Post-coital contraception using d1-norgestrel/ethinyl estradiol combination

Safety data for levonorgestrel, ulipristal acetate and Yuzpe regimens for emergency contraception

The World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) provide recommendations for use of emergency contraceptive pills (ECPs), including levonorgestrel (LNG) and combined oral contraceptives (COCs). A new ECP formulation, ulipristal acetate (UPA), is now available worldwide. To determine whether LNG, UPA or COC (Yuzpe) ECPs are safe for women with certain characteristics or medical conditions, we searched the PubMed and Cochrane databases for articles published from date of inception until May 2015 pertaining to the safety of LNG, UPA or Yuzpe ECP use. For direct evidence, we considered studies that looked at safety outcomes among women with certain medical conditions or characteristics taking ECPs compared with women not taking ECPs. For indirect evidence, we considered studies that reported pharmacokinetic (PK) data for ECP use among women with certain medical conditions or characteristics and studies that reported safety outcomes among healthy women taking ECPs. Five studies provided direct evidence; of these five studies, four examined LNG or Yuzpe use among pregnant or breastfeeding women, and one reported risk of ectopic pregnancy among women repeatedly using LNG ECPs. Poor pregnancy outcomes were rare among pregnant women who used LNG or Yuzpe ECPs during the conception cycle or early pregnancy. Breastfeeding outcomes did not differ between women exposed to LNG ECP and those unexposed, and there was no increased risk of ectopic pregnancy versus intrauterine pregnancy after repeated use of LNG ECPs compared with nonuse. Forty-five studies provided indirect evidence. One PK study demonstrated that LNG passes into breastmilk but in minimal quantities. In addition, nine studies examined pregnancy outcomes following ECP failure among healthy women, and 35 articles reported adverse events. Studies suggest that serious adverse events are rare among women taking any of these ECP formulations.

IMPLICATIONS

Evidence on safety of ECPs among women with characteristics or medical conditions listed within WHO and CDC family planning guidance is limited. However, both direct and indirect evidence for our study question did not suggest any special safety concerns for the use of ECPs among women with particular medical conditions or personal characteristics, such as pregnancy, lactation or frequent ECP use.

Pregnancy prevention using emergency contraception: efficacy, attitudes, and limitations to use

Emergency contraception, also called postcoital contraception, is the use of hormonal or mechanical methods to prevent pregnancy after an episode of unprotected intercourse. Although a number of methods of emergency contraception exist, its use in the United States is not widespread. This report reviews studies on the efficacy of hormonal methods of emergency contraception, as well as the literature on women's and physicians' knowledge of and attitudes toward this method of preventing pregnancy. Articles were selected for this review from a MEDLINE search using the term "postcoital contraception." These studies show that a variety of hormonal regimens are effective in reducing the chance of pregnancy when administered within 72 hours of an episode of unprotected intercourse. Failure rates range from 0%-4.66%, depending on the regimen and the study, although some controversy exists about how to calculate efficacy. Recent studies indicate that mifepristone (RU486) may be more effective than other methods, with fewer side effects. However, the more significant issue surrounding emergency contraception may be the reasons for its infrequent use in this country. A number of limitations to use have been identified in the literature, including lack of knowledge of the method among patients and physicians, inadequate counseling, and fears that widespread use of emergency contraceptives would lead to less consistent use of other methods of contraception.

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.

Levonorgestrel as a postcoital contraceptive

Time-release pellets of levonorgestrel (LNG), the progestogenic hormone contained in the contraceptive system Norplant, were implanted subdermally in mice, after the animals had mated and ovulated but before uterine implantation of embryos would have occurred, to examine whether the hormone could reduce the number of embryos that subsequently implanted and, if so, when it had to be administered in the postcoital period to achieve that effect. Hybrid female mice (C57BL x CBA) were paired with breeder males (CD-1) and LNG pellets were implanted on day 0, the day on which copulation plugs were found, or on day 2 or day 3 in the postcoital period. Mice in some groups were sacrificed on day 14 of the gestation period, and numbers of fetuses and/or resorption sites were counted, while mice in other groups were allowed to go to term. When LNG pellets were implanted subdermally on day 0 of the postcoital period, pellets designed to release 1.5 mg of hormone in 21 days failed to exhibit a contraceptive effect, but pellets designed to release 5 mg of hormone in 90 days were totally effective in preventing uterine implantation of embryos. Although the 5 mg pellets did not prevent embryos from implanting in all cases when administered on day 2, they prevented pregnancies from going to term by causing resorption of those embryos that did implant. When the pellets were implanted as late as day 3 in the postcoital period, uterine implantation of embryos occurred and fetuses were carried to term. Results of the study indicate that subdermal implants of LNG inserted postcoitally can prevent uterine implantation of embryos in mice, and thereby prevent pregnancy, despite fertilization of oocytes having occurred, if the hormone implants are inserted before day 3 of the postcoital period.

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.

Postcoital contraception: some characteristics of women who use this method

This paper describes some of the characteristics of the women who attended a medical clinic requesting postcoital contraception. The information is derived from 871 observations in 653 women who requested this contraception. The mean age of women at the time of first request for this method was older than expected (21.9 years) and the mean time from first coitus to first request for the method was longer than expected (2.7 years). Previous pregnancy with therapeutic abortion was reported by 11.3% of the women. Multiple users of the method were younger at their first visit, and more likely to report a previous pregnancy. The method of contraception used before and after the need for postcoital contraception tended to be the same. Barrier method users have need of this method either for use when they fail to use their barrier method or for use when their barrier method fails. The need for more general availability of this method is discussed.

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.

