Your search found 16 Results

  1. 1
    Peer Reviewed

    Comparison of three single doses of mifepristone as emergency contraception: a randomised controlled trial.

    Jin J; Weisberg E; Fraser IS

    Australian and New Zealand Journal of Obstetrics and Gynaecology. 2005 Dec; 45(6):489-494.

    This is an analysis of the Australian component of a large World Health Organization multicentre dose-finding study of mifepristone for emergency contraception and the first clinical study of this controversial drug in Australia. The aims were to compare the effectiveness and side-effects of three single doses of mifepristone taken within 120 h after unprotected coitus as emergency contraception. Design: Double-blind, randomised controlled trial. One hundred fifty healthy women with regular menstrual cycles who requested emergency contraception. Participants were allocated randomly to one of the three doses (10, 50 and 600 mg). The primary outcome was confirmed pregnancy, and secondary outcome measures included side-effects and delay in the onset of the next menses. Pregnancy rates for mifepristone 10, 50 and 600 mg were 2.0, 2.1 and 2.1%, respectively, with no significant difference between groups. No major side-effects occurred, except an unpredictable delay in the onset of the next menses. Mifepristone 600 mg caused a significantly longer delay in the onset of the next menses than either the 10 or the 50 mg dose. Lowering the dose of mifepristone from 600 to 10 mg did not significantly impair its effectiveness as an emergency contraceptive, and caused less delay in the onset of the next menses. Therefore, a dose as low as 10 mg may be preferable to 600 mg for emergency contraception. This is very much lower than the dose required to terminate a pregnancy. (author's)
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  2. 2
    Peer Reviewed

    Ruling out pregnancy among family planning clients: the impact of a checklist in three countries.

    Stanback J; Diabate F; Dieng T; de Morales TD; Cummings S

    Studies in Family Planning. 2005 Dec; 36(4):311-315.

    Women in many countries are often denied vital family planning services if they are not menstruating when they present at clinics, for fear that they might be pregnant. A simple checklist based on criteria approved by the World Health Organization has been developed to help providers rule out pregnancy among such clients, but its use is not yet widespread. Researchers in Guatemala, Mali, and Senegal conducted operations research to determine whether a simple, replicable introduction of this checklist improved access to contraceptive services by reducing the proportion of clients denied services. From 2001 to 2003, sociodemographic and service data were collected from 4,823 women from 16 clinics in three countries. In each clinic, data were collected prior to introduction of the checklist and again three to six weeks after the intervention. Among new family planning clients, denial of the desired method due to menstrual status decreased significantly from 16 percent to 2 percent in Guatemala and from 11 percent to 6 percent in Senegal. Multivariate analyses and bivariate analyses of changes within subgroups of nonmenstruating clients confirmed and reinforced these statistically significant findings. In Mali, denial rates were essentially unchanged, but they were low from the start. Where denial of services to nonmenstruating family planning clients was a problem, introduction of the pregnancy checklist significantly reduced denial rates. This simple, inexpensive job aid improves women's access to essential family planning services. (author's)
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  3. 3

    Neuroendocrinology and reproduction in the human.

    World Health Organization [WHO]. Scientific Group

    Geneva, Switzerland, WHO, 1965. 19 p. (WHO Technical Report Series No. 304)

    This WHO technical report focuses on the 1) psychosomatic factors in human reproduction; 2) hypothalamo-hypophyseal system; 3) mechanism of sexual rhythm; 4) nervous influences on the hypothalamus; 5) hormonal influences on the hypothalamus; 6) neuroendocrine aspects of sexual behavior; and 7) effects of drugs on reproduction. After summarizing current research status on the above-mentioned topics, the following research needs are suggested: 1) assays of individual human endogenous gonadotropins, suitable for clinical application; 2) autoradiography, fluorescent-antibody, spectrophometric interference and histochemical and biochemical techniques for studying cells that supply axons to the primary capillary plexus of the hypophyseal portal system and for studying effects of different hormonal status on hypothalmic structure and function; 3) computer techniques for evaluating electrophysiological data; 4) improved lesioning techniques; 5) comparative studies of reproductive activity patterns, exteroceptive factors, neuroendocrine factors in sexual and related social behavior, and long-term or delayed effects of drugs administered during gestation on subsequent sexual development; 6) studies of synaptic connections of hypothalamic neurones; 7) studies of endogenous gonadal and gonadotropin production in prepuberal animals; 8) functional significance of regional distribution of hypophyseal portal system; 9) mechanisms involved in selective uptake of labeled hormones; 10) hypothalamic lesions in species with spontaneous ovulation and active luteal function; 11) direct effect of gonadal hormones on single hypothalamic neurones studied with combination of microinjection and unit recording devices; 12) studies of the possibility of a direct feedback of gonadotropic hormones on the hypothalamus; 13) studies of the receptor mechanisms involved in neuroendocrine reflexes; 14) wider exploration of brain structures, with regard to feedback action of gonadal hormones; 15) studies of pineal function; 16) further investigation of a possible role of the peripheral autonomic pathways in reproductive processes; and 17) research on the application of tissue culture techniques for studying problems of the origin and metabolic effects of neurohormonal mediators and the biochemcial and morphological changes induced by sex hormones.
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  4. 4

