined in both groups of women one year later.

RESULTS

The results for 549 women in the treatment group and 522 women in the control group were available for analysis. Three hundred seventy-nine of the women in the treatment group (69 percent) and 326 of the women in the control group (62 percent) contributed detailed information at follow-up. One hundred eighty of the women in the treatment group (47 percent) used emergency contraception at least once. Among those who returned the study questionnaire, 98 percent used emergency contraception correctly. There were no serious adverse effects. Eighty-seven women in the control group (27 percent) used emergency contraception at least once (P<0.001 for the comparison with the treatment group). The women in the treatment group were not more likely to use emergency contraception repeatedly. Their use of other methods of contraception was no different from that of the women in the control group. There were 18 unintended pregnancies in the treatment group and 25 in the control group (relative risk, 0.7; 95 percent confidence interval, 0.4 to 1.2).

CONCLUSIONS

Making emergency contraception more easily obtainable does no harm and may reduce the rate of unwanted pregnancies.

Hormonal postcoital contraception

Wide availability of hormonal postcoital contraception (HPC) is likely to reduce the incidence of unplanned pregnancies. The two most common indications for HPC are unprotected intercourse and 'condom accidents'. The combined estrogen/progestogen HPC described by Yuzpe is the most widely used method. It is given within 72 h of unprotected intercourse. The efficacy of combined HPC is high. The crude failure rate is 1-5 per 100 woman-months while the true reduction in pregnancy risk is over 75%. Efficacy is not influenced by the exposure-treatment interval within the 72-h 'window'. The mechanisms of action is multifocal and depends on the cycle phase at which treatment is instituted. Data are presented suggesting a consistent endometrial effect. None of the side-effects of HPC are serious. When HPC fails, there is so far no evidence of an adverse effect of the treatment on the outcome of pregnancy. Counselling should include all the above together with discussion of possible side-effects such as nausea and vomiting. The clinician should ensure that the woman uses an effective contraceptive thereafter. There is renewed interest in progestogen-only postcoital contraception. Varying doses of levonorgestrel have been used. The efficacy of some regimens is similar to that of the combined HPC. Danazol has not proved to be as effective. Antiprogestins hold the greatest promise of emergency contraception with high efficacy and low side-effects.

Emergency hormonal contraception usage in genitourinary medicine clinic attenders

OBJECTIVE

To assess the indications for usage of emergency hormonal contraception amongst a population of London genitourinary medicine clinic attenders.

METHODS

In a prospective study, 150 consecutive women receiving emergency hormonal contraception (EHC) were enrolled. The attending doctor completed a questionnaire of patient details and prescribed EHC with prophylactic prochlorperazine. Follow-up was arranged three weeks later, at which time outcomes and side-effects of therapy were recorded. For those women who did not reattended as planned case notes were reviewed at three months.

RESULTS

Of 150 women surveyed, 100 (66%) reported contraceptive method failure, 48 (32%) had used no contraception at the time of last sexual intercourse and two requested EHC after sexual assault. Ninety three (62%) reported condom failure, 7 (5%) oral contraceptive pill failure. Seventy five (50%) had used EHC before (range 1-10 times). Seventy one (47%) women reattended within three months. Five (3.3%) of the 150 women were pregnant; none of these cases had experienced nausea or vomiting whilst taking EHC. Side-effects were reported by 22 (31%) of the 71 patients who reattended. Nine (6%) women had been followed-up in the family planning advisory clinic. Of the 71 women who reattended, 39 (55%) reported that their preferred future method of contraception would be condoms. Of the 150 women 19 (13%) underwent tests for sexually transmissible infections within one month of presentation.

CONCLUSIONS

EHC usage in this population was associated with a failure rate of at least 3.3% and an overall side effect rate of 31%. Despite requests for emergency contraception because of condom failure many elected to continue using condoms as their preferred method of contraception. The majority of women (53%) did not return for follow-up or family planning advice, and so we believe that future contraceptive plans must be addressed at the time EHC is prescribed.

[Extrauterine pregnancy after hormonal postcoital contraception]

Postcoital contraception with estrogen-gestagen-combinations is a highly effective emergency measure in cases of unprotected sexual intercourse at midcycle. Pregnancies after hormonal postcoital contraception are rare and ectopic pregnancies are said to be an extreme rarity. At the Department of Obstetrics and Gynecology of the Philipps-University Marburg we could observe two women with ectopic pregnancies after administration of a ethinyestradiol-levonorgestrel combination (Tetragynon, Schering, Berlin). Both patients were operated by pelviscopy. We could not found a clear causal relationship between the administration of hormonal postcoital contraception and ectopic pregnancies, because both women had intrauterine operations in her history and therefore a certain level of tubal damage could not ruled out. Nevertheless, in cases of hormonal postcoital contraception a follow-up check after 3 weeks should be done and it should be kept in mind that ectopic pregnancies may occur, especially in patients with risk factors.

