Hormonal Contraceptive Pills Research Articles

Effect of a combined estrogen and progesterone oral contraceptive on circulating adipocytokines adiponectin, resistin and DLK-1 in normal and obese female rhesus monkeys

BackgroundHormonal contraception is the most common medication used by reproductive aged women but there is little understanding of the impact of hormonal contraception on obesity and metabolism. Adipokine levels (adiponectin, resistin) and markers of adipocyte development (DLK-1) are altered in obese animals and humans and are associated with increased cardiovascular risk. We sought to determine the effect of combined hormonal oral contraceptive pills (COCs) on circulating adiponectin, resistin and DLK-1 levels in obese and normal-weight rhesus macaque monkeys. MethodsSerum adiponectin, resistin and DLK-1 levels in reproductive-age female rhesus macaques of normal (n = 5, mean = 5.76 kg) and inherently obese (n = 5, mean = 8.11 kg) weight were determined before, during and 2 months after cessation of 8 months of continuous treatment with COCs. ResultsThe obese group alone showed a significant decrease (p<.01) in weight with COC use, which returned to baseline after COC cessation. Baseline adiponectin levels prior to COC treatment were lower in the obese group (p<.05). Adiponectin levels increased from baseline in both groups, but more so in the obese group (p<.05). Resistin levels were similar at baseline, with an increase in both groups following treatment. Circulating resistin remained elevated above baseline levels after COC cessation, particularly in the obese group (p<.05). While DLK-1 levels did not change significantly in either group, a trend for higher levels in obese animals was observed. ConclusionsCOC use may alter metabolic processes via direct (resistin) or indirect (adiponectin) means, while unchanging DLK1 levels suggest they do not affect adipocyte development. COCs may directly increase resistin levels, as observed in both groups. As adiponectin is inversely related to adipocyte mass, increased levels in the obese group are likely attributed to weight loss.

Long-term administration with levonorgestrel decreases allopregnanolone levels and alters GABAA receptor subunit expression and anxiety-like behavior

Fluctuations in the concentrations of the neuroactive steroid allopregnanolone are thought to influence γ-amino-butyric acid type A (GABAA) receptor gene expression and function. Long-term treatment with ethinyl estradiol (EE) plus levonorgestrel (LNG), two of the most widely used steroids in the hormonal contraceptive pill, decreases allopregnanolone levels in rat cerebral cortex and plasma, alters GABAA receptor expression and induces anxiety-like behavior. We evaluated which component of the hormonal contraceptive pill is responsible for the aforementioned changes. Female rats were injected subcutaneously (s.c.) with EE (0.030mg) or LNG (0.125mg) once a day for 4 weeks. Compared to the respective vehicle-treated control groups, EE decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 76, 72 and 33%, respectively and hippocampal levels by 52, 56 and 50%, respectively. Likewise, LNG decreased cerebral cortical levels of allopregnanolone, progesterone and pregnenolone by 75, 68 and 33%, respectively, and hippocampal levels by 55, 65 and 60%, respectively. Administration of LNG, but not EE, increased the abundance of the γ2 subunit peptide in cerebral cortex and hippocampus by 38 and 59%, respectively. Further, LNG, but not EE, decreased the time spent and the number of entries into the open arms of the elevated plus maze by 56 and 43%, respectively, an index of anxiety-like behavior. These results suggest that alterations in GABAA receptor subunit expression and anxiety-like behavior induced by long-term treatment with combined EE/LNG appear to be caused by LNG. Given that both EE and LNG decrease allopregnanolone levels in a similar manner, these results further suggest that changes in allopregnanolone levels are not associated with GABAA receptor expression.

The management of menstrual suppression and uterine bleeding: A survey of current practices in the pediatric blood and marrow transplant consortium

Current guidelines recommend the use of combined hormonal contraceptive pills for menstrual suppression in pediatric blood and marrow transplant (BMT) recipients but recent research reveals that provider practice varies. This study was designed to describe the current practice for managing menstrual issues, that is, menstrual suppression and uterine bleeding, in pediatric BMT patients and to better understand health care providers' practices in the use of gonadotropin-releasing hormone agonists (GnRHa). A cross sectional survey consisting of 53 questions was distributed via email to principal investigators in the Pediatric Blood and Marrow Transplant Consortium (PBMTC). Responses were collected using www.surveymonkey.com. Menstrual suppression and uterine bleeding in pediatric BMT patients are primarily managed by pediatric oncologists (97%). The most frequently reported hormonal method used for induction of therapeutic amenorrhea was GnRHa (41%). The top three reasons for choosing a method were greater likelihood of amenorrhea, concerns about side effects, and possible gonadal protection. Continuous combined hormonal contraceptive pills were the most commonly used method for the management of clinically significant uterine bleeding regardless of primary method used for menstrual suppression. Despite the 2002 PBMTC guidelines, wide variation in menstrual suppression management practices still exists. Our data show that use of GnRHa is more common than previously reported. Additional research is needed to develop evidence-based practice guidelines in pediatric BMT patients.