    Ring, monthly injectable produce less menstrual disruption than DMPA.

    Klitsch M

    International Family Planning Perspectives. 1992 Jun; 18(2):75-7.

    The main points of a study from the WHO Special Program of Research, Development and Research and Training in Human Reproduction on menstrual bleeding patterns and contraceptive use are presented. 1875 users of oral contraceptives, 1822 users of monthly injectables, 546 users of vaginal rings, and 1109 depot-medroxyprogesterone acetate (DMPA) users kept diaries of full bleeding and days of spotting during the 1st year a method was started. This information was compared with data from the 1930s and 1960s on bleeding patterns among nonusers of contraceptive methods. Monthly data were excluded in which pregnancy occurred of following a pregnancy, and when there were menstrual disorders or gynecological surgery. Data were then limited to women aged 18-34 years which left 3893 woman years of menstrual cycles. The results revealed that women who used hormonal contraceptives such as the vaginal ring or monthly injectables tended to have shorter periods of menstrual bleeding and more regular predictable periods than women on longterm injectables. Most women have variable bleeding patterns during the year, even when not using hormonal methods. Nonusers, pill users, and vaginal ring users had a median of just more than 3 bleeding or spotting day episodes during a 90-day period vs. 3 days among injectable users and <2 days for DMPA users. However, when the average duration of bleeding or spotting episodes was examined, the median was 4 days for pill users, 5 days for vaginal ring users, and 6 days for DMPA users. Menstrual cycle average length was lowest at 26 days for vaginal ring users, 28 days for nonusers, 29 days for injectable users, and 36 days for DMPA users. The median value for difference between the longest and the shortest cycle within 12 months was around 10 days for nonusers and pill users and 24 days for injectable or vaginal ring users vs. 55 days for DMPA users. The median for the longest episode of bleeding or spotting was 5 days for pill users, 7 days among nonusers, monthly injectable users, or vaginal ring users, and 12 days among DMPA users, of which 25% bled for at least 21 days and 1 in 29 bled for 55 days or more. The shortest bleeding-free intervals was the median for vaginal ring users at 21 days, and longest for DMPA users at 27 days. Other methods were similar to the intervals for the vaginal ring. 25% of DMPA users had a minimum bleeding-free interval of only 2 days, and 25% had an interval of at least 20 days. The myth is debunked that normal women have normal and regular cycles of 25-35 days.
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  5. 5

    Safety of IUDs [letter]

    McCowan L

    NEW ZEALAND MEDICAL JOURNAL. 1987 Aug 12; 100(829):503.

    In 1987, the Minister of Health of New Zealand called for a committee to examine standards for IUDs, set guidelines for packaging information, consider reports of adverse reactions, and request information on IUD usage from users, physicians, and manufacturers. The media presented the committee's purpose and concerns in such a way, however, that coverage caused anxiety and uncertainty among women using IUDs. The family planning and medical communities needed to reassure those women with an IUD and who have had no problems of the IUD's safety. A 1987 WHO report could assist these communities because it attested to its effectiveness and safety for some women. For example, it referred to a Women's Health Study in the United States and WHO studies that showed that current IUD users are not at any higher risk of ectopic pregnancy than are those women who do not use any contraception. The report also stated that uterine perforation occurs <1/2000 insertions. In addition, it referred to evidence that fertility returns immediately after removing the IUD. The report concluded that the IUD is an important method of fertility regulation with high continuation rates and significant advantage in convenience of use. On the other hand, it also concluded that some women should never have an IUD, such as those who have invasive cancer of the cervix or uterus, a suspected pregnancy, or active pelvic infection. It further pointed out contraindications which included nulliparity, past ectopic pregnancy, anemia, heavy menstrual bleeding, previous pelvic inflammatory disease, an abnormally shaped uterus, etc. Women must always have the right to select from a range of contraceptives, including the IUD, and make an informed decision as to which method is best for her needs.
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  6. 6
    Peer Reviewed

    The analysis of menstrual bleeding patterns: a review.

