Studies on low-dose oral contraceptives: cervical mucus and plasma hormone changes in relation to circulating D-norgestrel and 17alpha ethynyl-estradiol concentrations

Methods and considerations for the use of hormonal contraceptives in rat models of neurobehavior

Hormonal contraceptives (HCs), prescribed to millions of women around the world, alter the ovarian hormonal cycle resulting in neurobehavioral changes in HC users. Human epidemiological and experimental data has characterized some of these effects with oftentimes conflicting or irreproducible results, reflecting a dearth of research considering different compositions, routes of administration, or time-courses of HC use. Non-human animal research can model these effects and help elucidate the underlying mechanisms by which different HCs modulate neurobehavioral outcomes. Still, animal models using HCs are not well-established. This may be because the pharmacological profile of HCs - including the metabolism, receptor binding affinity, and neuromodulatory effects - is dynamic and not always clearly translatable between animals and humans. The current review addresses these issues and provides basic methods and considerations for the use of HCs in animal models of neurobehavior to help advance the field of behavioral neuroendocrinology and inform decisions regarding to women's health.

Pharmacodynamics of combined estrogen-progestin oral contraceptives: 4. Effects on uterine and cervical epithelia

Introduction: Steroid hormones are responsible for specific changes in the endometrium during the menstrual cycle, when they are sequentially secreted and, because of this, in the early days sequential combined oral contraceptive regimens were utilized. The same basic concept has been utilized with multi-phasic regimens, in order to produce endometrial pictures mimicking the normal cycle.Areas covered: The Endometrial effects of progestins and estrogens; combined monophasic high- (50 μg), medium- (30 μg), low- (20 μg), ultralow- (15 μg) estrogen content; sequential regimens; multiphasic combinations; treatment schedules.Cervical effects of combined high-dose and sequential combinations, including evidence for an increase in malignant lesions.Expert opinion: Overall, combined oral contraceptives (COCs) inhibit normal proliferative changes and the endometrium becomes thin, narrow, with widely spaced glands and pre-decidual changes in the stroma. During the first few cycles the progestin induces a coexistence of proliferative and secretory features; with time, the picture changes because the progestin induces a down-regulation of estrogen receptors, resulting in tortuous glands similar to those in the secretory phase, but characterized by a quiescent, atrophic glandular epithelium.In the cervical epithelium, under the influence of high-dose COCs, endocervical glands became hypersecretory and in some instances, distinctive type of atypical polypoid endocervical hyperplasia is found.

Comparison of cervical mucus of 24/4 vs. 21/7 combined oral contraceptives

BACKGROUND

Few studies have examined the action of combined oral contraceptives (COCs) on cervical mucus. We hypothesized that midcycle cervical mucus of women taking COCs is of poor quality when compared to their own midcycle mucus prior to initiating COCs. We sought to compare the effect upon quality and sperm penetration of the cervical mucus on the last hormone-free day with a 24/4 regimen to a 21/7 regimen.

METHODS

This is an open-label, investigator-blinded, randomized, controlled, crossover equivalency study. All subjects received, in random order, 2 months of a 21/7 regimen and 2 months of a 24/4 regimen, each containing 20 mcg ethinyl estradiol and 1 mg norethindrone acetate. Analysis of cervical mucus quality (CMQ) and sperm penetration took place midcycle and on the last day of the hormone-free interval during the second month of each COC treatment.

RESULTS

From April 2010 to November 2011, 18 subjects completed all study visits. Mean midcycle CMQ was poor (mean CMQ=1) and did not differ between 24/4 and 21/7 regimens (p=.92). On the last day of the pill-free interval, the quality and sperm penetration were poor with both regimens.

CONCLUSION

This study indicates that thickening of cervical mucus is a major mechanism of contraceptive action of COCs and that both 21/7 and 24/4 regimens result in poor quality and impenetrable mucus on the last day of the pill-free interval.

Side effects of steroid contraception

Side effects of steroid contraception during lactation are discussed and followed by a review of the relevant literature. It appears that oestrogen has an inhibiting effect on lactation performance, but progestogen alone does not. Most of the undesirable systemic side effects of oral contraceptives on the mother are connected with the relative excess or deficiency of the oestrogen and/or the progestogen component. It is likely that a low oestrogen content preparation causes no dangerous side effects. There are few data about the appearance of contraceptive steroids in breast milk. Probably only a small proportion of the steroids are excreted into the milk. Any adverse effects, on the infant, such as slow weight gain, neonatal breast hypertrophy and breast milk jaundice, are dependent on the two preceding factors. It is doubtful whether the small amount of contraceptive steroids contained in modern pills exert any influence on the fetus. Although further examinations are necessary, the low dosage of progestogen and oestrogen combined contraceptives given at fully established lactation under close control seems to be advantageous to both mothers and their infants.