Mifepristone (RU 486) compared with high-dose estrogen and progestogen for emergency postcoital contraception

BACKGROUND

Mifepristone (RU 486) is a synthetic steroid with potent antiprogestational and antiglucocorticoid properties that provides an effective medical method of inducing abortion in early pregnancy. Since progesterone is essential for implantation, we tested the use of mifepristone for emergency postcoital contraception.

METHODS

We studied 800 women and adolescents requesting emergency postcoital contraception who had had unprotected intercourse within the preceding 72 hours. A total of 398 women and adolescents were randomly assigned to treatment with 100 micrograms of ethinyl estradiol and 1 mg of norgestrel, each given twice 12 hours apart (standard therapy), and 402 women and adolescents were randomly assigned to receive 600 mg of mifepristone.

RESULTS

None of the women and adolescents who received mifepristone became pregnant, as compared with four of those who received standard therapy; the difference in failure rates between the two regimens was not statistically significant. The number of pregnancies in each group was significantly lower than the number expected according to calculations based on the day of the cycle during which intercourse had taken place (P less than 0.001). In many subjects the stage of the cycle as calculated by menstrual history was inconsistent with measurements of plasma progesterone or urinary pregnanediol excretion. The subjects treated with mifepristone reported less nausea (40 percent vs. 60 percent) and vomiting (3 percent vs. 17 percent) on the day of treatment, as well as lower rates of other side effects, than the subjects treated with the standard regimen, but they were more likely to have a delay in the onset of the next menstrual period (42 percent vs. 13 percent).

CONCLUSIONS

Mifepristone is a highly effective postcoital contraceptive agent that, if used more widely, could help reduce the number of unplanned and unwanted pregnancies.

A multicenter clinical study on two types of levonorgestrel tablets administered for postcoital contraception

Contraceptive efficacy, cycle control and side effects of two types of 0.75 mg levonorgestrel tablets taken postcoitally during the periovulatory period of one cycle were studied in a multicenter trial involving 361 women. No significant differences were found between the two types of levonorgestrel pills in terms of contraceptive efficacy, cycle control and side effects. The failure rate observed (1.4% per treated cycle) was similar to that reported for other hormonal approaches to emergency postcoital contraception. Intermenstrual bleeding or spotting occurred in 11.5% of the cycles and anovulation as assessed from BBT charts in 14.4% of cycles. One or more side effects were reported by 22.2% of subjects. The relatively frequent occurrence of cycle disturbances and subjective side effects make it unlikely that the repeated postcoital use of levonorgestrel would be an acceptable routine method of contraception for most women.

Diethylstilboestrol--clinical pharmacology and alternatives in small animal practice

Diethylstilboestrol is currently only available in Australia for oral use in dogs and cats. As an orally and systemically active non-steroidal oestrogen, DES has been widely used in small animal veterinary medicine for a variety of indications. A review of the literature reveals that many of the recommendations for use are founded on anecdotal or unreported clinical observations. While many of the uses may be valid, accurate determinations of optimum dosing regimens have not been defined. This is especially unfortunate in view of the potential toxicity of DES to small animals. Nevertheless, particularly in cases of low-dose intermittent administration, oral DES appears indicated at least until data on alternative safe and effective interventions become available.

A neutrophilic reaction of Sweet's syndrome type associated with the oral contraceptive

A case is presented of a Sweet's syndrome-like eruption in association with the oral contraceptive. A 46 year old caucasian woman developed recurrent episodes of erythematous tender plaques on her trunk six weeks after commencement of the oral contraceptive (OC). Her condition clinically and histologically resembled Sweet's dermatosis. On cessation of the OC there was complete resolution of her lesions and she remains well 12 months later. This is the first report, to our knowledge, of a neutrophilic reaction to the oral contraceptive, and we believe that drugs may be implicated in the aetiology of atypical neutrophilic reactions simulating Sweet's syndrome in patients who are otherwise well.

Hormonal postcoital contraception with an ethinylestradiol-norgestrel combination and two danazol regimens

The ethinylestradiol-norgestrel combination (EE-NG) for postcoital contraception, as described by Yuzpe, has been shown to be an effective method but with frequent side effects. To overcome the problem of adverse effects a new approach using danazol was proposed, but the efficacy and acceptability of this treatment have not yet been tested in large studies. In a 5-year period at the AIECS Family Planning Centre in Milan we treated 2448 women requesting postcoital contraception using Yuzpe's regimen and two danazol regimens (800 mg/1200 mg). The patients' acceptability for danazol treatment was higher than for Yuzpe's regimen due to fewer, milder and shorter side effects. Nine pregnancies occurred in the EE-NG group (2.21%), 17 in the 800 mg group (1.71%) and 6 in the 1200 mg group (0.82%). Our study shows a statistically significant efficacy against expected pregnancy rates both with Yuzpe's regimen and with danazol. The 1200 mg danazol treatment seems to be more effective and can be considered a valid alternative to the EE-NG combination for hormonal postcoital contraception.