    Belsey EM; Farley TM

    CONTRACEPTION. 1988 Aug; 38(2):129-56.

    Methods of analyzing vaginal bleeding patterns, both of normally menstruating non-contracepting and contracepting women, are reviewed, and the reference period method is described in greater detail. For women using long-acting hormonal methods, the concept of cycle is no longer appropriate. The reference period method adopts the woman as the unit of analysis, divides her menstrual diary into consecutive periods, and summarizes vaginal bleeding patterns within each period. Data are presented in bar plots showing median length of bleeding, 5th and 95th percentiles, means and standard deviations. Natural, oral contraceptive, and IUD patterns are similar, while 3-monthly injections, vaginal rings and minipill patterns are disrupted patterns with no notion of cyclicity. Dealing with events that overlap reference period boundaries is still a problem, and is still being studied by working groups, in particular at WHO and the University of Exeter. For example, the effects of different definitions have not yet been systematically evaluated, and recommendations have not been tested empirically. The WHO has published a set of data on 4817 women's diaries to stimulate statistical research on this topic.
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  7. 7
    Peer Reviewed

    A micro-computer software for the analysis of menstrual diaries: the menstrual diary system.

    Pinol A; Machin D

    CONTRACEPTION. 1988 Aug; 38(2):157-63.

    A microcomputer software program called the Menstrual Diary System (MDS) is described which analyzes menstrual diaries by the reference period method, according to WHO guidelines. An IBM compatible microcomputer with floppy or hard disk, at least 256K of memory, and an MS-DOS 2.0 or later operating system is used. Menstrual data consist of entries labeling vaginal bleeding as absent, bleeding or spotting. There are optional parameters for the drive, path, and printer used by the system; user-defined symbols for bleeding patterns; screen characteristics; file management by date and length of data collection (maximum 380 days); and subject identifying information. A data management section permits data entry. The data analysis section follows the reference period method, allowing for within-subject analysis and between-subject analysis. Diary data entered in MDS can be transferred onto standard ASCII file to be used by other packages. Examples of output are provided.
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  8. 8

    Why menstruate?

    Short RV

    Healthright. 1985 Aug; 4(4):9-12.

    The pattern of reproductive activity displayed by early hunter-gatherer ancestors, before the dawn of civilization, must have been vastly different from today's pattern. In the absence of contraception such women would have spent the greater part of their reproductive lives either pregnant or in lactational amenorrhea. In developing these ideas further it was estimated that a hunter-gatherer woman would have spent about 15 years in lactational amenorrhea, whereas just under 4 years would have been occupied by her 5 pregnancies, and she would only have had about 4 years of menstrual cycles. The total number of menstrual cycles she would experience in her entire life would be no more than about 50. This is in marked contrast to the situation today in a typical Western woman using contraceptives and experiencing menarche at 13 and the menopause at 50. Allowing her 2 years' respite from cycles during her 2 pregnancies, each followed by only a token period of breastfeeding, this leaves 35 years during which she would experience about 420 menstrual cycles. The conclusion is that an excessive number of menstrual cycles is an iatrogenic disorder of communities practicing any form of contraception. Thus, it is important to note that even the condom or vasectomy have important repercussions on the female's reproductive cycle. Since 99.9% of human existence has been spent living a nomadic hunter-gatherer life, this high frequency of menstrual cycles is a new experience, one that humans may be genetically ill-adapted to cope with. In fact, there are a number of "diseases of nulliparity" whose incidence is markedly increased in women with few or no children and who are therefore experiencing an increased number of menstrual cycles. These diseases include carcinoma of the breast, endometrium and ovaries, and endometriosis. As part of the effort to develop contraceptives that promote a healthy state of fertility, it is necessary to ask the question, "is a period really necessary?" To learn if women women accept a contraceptive method that reduced the frequency of menstruation, a clinical trial of an oral contraceptive was conducted. The OC was administered in such a way as to produce a withdrawal bleed only once every 3 months. This was termed the tricycle pill regimen. 196 women attending a family planning clinic in Edinburgh, Scotland, volunteered to participate, although 89 of them subsequently withdrew from the trial for a variety of reasons before it was completed at the end of a year. Overall, 82% of the women positvely welcomed the reduction in the number of periods; 91% of the women who completed the trial even refused to revert to a standard monthly OC regimen thereafter. The findings were in complete contrast to the results of a World Health Organization survey of patterns and perceptions of menstruation. But the WHO sample was highly biased in favor of women having regular menstrual cycles, and hence quite unrepresentative of the population as a whole. In sum, even the most pessimistic estimate of the WHO's menstruation survey shows that a proportion of women in every country investigated were prepared to accept amenorhea as a by-product of contraception. Reversible amenorrhea might become an increasingly popular form of contraception, and it might also confer significant health benefits.
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  9. 9