Effect of Progestin Compared With Combined Oral Contraceptive Pills on Lactation

To estimate the effect of progestin-only compared with combined hormonal contraceptive pills on rates of breastfeeding continuation in postpartum women. Secondary outcomes include infant growth parameters, contraceptive method continuation, and patient satisfaction with breastfeeding and contraceptive method. Postpartum breastfeeding women who desired oral contraceptives were randomly assigned to progestin-only and combined hormonal contraceptive pills. At 2 and 8 weeks postpartum, participants completed in-person questionnaires that assessed breastfeeding continuation and contraceptive use. Infant growth parameters including weight, length, and head circumference were assessed at 8 weeks postpartum. Telephone questionnaires assessing breastfeeding, contraceptive continuation, and satisfaction were completed at 3-7 weeks and 4 and 6 months. Breastfeeding continuation was compared between groups using Cox proportional hazards regression. Differences in baseline demographic characteristics and in variables between the two intervention groups were compared using χ tests, Fisher exact test, or two-sample t tests as appropriate. Breastfeeding continuation rates at 8 weeks (progestin-only 63.5%; combined hormonal 64.1%), contraceptive continuation, and infant growth parameters did not differ between users of progestin-only and combined hormonal contraceptive pills. Infant formula supplementation and maternal perception of inadequate milk supply were associated with decreased rates of breastfeeding in both groups. Choice of combined hormonal or progestin-only contraceptive pills administered 2 weeks postpartum did not adversely affect breastfeeding continuation. ClinicalTrials.gov, www.clinicaltrials.gov, NCT01465022.

Bacterial vaginosis: what is physiological in vaginal bacteriology? An update and opinion

Bacterial vaginosis (BV) was originally described as a sexually transmitted infection caused by a single microbe. The prevailing concept describes BV as a polymicrobial coitus-associated disease of uncertain origin. In this overview the natural history of BV as a monobacterial and polymicrobial entity is examined with respect to the physiological concept of BV in relation to sexual behavior before and after introduction of the hormonal contraceptive pill. Bacterial vaginosis, characterized by low vaginal acidity (elevated pH) and replacement of vaginal Lactobacillus by Gardnerella vaginalis flora, could be caused by unprotected intercourse when a low pH changes through the neutralizing power of male ejaculate, vaginal coital transudate and vaginal neurogenic transudate. A monobacterial form, G. vaginalis vaginitis, could be a physiological post-coital condition for protection of ejaculated spermatozoa, characterized by 'pure'Gardnerella flora and elevated pH as an immediate result of an incidental unprotected coital act through neutralization of vaginal acid and replacement of Lactobacillus by Gardnerella flora. A polymicrobial form of BV could be autoinfection of the post-coital physiological G. vaginalis flora, characterized by a mixture of G. vaginalis, Mycoplasma hominis and anaerobic bacteria at lower vaginal acidity, possibly resulting from suppression of normal vaginal acidity through repeated sexual acts, with a resultant higher pH and transfer of enteric bacteria from the perianal region. Monobacterial and polymicrobial auto-infectious forms of BV may be clinically distinct and share a common origin. The understanding of BV as a basic physiological entity could influence the prophylaxis and treatment of the largely therapy-resistant polymicrobial BV.