A comparison of high-dose estrogens versus low-dose ethinylestradiol and norgestrel combination in postcoital interception: a study in 493 women

Ethinylestradiol (EE), at a dosage of 5 mg/day for 5 consecutive days (5 mg EE), has generally been used for interception. A combination of 200 micrograms EE and 2 mg dl-norgestrel (EE + NG) was proposed as an effective alternative. Efficacy and tolerance of these methods were compared in a randomized, double-blind study. A group of 465 women was studied with a follow-up rate of 94.3%. In the 5 mg EE group a pregnancy rate of 0.9% was observed, and in the EE + NG group a rate of 0.4% was found. These rates differ significantly from the expected rates (P less than 0.0005, in both series). Nausea was noted in 59.1% of the 5 mg EE group and in 54.0% of the EE + NG series. Nausea and vomiting occurred in 20.8% and 15.8%, respectively. The efficacy of both methods as alternative morning-after medication was confirmed. The new method is preferable because treatment is limited to only 1 day.

Behavioural patterns in women requesting postcoital contraception

In a sample of women presenting for postcoital contraception in central London, two main categories of women were apparent. The first comprised those having regular intercourse: the majority of these had experienced a contraceptive method failure. Many of the second category had used no contraceptive; they were often having intercourse for the first or second time with a new partner, for the first time after an interval with an existing partner or for the first time ever. Many women had experienced difficulty in finding out where they could be treated but were persistent in their efforts to obtain the necessary expert advice. Almost all had used contraception in the past. Acceptance of a contraceptive method for future use was high.

Mode of action of dl-norgestrel and ethinylestradiol combination in postcoital contraception. II. Effect of postovulatory administration on ovarian function and endometrium

A combination of 1.0 mg dl-norgestrel and 0.1 mg ethinylestradiol (EE) was administered orally at 36 hours after the detection of the luteinizing hormone peak and again at 48 hours in 12 healthy volunteers with normal menstrual cycles. The effects on ovarian function were studied by comparing the daily serum levels of progesterone (P), 17 alpha-hydroxyprogesterone, and estradiol (E2) in control (placebo) and treatment cycles. Five subjects showed no significant change in the levels of these steroids but had a shortened luteal phase. The treatment significantly decreased both P and E2 levels in three subjects, while two subjects showed diminished E2 levels only. The remaining two subjects had lower P levels and fluctuating E2 patterns. Endometrial biopsies from both study cycles indicated asynchronous development of the epithelial and stromal components in the treatment cycle. These findings (abnormal luteal phase steroid levels and duration and outphased endometrial development) indicate that corpus luteum function was variously affected by the action of norgestrel-EE treatment.

Side effects of danazol compared with an ethinyloestradiol/norgestrel combination when used for postcoital contraception

A postcoital contraceptive with a lower incidence of nausea and vomiting than oestrogen-progestogen combinations would be a significant advance. During a nine-month period, 101 women were treated at the Margaret Pyke Centre in London with either an oestrogen-progestogen combination or with danazol. A comparison of the side effects of each drug is reported. Those treated with danazol were six times less likely to experience nausea and none vomited. With the exception of breast symptoms, other side effects were five times less common in women receiving danazol. These differences give danazol a clear advantage in terms of patient acceptability. Further experience will enable the efficacy of danazol to be evaluated and so determine whether this drug should become the preferred hormonal postcoital treatment.

A multicenter clinical investigation employing ethinyl estradiol combined with dl-norgestrel as postcoital contraceptive agent

Six hundred ninety-two women were enrolled in a multicenter clinical trial to evaluate a combination of ethinyl estradiol and dl-norgestrel as a postcoital contraceptive. When compared with various formulas predicting the probability of pregnancy in this group, the number of pregnancies observed appears to be reduced by approximately 84%. The combination of 200 micrograms of ethinyl estradiol and 2 mg of dl-norgestrel seems to be effective as a postcoital contraceptive with several advantages over estrogens alone.

Postcoital contraception

The evolution of postcoital contraception has led to the development of emergency measures to be used following a single unprotected act of intercourse and to ongoing methods, such as the administration of a contraceptive steroid agent following every coital exposure. In emergency situations, the most commonly employed hormonal steroids are the synthetic, conjugated and natural estrogens, administered in large doses for five days. Recently, a combination of an estrogen and a progestin has been employed for the same purpose. A copper-bearing intrauterine device (IUD), inserted within seven days of coitus, has also been utilized with success. Progestins alone have been utilized as an ongoing method of postcoital contraception. Failure rates have been found to vary with the dosage, the specific progestin employed and the frequency of intercourse. The major role of postcoital contraception in the developed world appears to be as an emergency measure. Ease of availability, a high degree of efficacy and a low incidence of side effects are essential for patient and physician acceptance.

Mode of action of DL-norgestrel and ethinylestradiol combination in postcoital contraception

Possible mechanisms of action of a combination of ethinylestradiol (EE) and dl-norgestrel as a postcoital contraceptive agent were studied in 12 healthy female volunteers. An oral dose of 0.1 mg of EE and 1.0 mg of dl-norgestrel was given at the predicted time of ovulation and again 12 hours later. Serum luteinizing hormone, prolactin, progesterone, 17 alpha-hydroxyprogesterone, and estradiol were measured by specific radioimmunoassays in blood samples obtained daily from the 8th day of the menstrual cycle to the 1st day of menses. Hormone profiles suggested that the medication elicited a range of individual variations in pituitary and/or ovarian responses. Histologic examination of the endometrium consistently showed significant alteration in endometrial development with a dissociation in maturation of glandular and stomal components. This postcoital contraceptive acts either by (1) suppressing ovulation or (2) disrupting luteal function by acting directly on the corpus luteum or by interfering with appropriate endometrial responses to ovarian steroids.