    Need for and acceptability of long-acting steroidal contraception.

    Shain RN; Potts M

    In: Zatuchni GL, Goldsmith A, Shelton JD, Sciarra JJ, ed. Long-acting contraceptive delivery systems. Philadelphia, Pa., Harper and Row, 1984. 1-19. (PARFR Series on Fertility Regulation)

    Depo-Provera (depomedroxy-progesterone acetate, or DMPA) and NORPLANT (the Population Council's registered trade name for subdermal implants) are focused on in this literature review. Over the past 17 years, more than 1 million individual doses of Depo-Provera have been supplied in Thailand. Currently 6,000 women a month use the method. Depo-Provera has proved outstandingly successful in Bangladesh for years. The basic disadvantage of long-acting steroid systems is that return to fertility is slow and unpredictable. Other disadvantages include menstrual distrubances and weight gain. Acceptability of injectable contraceptives has been studied primarily by the World Health Organization (WHO). In 1976, the Task Force on Acceptability of Research and Family Planning explored preferences among 3 routes of contraceptive administration: 1)oral; 2)intravaginal; and 3)injection. The study was conducted in Indonesia, Korea, Pakistan, and Thailand. Although the oral route was generally preferred by most women, many respondents still chose the injectable. A WHO III multicentered trial comparing the use, effectiveness, side effects and bleeding patterns of Depo-Provera and norethisterone enanthate (NET-EN) was terminated after only 1 year because of excessively high pregnancy rates with NET-EN. A total sample of about 250 women in Manila and Alexandria were interviewed. Results indicated that the 2 most important considerations were effectiveness and menstrual bleeding. Depo-Provera did not affect menstruation. Various types of subdermal implants releasing a contraceptive Silastic implant, is placed beneath the skin of the forearm or upper arm and provides 5 or more years' protection against pregnancy. The 6 capsules are not biodegradable and require surgical removal under local anesthesia.
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  10. 10
    Peer Reviewed

    Multinational comparative clinical evaluation of two long-acting injectable contraceptive steroids: norethisterone oenanthate and medroxyprogesterone acetate: 2. bleeding patterns and side effects.

    World Health Organization [WHO]. Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Long-Acting Systemic Agents for Fertility Regulation

    Contraception. 1978 May; 17(5):395-406.

    A WHO sponsored comparative trail (9 centers) studied the bleeding patterns and side effects experienced by 1678 women using injectable (every 12 weeks) norethisterone enanthate (NOR) and depot-medroxyprogesterone (DMPA). 388.8 women-years of menstrual experience with NOR and 372.5 with DMPA were studied. The percentage of women with total amenorrhea with DMPA was significantly higher than with NOR for all injection intervals. The porportion of women with total amenorrhea increased significantly over time with both drugs (chi-square=33.9 for NOR and 73.4 for DMPA; P < .001). After 1 year, 35% of DMPA and 8.6% of NOR users had total amenorrhea. With NOR, the cycle length distribution changed markedly over time, with the percentage of short cycles under 25 days diminishing as the percentage of long cycles in excess of 46 days increased. In contrast, DMPA held cycle length patterns more or less constant. Length of bleeding and spotting episodes were significantly greater with DMPA. The mean number of bleeding/spotting days decreased over time with both drugs; the difference from the 1st to 4th injection was statistically significant (P < .001). Though the overwhelming majority of women experienced abnormal cycles with both drugs, the percentage of normal cycles remained fairly constant during consecutive intervals. Headache was the most frequently reported complaint: 10.7% of DMPA and 6.9% of NOR users. Other nonmenstrual side effects were reported with similar frequencies in both groups.
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  11. 11

    Hormonal changes in the menstrual cycle.