A comparative study of Norinyl 1/35 versus Lo-Ovral in Ile-Ife Nigeria

A comparative analysis of those women on Norinyl 1/35 versus those on Lo-Ovral showed those on Norinyl 1/35 were significantly (P less than or equal to 0.05) older than women in the Lo-Ovral group. There were no significant differences (P greater than or equal to 0.05) between the groups for other characteristics at admission. There were no significant differences (P greater than or equal to 0.05) between the groups at follow-up in the number of women reporting serious complications, menstrual complaints or other pill-related problems. The continuation rates at 12 months were 79.4 for the Norinyl 1/35 group and 76.7 for the Lo-Ovral groups. There were no pregnancies reported during the study period.

Postcoital contraception with dl-norgestrel/ethinyl estradiol combination: six years experience in a student medical clinic

Postcoital contraception with ethinyl estradiol/dl-norgestrel in combination has been available to women students attending the University of British Columbia since 1974. This paper reports on the side effects, cycle control and efficacy, for a six-year period (1979-1985). In this sample of women 50% reported side effects of nausea alone or nausea with vomiting. Length of the menstrual cycle was shortened in women who took the medication prior to the expected day of ovulation. The number of pregnancies reported was significantly (p less than 0.002) less than the number expected had the medication not been taken. Some women took the medication even though there was a possibility of conception earlier in the cycle and this might account for four of the failures. The mode of action of the postcoital medication remains unsolved making it difficult to understand possible reasons for the other 14 failures.

Postcoital contraception with levonorgestrel during the peri-ovulatory phase of the menstrual cycle. Task Force on Post-ovulatory Methods for Fertility Regulation

The contraceptive efficacy and side effects of postcoital levonorgestrel used repeatedly during the peri-ovulatory period of one cycle was examined in 259 women. All subjects were of proven fertility in their present union and had ovulatory cycles as assessed from pre-treatment BBT charts. The mean number of coital acts during the treatment cycle was 7.5 (SD:2.6) and the mean number of 0.75 mg levonorgestrel tablets taken during the peri-ovulatory period was 4.0 (SD:1.2). Two pregnancies, both considered to be method failures, occurred, giving a failure rate of 0.8% per treated cycle. Although the overall effect of levonorgestrel on menstrual cycle length was small and insignificant, menstrual cycle disturbances were not uncommon. Intermenstrual bleeding or spotting occurred in 8.5% of the treated cycles and 12.5% of the cycles were less than 20 or more than 35 days. Other side effects, mainly nausea, headache and dizziness, were reported by about 20% of the subjects but the apparent incidence of these complaints varied markedly between the nine participating centres from 0% to just over 50%. The data suggest that repeated postcoital use of levonorgestrel is probably not a viable approach to fertility regulation for the majority of women who have regular intercourse and wish to limit the number of their pregnancies.

Pregnancy prophylaxis: parenteral postcoital estrogen

A two-dose regimen of intravenous conjugated estrogen as a postcoital interceptive was studied retrospectively. One hundred eighteen women who presented themselves at the Louisville General Hospital emergency room with a history of involuntary intercourse received 50 mg of intravenous conjugated estrogen at the conclusion of their initial medical evaluation and a second 50-mg injection approximately 24 hours later. Three pregnancies occurred among the 92 women who were seen again 30 days or more after treatment. These women reported other episodes of unprotected intercourse in the treatment cycle. Twenty-six of the women treated were lost to follow-up. Complaints of side effects were uncommon. In this series, intravenous conjugated estrogen appears to have been acceptable management for women who had been raped if no other unprotected intercourse had taken place in the treatment cycle.

Interception II: postcoital low-dose estrogens and norgestrel combination in 633 women

The new low-dose hormonal postcoital method, a combination of 200 mcg ethinylestradiol and 2 mg norgestrel was used in 633 women, and a statistically significantly lower observed pregnancy rate was found compared to the expected number of pregnancies if no contraception was used. Patterns of menstruation, its onset and duration, after use of this morning-after pill, are documented in respect to follicular, midcycle and luteal administration. Individual side effects such as nausea, vomiting and mastalgia are noted, but antiemetics did not reduce the incidence. Though efficacy of this technique is not found to be favorable in comparison to the 5 mg ethinylestradiol treatment, the low-dose of steroid, the one-day treatment and its lesser side effects show this alternative morning-after pill suitable for use as a first choice in case of an unprotected sexual encounter.