Safety of a Pulmonary Embolism Ambulatory Treatment Program

Objective: Evidence has emerged that out-patient management of pulmonary embolism may be an appropriate option in selected patients. This report is based on a safety data on a Pulmonary Embolism Ambulatory Treatment program.&#x0D; Methods: An observational study in acute assessment unit from 2000-2006, of all consecutive patients with confirmed pulmonary embolism (high probability ventilation-perfusion scan or computerized tomography pulmonary angiography), have been evaluated. Exclusion criteria were oxygen saturation less than 92%; systolic blood pressure less than 100 mm Hg; significant cardiopulmonary or renal disease, and a bleeding risk. Patient treated initially with low molecular weight heparin followed by oral anticoagulants when diagnosis was confirmed and were assessed at 3 and 6 months.&#x0D; Results: Sixty-one patients (33 females), median age 55 (range; 16-89 years) were eligible. Patients needed a maximum of 13 appointments. Risk factors included surgery (8.2%), cancer (8.2%), long travel (14.8%), previous thromboembolism (14.8%), hormonal replacement therapy (3.3%) and contraceptive pill (8.2%). No risk factor was identified at 37.7%. The mortality was zero at 6 months. No complications were recorded. Four patients required hospital admission, all within the first week; all were discharged within 24 hours. The median length of stay for patients with uncomplicated pulmonary embolism was 7 days; implementation of the pulmonary embolism ambulatory treatment program saved 427 bed days.&#x0D; Conclusion: The pulmonary embolism ambulatory treatment program was cost-effective and was not associated with serious complications. Further evaluation of these programs could help establish the safety and cost-effectiveness of this approach.

Safety of a Pulmonary Embolism Ambulatory Treatment Program

Objective: Evidence has emerged that out-patient management of pulmonary embolism may be an appropriate option in selected patients. This report is based on a safety data on a Pulmonary Embolism Ambulatory Treatment program.&#x0D; Methods: An observational study in acute assessment unit from 2000-2006, of all consecutive patients with confirmed pulmonary embolism (high probability ventilation-perfusion scan or computerized tomography pulmonary angiography), have been evaluated. Exclusion criteria were oxygen saturation less than 92%; systolic blood pressure less than 100 mm Hg; significant cardiopulmonary or renal disease, and a bleeding risk. Patient treated initially with low molecular weight heparin followed by oral anticoagulants when diagnosis was confirmed and were assessed at 3 and 6 months.&#x0D; Results: Sixty-one patients (33 females), median age 55 (range; 16-89 years) were eligible. Patients needed a maximum of 13 appointments. Risk factors included surgery (8.2%), cancer (8.2%), long travel (14.8%), previous thromboembolism (14.8%), hormonal replacement therapy (3.3%) and contraceptive pill (8.2%). No risk factor was identified at 37.7%. The mortality was zero at 6 months. No complications were recorded. Four patients required hospital admission, all within the first week; all were discharged within 24 hours. The median length of stay for patients with uncomplicated pulmonary embolism was 7 days; implementation of the pulmonary embolism ambulatory treatment program saved 427 bed days.&#x0D; Conclusion: The pulmonary embolism ambulatory treatment program was cost-effective and was not associated with serious complications. Further evaluation of these programs could help establish the safety and cost-effectiveness of this approach.

Adolescents’ Experiences Using the Contraceptive Patch versus Pills

Study ObjectiveTo compare use of the weekly transdermal contraceptive patch (patch) with daily combined hormonal contraceptive pills (pills) in adolescents. DesignProspective longitudinal study of adolescents’ self-selected (non-randomized) use of the patch or pills. SettingUrban, university hospital-affiliated, adolescent outpatient clinic. Participants13–22-year-old female adolescents seeking hormonal contraception, 40 who chose the patch and 40 who chose pills. InterventionsData were collected via self-report on paper questionnaires at three-cycle intervals for a total of up to nine cycles. Main Outcome MeasuresMethod continuation, perfect use, method satisfaction, quality of life, and side effects, including menstrual changes and perceived mood changes. ResultsAfter nine cycles, 38% of patch users and 60% of pill users were still using the method they had chosen at enrollment. There were no significant differences between the groups in self-reported perfect use. No differences were found in quality of life or side effects. Both patch and pill users noted menses became lighter and more predictable and reported decreased depression prior to their menses; only the pill group reported improvement in premenstrual anger. Method satisfaction was similar in both groups except patch users were more likely to report that their contraceptive method improved normal daily activities. ConclusionsDespite apparent advantages of the patch over the pill, adolescents using both methods continue to face challenges achieving perfect and sustained contraceptive use.

Ectopic pregnancy following levonorgestrel emergency contraception: a case report

Hormonal contraceptive pills containing 750 microgram levonorgestrel are the most commonly used postcoital contraceptive method because of their high efficacy and fewer side effects. Emergency contraceptive pills containing levonorgestrel present their effects by several mechanisms, including delayed tubal transport of the ovum. A delay of tubal transportation of an ovum is also one of the possible etiologic factors of tubal ectopic pregnancies. There are limited data on the risk of ectopic pregnancy following levonorgestrel treatment as an emergency contraception. Here, a case of tubal pregnancy associated with the use of levonorgestrel containing emergency contraceptive pills has been presented along with discussion of the relevant literature.