    In: Diczfalusy, E., ed. Regulation of human fertility. (Proceedings of the WHO Symposium on Advances in Fertility Regulation, Moscow, USSR, November 16-19, 1976) Copenhagan, Denmark, Scriptor, 1977. p. 21-71

    This chapter reviews the hormonal changes which occur during the menstrual cycle. During the last days of the preceeding menstrual cycle, plasma levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) increase. Follicular phase is characterized by gradually increasing estrogens. A few days preceding the LH surge, some little understood changes in estradiol, LH, and 17-hydroxyprogesterone, on one hand, and ACTH, cortisol, and aldosterone, on the other, occur. Evidence indicates that the estradiol peak occurs first, followed by a simultaneous rise and fall in LH and 17-hydroxyprogesterone values. The peak period of LH is about 32-44 hours long, during which time a rise in progesterone levels takes place. Other pituitary and steroid hormones (human chorionic gonadotropin, ACTH, prolactin, testosterine, androstenedione, cortisol, and aldosterone) show elevated levels during the periovulatory period. Ovulation occurs 16-48 hours after LH peak. The period following LH surge is characterized by rapidly increasing levels of progesterone, 17-hydroxyprogesterone, and 20-alpha-dihydroprogesterone, accompanied by moderately increasing estrogen levels to form the typical luteal-phase hormonal pattern. A luteal increase occurs also in levels of several other hormones, ranging from renin activity to angiotension, or from pregninolone to aldosterone. The last part of the luteal phase is characterized by rapidly declining levels of peripheral hormones. The perimenstrual phase around onset of heavy bleeding is characterized by gradually decreasing levels of progesterone, 20-alpha-hydroprogesterone, estradiol, and testosterone, associated with an incipient rise in LH and FSH levels.
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  12. 12

    Comparison of IPCS and Copper-7 bleeding patterns during the first 12 months of use.


    In: Mishell, D.R., Jr., and Martinez-Manautou, J., eds. Clinical experience with the progesterone uterine therapeutic system. (Proceedings of the Acapulco Workshop, Acapulco, Mexico, October 15-16, 1976) Princeton, New Jersey, Excerpta Medica, 1978. p. 99-103

    In order to compare the efficacy and acceptability of the Progestasert progesterone-releasing IUD and the Gravigard Copper-7 device, 295 parous women randomly received the progesterone device (146) or the copper device (149). Follow-up examinations took place at 1, 3, 6, and 12 months postinsertion. It was found that event rates did not differ significantly between the progesterone (1569 women-months) and the copper (1558 woman-months) devices. Greater pain on insertion (23.3% versus 15.4%), less metrorrhagia (7.5% versus 13.4%), and higher continuation rates after 1 year of use (87.2% versus 84.6%) were associated with the progesterone device. A flow decrease of 27.2% and increase of more than 22.3% was associated with the Copper-7. Duration of menstruation was not significantly different between the 2 groups, but the progesterone IUD users had more days of "spotting." In both groups, duration of menstruation increased by the end of the study year for a large number of women. This was significant only in Copper-7 users.
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  13. 13

    Patterns and perception of vaginal bleeding: a survey of knowledgeable resources in Egypt.


    September 1975. 41 p.

    Information gathered from knowledgeable sources (e.g., obstetricians, family doctors, pharmacists, nurses, family planning workers, and informal social network representatives) indicated the important position that menstrual bleeding, and the social implication related to it, holds in the life of Egyptian women. Menstrual bleeding is a sign of well-being, youth, fertility, and femininity. The majority of knowledgeable sources agreed that a normal cycle length among Eyptian women ranged from 21-32 days, whereas the normal bleeding interval ranged from 3-5 days. Abnormality, however, is a function of personal experience, i.e., a cycle is abnormal when it deviates from the woman's normal pattern. Egyptian women perceive menstrual blood as bad blood that they must lose every month, the retention is thought to result in bodily poisoning. Egyptian women are aware of specific color, smell, and texture of vaginal bleeding, and any change in quality or quantity is alarming. Illiterate women predict and recall their bleeding episodes by using a lunar calender which indicates national or religious ceremonies. Menarch is reported to be an occasion of joy signifying womanhood, whereas menopause is resented and dreaded, associated with drying or shrinking of the uterus. Menstruation is induced by various folk means, because it is believed that retention of blood causes cramping and that blood flow will alleviate that pain. The cleansing ritual after each cycle has both physical and religious importance.
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  14. 14

    Periodic abstinence for family planning.

