An international study on the acceptability of a once-a-month pill

Acceptability of different mechanisms of action of contraception in women: a questionnaire survey

BACKGROUND

The mechanism of action of a contraceptive method is an importantg consideration in a woman's choice of contraception. For the development of new methods of contraception it is important to understand the acceptability of different contraceptive mechanisms within a population.

METHODS

We recruited women attending contraceptive, termination of pregnancy or postnatal care services in Hong Kong for a questionnaire survey on their acceptability of the different ways in which contraceptive methods prevent pregnancy. Univariable and multivariable analyses were used to establish factors which may predict acceptability of the mechanism of action.

RESULTS

A total of 1448 women completed the survey. The acceptability of contraceptive methods that act by preventing fertilisation ranked highest (78%), followed by those that inhibit ovulation (52%), disrupt implantation (43%) and dislodge an implanted embryo (30%). A history of termination of pregnancy was associated with greater acceptance of all posited contraceptive mechanisms. There was a very low degree of agreement between the declared acceptance of the various contraceptive mechanisms and the ever use of a method with the respective mechanism of action (Cohen's kappa coefficient range 0.017-0.162).

CONCLUSIONS

In this population the acceptability of contraceptive methods that act by preventing fertilisation ranked highest, followed by those that inhibit ovulation, disrupt implantation and dislodge an implanted embryo. Women who had ever had a termination of pregnancy were more likely to accept all the posited contraceptive mechanisms.

Emergency contraception. Widely available and effective but disappointing as a public health intervention: a review

Emergency contraception (EC) prevents pregnancy after unprotected sex or contraceptive failure. Use of EC has increased markedly in countries where a product is available over the counter, yet barriers to availability and use remain. Although effective in clinical trials, it has not yet been possible to show a public health benefit of EC in terms of reduction of unintended pregnancy rates. Selective progesterone receptor modulators developed as emergency contraceptives offer better effectiveness than levonorgestrel, but still EC is less effective than use of ongoing regular contraception. Methods which inhibit ovulation whenever they are taken or which act after ovulation to prevent implantation and strategies to increase the uptake of effective ongoing contraception after EC use would prevent more pregnancies.

Toward developing a once-a-month pill: a double-blind, randomized, controlled trial of the effect of three single doses of mifepristone given at midcycle on the pattern of menstrual bleeding

OBJECTIVE

To test the feasibility of timing the administration of mifepristone as a once-a-month contraceptive pill on the 12th day before the next menses, as calculated from the length of the previous menstrual cycles.

DESIGN

Double-blind, randomized, controlled trial.

SETTING

Five family planning centers across the world.

PATIENT(S)

Three hundred ninety-nine women attending family planning clinics.

INTERVENTION(S)

Randomized to receive 10, 25, or 200 mg of mifepristone or a placebo.

MAIN OUTCOME MEASURE(S)

Lengthening or shortening of the normal menstrual cycle length following administration of the drug by at least 5 days.

RESULT(S)

The menstrual period came within 5 days of the predicted date in 88% of women receiving the placebo, 84% of women receiving 10 mg, 72% of women receiving 25 mg of mifepristone, and only 48% of women treated with 200 mg of mifepristone. Increasing the dose of mifepristone was associated with an increased chance of having a delayed period (P<.001). Only 45% of women were in the peri-ovulatory phase of the cycle according to LH and P measurements on the day of drug administration. Women treated before ovulation were more likely to have delayed menses with all three doses of mifepristone.

CONCLUSION(S)

Because of the disruption in cycle length, it appears unlikely that mifepristone administered once a month, at a calendar-based time, would provide a reliable method of contraception.

A single dose of mifepristone (200 mg) in the immediate preovulatory phase offers contraceptive potential without cycle disruption

A single dose of mifepristone is an effective emergency contraceptive and has potential as a regular "once-a-month" pill. If given in the early luteal phase, the formation of a secretory endometrium is inhibited or delayed and implantation of the embryo prevented. We have explored the effect of giving the mifepristone just prior to ovulation on the ovarian and endometrial cycle. Seven women with regular menstrual cycles were studied during a control cycle and then in a second cycle when 200 mg mifepristone was given within 24 h of ovulation, i.e., when luteinizing hormone (LH) in serum was >15 IU/L and the dominant follicle was >18 mm. Ovulation was confirmed within 48 h by ultrasound in five of the seven women. The remaining two women had luteinized unruptured follicle. Following mifepristone, menses occurred after a normal luteal phase compared to control cycle (13.7 +/- 0.7 vs. 13.7 +/- 0.9 days). In all subjects the endometrium on LH + 6 in the treatment cycle showed no, or very little, secretory changes, suggesting it was unlikely that pregnancy would have occurred. We conclude that mifepristone could be given as a "once-a-month" contraceptive pill without causing significant disruption in the menstrual cycle in the majority of women for a 4-day period from just prior to ovulation until LH + 3.

Amenorrhea associated with contraception-an international study on acceptability

Surveys undertaken in the 1970s and 1980s suggested that amenorrhea was unacceptable to most women, especially in developing countries. More recent research suggests that increasing numbers of women in the developed world prefer to menstruate less often. In a questionnaire survey of 1001 women attending family-planning clinics and 290 contraceptive providers in China, South Africa, Nigeria and Scotland, only among black women in Africa did the majority like having periods. In all other groups, most women disliked periods, which were "inconvenient" and associated with menstrual problems. Given the choice, the majority of Nigerian women would prefer to bleed monthly. Elsewhere, women would opt to bleed only once every 3 months, or not at all. In all except the Chinese centers, the majority of women would be willing to try a contraceptive which induced amenorrhea. Providers tended to overestimate the importance of regular menstruation to their clients. This is an important observation for scientists and funding agencies involved in developing new methods of contraception.

Noncompliance among a group of women using a novel method of contraception

OBJECTIVE

To compare the incidence of noncompliance measured objectively by a home use fertility monitor with the traditional self-reported incidence of compliance in a study of a new method of contraception.

DESIGN

Prospective cohort study.

SETTING

A large family planning clinic in Edinburgh.

PATIENT(S)

Thirty-two healthy women who took part in a trial assessing the efficacy of a novel method of contraception involving accurately timed administration of a single dose of mifepristone.

INTERVENTION(S)

Mifepristone was administered orally and a blood sample was collected on the same day.

MAIN OUTCOME MEASURE(S)

Percentage of missed tests detected by the monitor against the self-reported percentage during the critical period.

RESULT(S)

Women failed to perform 24.2% (95% confidence interval, 16.5-31.5) of the tests in the 162 cycles analyzed. They missed tests at an absolutely vital time for contraceptive efficacy in 42% of cycles according to the monitor while admitting to missing tests in 14.8%. Poor compliance was associated with younger women, those who discontinued the study before completion, and cycles in which women were not relying on the contraceptive method.

CONCLUSION(S)

The use of microelectronic monitoring systems may improve our understanding of the extent of patient noncompliance, providing objective information that no other monitoring technique can produce. This understanding provides the opportunity to make the optimum use of potentially effective treatments while validating research evidence.