Missed Hormonal Contraceptives: New Recommendations

ObjectiveTo provide evidence-based guidance for women and their health care providers on the management of missed or delayed hormonal contraceptive doses in order to prevent unintended pregnancy. EvidenceMedline, PubMed, and the Cochrane Database were searched for articles published in English, from 1974 to 2007, about hormonal contraceptive methods that are available in Canada and that may be missed or delayed. Relevant publications and position papers from appropriate reproductive health and family planning organizations were also reviewed. The quality of evidence is rated using the criteria developed by the Canadian Task Force on Preventive Health Care. Benefits, Harms, and CostsThis committee opinion will help health care providers offer clear information to women who have not been adherent in using hormonal contraception with the purpose of preventing unintended pregnancy. Sponsors: The Society of Obstetricians and Gynaecologists of Canada. Summary Statements1.Instructions for what women should do when they miss hormonal contraception have been complex and women do not understand them correctly. (I)2.The highest risk of ovulation occurs when the hormone-free interval is prolonged for more than seven days, either by delaying the start of combined hormonal contraceptives or by missing active hormone doses during the first or third weeks of combined oral contraceptives. (II) Ovulation rarely occurs after seven consecutive days of combined oral contraceptive use. (II) Recommendations1.Health care providers should give clear, simple instructions, both written and oral, on missed hormonal contraceptive pills as part of contraceptive counselling. (III-A)2.Health care providers should provide women with telephone/electronic resources for reference in the event of missed or delayed hormonal contraceptives. (III-A)3.In order to avoid an increased risk of unintended pregnancy, the hormone-free interval should not exceed seven days in combined hormonal contraceptive users. (II-A)4.Back-up contraception should be used after one missed dose in the first week of hormones until seven consecutive days of correct hormone use are established. In the case of missed combined hormonal contraceptives in the second or third week of hormones, the hormone-free interval should be eliminated for that cycle. (III-A)5.Emergency contraception and back-up contraception may be required in some instances of missed hormonal contraceptives, in particular when the hormone-free interval has been extended for more than seven days. (III-A)6.Back-up contraception should be used when three or more consecutive doses/days of combined hormonal contraceptives are missed in the second and third week until seven consecutive days of correct hormone use are established. For practical reasons, the scheduled hormone-free interval should be eliminated in these cases. (II-A)7.Emergency contraception is rarely indicated for missed combined hormonal contraceptives in the second or third week of the cycle unless there are repeated omissions or failure to institute back-up contraception after the missed doses. In cases of repeated omissions of combined hormonal contraceptives, emergency contraception may be required, and back-up contraception should be used. Health care professionals should counsel women in these situations on alternative methods of contraception that do not demand such stringent compliance. (III-A)

P.225 Spontaneous viral clearance in patients with acute hepatitis C in Egypt

This article presents the results of focus group discussion sessions conducted with a sample of continuers and discontinuers of the once-a-month injectable contraceptives Cyclofem® and Mesigyna®, as well as with some of the physicians who participated in the clinical trial. The sessions helped explain certain aspects related to the clients as well as the service delivery setting that affected the acceptability of these contraceptive preparations. Providing counseling and presence of a dedicated clinic staff were very essential to the success of the clinical trial. Social support in the form of both husband knowledge, approval, and support as well as the presence of other close relative or friend users helped in increasing the woman’s tolerance of side effects and sometimes helped overcome adverse rumors. Reaction of the women to vaginal bleeding in an Islamic society is discussed and the need for health education in this aspect is strongly recommended. The two preparations are best suited for women who were satisfied with the use of combined hormonal contraceptive pills but had a problem with compliance, and users of other hormonal methods who are free from menstrual irregularities. On the whole, the two preparations had high acceptability among Egyptian women, provided that procedures for the selection of the appropriate candidate are adhered to, and that pre- and postservice counseling and social support are present.

Blutungen - muss dass sein?

More and more women request less menstruation and would refuse temporarily or completely gladly onto the menstruation and the accompanying symptoms. Through the continuous conquest of the oral hormonal contraceptive pills in the long-cycle treatment can the loss of blood reduced, breakthrough bleeding and spotting can be decreased or prevented and the complaints occurring with menstruation as well as menstruation conditional provocations for cycle dependent illnesses can be reduced or prevented. The long cycle is a genuine alternative for these women to the improvement in living quality and hygiene even if for this purpose extensive great studies are not yet available.