    Kleinman RL

    London, International Planned Parenthood Federation, 1983. 60 p. (IPPF Medical Publications)

    This publication provides comprehensive information and instructions for the various ways of using periodic abstinence for contraception, along with a restatement of the position of the International Planned Parenthood Federation that periodic abstinence cannot be considered an equal alternative to other more effective family planning methods but that it should be offered by family planning associations for couples desiring it for religious or other reasons. The manual describes the historical development of the abstinence methods and reviews the physiology of the menstrual cycle as background for the careful instructions for each variant. The methods covered include the basal body temperature method in which the "3 over 6" rule for identifying the temperature shift is endorsed but others, such as the cervical mucus method, cervical palpation, sympto-thermal method, and calendar method are described. Other chapters discuss the psychological and motivational aspects of use of periodic abstinence methods; identify research issues and present data on effectiveness especially of the cervical mucus and sympto-thermal methods; discuss side effects and advantages and disadvantages of the methods; and consider special problems of use in developing countries.
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  15. 15

    Biological approaches to ovulation detection.

    Bonnar J

    In: Jeffcoate SL, ed. Ovulation: methods for its prediction and detection. Chichester, England, John Wiley, 1983. 33-47. (Current Topics in Reproductive Endocrinology Volume 3)

    This chapter reviews certain recognizable biological effects that occur due to the major changes in the circulating blood levels of estrogen and progesterone and discusses the ongoing use of these biological signals for the self detection of ovulation and the fertile phase of the cycle. These biological changes include the basal body temperature, changes in the cervix and its mucus secretion, mittelschmerz, and the menstrual cycle molimina. The calculation or calendar method is the oldest technique for determining the fertile period and followed the work of Ogino (1930) and Knaus (1933). The fertile phase of the cycle was identified from the records of the previous 6-12 menstrual cycles. The potential fertile period was then calculated on the following basis: define the shortest and the longest menstrual cycle over the preceding 6 and preferable 12 cycles; the 1st day of the potentially fertile phase is the longest cycle minus 11 days. For a women whose menstrual cycles have varied between 26-31 days, the potential fertile period would be days 8-20 of the cycle. The greatest weakness of the calendar calculation is that it depends on a prediction, based on the menstrual history, of what is likely to occur and not on what is actually taking place. Very rapid electronic thermometers are now available which offer considerable advantages over the clinical thermometer. The daily taking and charting of the basal body temperature (BBT) is the simplest and most widely used method for detecting ovulation. To overcome the drawbacks of the calendar method and the BBT method for identifying the fertile period, John and Evelyn Billings of Melbourne in the early 1970s developed the ovulation method. Self recognition of cervical mucus symptoms provides the woman with a simple means of detecting the fertile phase of her cycle and the likely time of ovulation. Individual cycle variation in the preovulatory duration of the symptoms limits the position of the prediction, yet the "peak" day correlates better with the time of ovulation than the shift in BBT. In addition to effects on cervical mucus, estrogen also changes the morphology of the cervix. The preovulatory rise in estrogensoftens the tissues of the cervix and opens the cervical os. The softened cervix and gaping os with a cascade of clear mucus is a sign of optimal estrogen response and of imminent ovulation. A World Health Organization (WHO) multicenter study of the ovulation method provided a substantial amount of information of the normal menstrual cycle of a large number of women of proven fertility in the age group 18-39 years whose cycles were not influenced by the use of hormonal or other contraceptive methods.
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  16. 16
    Peer Reviewed

    A randomized, double-blind study of six combined oral contraceptives.

    World Health Organization [WHO]. Special Programme of Research, Development and Research Training in Human Reproduction. Task Force on Oral Contraceptives

    Contraception. 1982 Mar; 25(3):231-41.

    A randomized, controlled, clinical trial comparing 6 combined oral contraceptives (OCs) with 50 mcg or less of ethinyl estradiol was undertaken in 10 WHO Collaborating Centers for Clinical Research in Human Reproduction. A total of 2430 women entered the trial and were observed for 28,077 woman-cycles. All low-dose combined OCs demonstrated equivalent efficacy with 1-year pregnancy rates of 1-6%. However, discontinuation rates for medical reasons differed significantly between the treatment groups with the preparation containing 20 mcg ethinyl estradiol and that containing 400 mcg norethisterone acetate being associated with higher discontinuation rates due to bleeding disturbances. Even among the preparations which did not differ in discontinuation rates, the reasons for discontinuation did differ. Women receiving norethisterone preparations tended to discontinue because of bleeding disturbances while those receiving the levonorgestrel-containing preparations tended to discontinue because of complaints of nausea and vomiting. (author's)
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