Emergency contraception: Current trends, possibilities and limitations

Emergency contraception has been used for over three decades. Indications for emergency contraception are intercourse without contraceptive protection or inadequate application of other contraceptive means. Also, this method is the only way out in situations when sexual intercourse has proceeded not only without protection, but also without voluntary agreement of both partners. Despite of their proven efficiency, it is thought that application of contraception means, even in countries with highly developed systems of health care, is far below optimal. Contemporary studies have pointed out some new posibilities and novel, modified methods of emergency contraception have been proposed. Basic methods of emergency contraception include use of hormonal preparations and postcoital insertion of intrauterine copper devices. Hormonal preparations that are used in emergency contraception are: combined hormonal contraceptive pills, levonorrgestrel and antiprogestin mifepristone. In 1998, the method with levonogestrel only, was indicated by World Health Organization as a "golden standard" in hormonal emergency contraception. The article gives a survey of new trends, possibilities and limitations of modern emergency contraception, with the aim of popularization of this form of contraception in our country.

Risk factors for thromboembolism in teens: when should I test?

The discoveries of the factor V Leiden mutation and the prothrombin gene variant 20210 in the last decade have markedly contributed to the understanding of the molecular pathophysiology of inherited risk factors for thrombophilia. Population studies in the adult literature have shown that although the overall prevalence of these defects is low, affected individuals are at increased risk of thrombosis particularly if acquired risk factors for thrombosis are also present. The use of combined hormonal oral contraceptive pills is a well-known acquired risk factor, and recent studies have shown significant increased risk of thrombosis for women who carry the factor V Leiden mutation and use oral contraceptive pills. Despite this significant increased risk, mass screening of asymptomatic women for factor V Leiden prior to prescribing oral contraceptive pills is not a cost-effective use of health care dollars and could result in unnecessarily preventing many women from the contraceptive and noncontraceptive benefits of this medication. Instead, clinicians can use thoughtful screening questions to identify potentially high-risk patients for thrombophilia and consider testing for inherited risk factors on a case-specific basis.

Emergency Contraception Over-The-Counter

In Brief Requiring a physician's prescription for hormonal emergency contraceptive pills makes no sense. Unintended pregnancies remain endemic in the United States, and wider use of emergency contraceptive pills could substantially help. However, the prescription requirement poses an unnecessary barrier to prompt, effective use of this preventive therapy. According to the Durham-Humphrey Amendment of 1951, the default option for all new drugs is, in principle, over-the-counter, unless a drug is addictive or dangerous when self-administered. Clearly, hormonal emergency contraception is neither of these. Emergency contraceptive pills meet all the customary criteria for over-the-counter use: low toxicity, no potential for overdose or addiction, no teratogenicity, no need for medical screening, self-identification of the need, uniform dosage, and no important drug interactions. The Food and Drug Administration is authorized, and, by its own regulations, should be required to switch hormonal emergency contraception to over-the-counter status without delay. The current prescription requirement is not only gratuitous but also harmful to women's health because it impedes access to this important therapy. Both the public health need and Food and Drug Administration regulations mandate a switch of hormonal emergency contraception from prescription-only to over-the-counter status.

Emergency contraception over-the-counter: the medical and legal imperatives

Requiring a physician’s prescription for hormonal emergency contraceptive pills makes no sense. Unintended pregnancies remain endemic in the United States, and wider use of emergency contraceptive pills could substantially help. However, the prescription requirement poses an unnecessary barrier to prompt, effective use of this preventive therapy. According to the Durham-Humphrey Amendment of 1951, the default option for all new drugs is, in principle, over-the-counter, unless a drug is addictive or dangerous when self-administered. Clearly, hormonal emergency contraception is neither of these. Emergency contraceptive pills meet all the customary criteria for over-the-counter use: low toxicity, no potential for overdose or addiction, no teratogenicity, no need for medical screening, self-identification of the need, uniform dosage, and no important drug interactions. The Food and Drug Administration is authorized, and, by its own regulations, should be required to switch hormonal emergency contraception to over-the-counter status without delay. The current prescription requirement is not only gratuitous but also harmful to women’s health because it impedes access to this important therapy.

Scottish hormonal contraceptive pill knowledge audit

Scottish hormonal contraceptive pill knowledge audit

Acceptability of once-a-month injectable contraceptives cyclofem® and mesigyna®: focus group discussion

This article presents the results of focus group discussion sessions conducted with a sample of continuers and discontinuers of the once-a-month injectable contraceptives Cyclofem® and Mesigyna®, as well as with some of the physicians who participated in the clinical trial. The sessions helped explain certain aspects related to the clients as well as the service delivery setting that affected the acceptability of these contraceptive preparations. Providing counseling and presence of a dedicated clinic staff were very essential to the success of the clinical trial. Social support in the form of both husband knowledge, approval, and support as well as the presence of other close relative or friend users helped in increasing the woman’s tolerance of side effects and sometimes helped overcome adverse rumors. Reaction of the women to vaginal bleeding in an Islamic society is discussed and the need for health education in this aspect is strongly recommended. The two preparations are best suited for women who were satisfied with the use of combined hormonal contraceptive pills but had a problem with compliance, and users of other hormonal methods who are free from menstrual irregularities. On the whole, the two preparations had high acceptability among Egyptian women, provided that procedures for the selection of the appropriate candidate are adhered to, and that pre- and postservice counseling and social support are present.

Evidence for the Acceptability of an Injectable Hormonal Method for Men

Research has been conducted for more than 20 years in both developed and developing countries in the attempt to develop a safe, effective, and reversible hormonal method of contraception for men. A variety of hormonal compounds and contraceptive delivery systems, including injections, pills, implants, and patches, are therefore currently being investigated. Limited funding and a lack of commercial interest in regulating male fertility have, however, slowed progress. It seems that pharmaceutical companies doubt the existence of a market for hormonal contraceptives for men and fear the potential for litigation. Clinical trials, supported by the World Health Organization, of a hormonal method have nonetheless yielded encouraging results. One multicenter study injected men weekly with testosterone enanthate to induce azoospermia. A second study investigated whether the state of complete azoospermia induced by the injections was necessary for contraceptive efficacy. Testosterone enanthate demonstrated its potential application as a hormonal method of contraception for men, but the frequent injections required over the course of 3-4 months to achieve oligozoospermia are impractical. In addition, above normal levels of testosterone result immediately after injection. Testosterone enanthate in future trials will be combined with another hormone to shorten the time needed to achieve a contraceptive effect, or a new formulation which requires less frequent injections and does not produce a physiological peak. A newly formulated product could be ready for introductory trials by 2000. The author presents information from focus group discussions and questionnaires completed by men who volunteered for the trials. Their feedback adds to the limited body of evidence indicating the potential acceptance of a hormonal method of contraception for men.

Hormonal contraception

The combination hormonal contraceptive pill consisting of a fixed ratio of a progestational compound to an estrogenic compound administered from the 5th to 25th day of the cycle approaches 100% in efficacy. Cycle control is excellent and is related to the mechanism of action. The progestogen plus estrogen of the combination pill inhibit the hypothalamic-anterior pituitary-ovarian axis, thus insuring almost complete inhibition of ovulation and endogenous steroid hormone biosynthesis. The lack of endogeneous hormone is not critical since the pill replaces the lost hormones particularly as to uterine endometrial stimulation so that the tissue is prepared for a bleed on treatment withdrawal. The carefully timed hormonal replacement ensures excellent cyclicity. Although suppression of ovulation may be continued for years, cessation of treatment is followed by a return to normal hormonal function and fertility. Variants of the combination treatment include a once-a-month pill and a once-a-month injectable preparation. Both formulations are based on combinations of a progestogen plus estrogen. A high degree of efficacy approaching that seen for the combination pill has been achieved with a sequential regimen. In this procedure an estrogen alone is administered for 5 to 15 days while a mixture of estrogen plus a progestational agent is administered for the balance of the 20 days of treatment. Withdrawal of treatment brings on a bleed in 2 to 5 days. The mechanism of of antifertility is similar to that of the combination pill. Contraceptive efficiency of a high order may be attained with a small continuous dose of a progestational agent. The pregnancy rate and cyclicity are acceptable but not as good as that of the combination or sequential regimens. The pure progestogen treatment has been adapted to a pseudo post-coital therapy where one sexual contact requires one pill usually within 1 to 3 hours of the event. Thus far a reasonable efficacy has been established but as much as 33% of the cycles may be less than 20 days in length. A Single injection of a progestogen can produce effective antifertility for 90 days. This treatment is efficacious but the early treatment periods may involve considerable irregular bleeding and after repeated use ammenorrhea may be a problem. A true post-coital treatment has not been established. However, for emergency use 4 to 6 days of treatment with high doses of estrogen is highly effective in preventing pregnancy. The mechanism may involve speeding of ova transport thus preventing implantation.