Hormonal contraception

Hormonal contraceptives have been a part of clinical practice for more than 40 years, and family planning programs, based largely on contraceptive provision, are regarded as one of the most successful public health interventions of the 20th century. Thus, discussion of family planning issues and contraceptive considerations has become an integral component of women's health care and one of the benchmarks of the traditional annual well-women visit. In terms of cost-effectiveness, prevention of unplanned pregnancies through contraceptive use has repeatedly been shown to be a highly cost-effective use of health care dollars. Options for effective hormonal contraception have expanded tremendously and include a variety of delivery options, including the pills both in traditional 21/7 format, and more recently in a 24/4 format, as well as a vaginal ring, a skin patch, implants, and the hormonally medicated intrauterine device. Importantly, the overall risks associated with hormonal contraceptives have been reduced as compared with older formulations, even for women with medical conditions. Many modern hormonal contraceptives also offer valuable noncontraceptive benefits. To help clinical decision making, a number of evidence-based guides have been published, and the American College of Obstetricians and Gynecologists has recently updated their practice bulletin on contraception use in women with medical conditions. In general, clinical protocols for provision of hormonal contraceptives have been streamlined, and unnecessary practices, tests, and procedures are identified and discouraged. In this review, we will summarize both technical and programmatic aspects of hormonal contraceptive use, and methods are discussed in order of efficacy from highest to lowest.

Length of the menstrual cycle after discontinuation of oral contraceptives

OBJECTIVE

To investigate whether the first cycle after stopping oral contraceptive (OC) intake had a normal duration.

METHODS

A retrospective study was performed in 680 women, 300 non-OC users and 380 women discontinuing OC intake. The length of one or two menstrual cycles was recorded.

RESULTS

In the non-user group, the median duration of both the first and second cycle was 29 days (range 18-97 and 20-56 days, respectively). In the OC user group the median duration from withdrawal bleeding until next menstruation was 30 (15-82) days. The second cycle lasted 29 (17-122) days. The duration of the first post-treatment cycle was not significantly different from the next cycle or the cycle length in non-users. When the subjects were divided into different age categories, a significantly longer first post-treatment cycle was observed in the group aged 18-24 years, but a shorter first post-treatment cycle in the group aged 25-29 years. No differences were seen in the higher age groups. The ethinyl estradiol dose of the OC preparation did not influence the results.

CONCLUSIONS

The first cycle after OC discontinuation had a normal duration.

The mechanism of action of hormonal contraceptives and intrauterine contraceptive devices

Modern hormonal contraceptives and intrauterine contraceptive devices have multiple biologic effects. Some of them may be the primary mechanism of contraceptive action, whereas others are secondary. For combined oral contraceptives and progestin-only methods, the main mechanisms are ovulation inhibition and changes in the cervical mucus that inhibit sperm penetration. The hormonal methods, particularly the low-dose progestin-only products and emergency contraceptive pills, have effects on the endometrium that, theoretically, could affect implantation. However, no scientific evidence indicates that prevention of implantation actually results from the use of these methods. Once pregnancy begins, none of these methods has an abortifacient action. The precise mechanism of intrauterine contraceptive devices is unclear. Current evidence indicates they exert their primary effect before fertilization, reducing the opportunity of sperm to fertilize an ovum.

Shorter pill-free interval in combined oral contraceptives decreases follicular development

The objective of the study was to determine the suppressive effect on ovarian activity of 20 micrograms ethinylestradiol plus 75 micrograms gestodene administered for 21 or 23 days. The study was designed as a double-blind, randomized, multicenter trial in 60 women. A pre-treatment cycle, three treatment cycles and a post-treatment period were monitored by ovarian ultrasound and by LH, FSH, 17 beta-estradiol and progesterone measurements every other day. No ovulation and no luteinized, unruptured follicle were observed. Suppression of ovarian activity was more pronounced by the 23-day regimen. 17 beta-Estradiol serum levels during the last six days of a cycle and during the first six days of the next cycle were significantly less (p < 0.05) in the 23-day regimen. The superiority of the 23-day regimen in comparison to the 21-day regimen with regard to the suppression of ovarian activity was shown in this study. The observed differences in the 17 beta-estradiol levels and follicular development between a 21-day and 23-day preparation combine to suggest that shortening the pill-free interval in combined oral contraceptives may increase the contraceptive safety margin in women on low-dose formulations.

Group comparison of serum ethinyl estradiol, SHBG and CBG levels in 83 women using two low-dose combination oral contraceptives for three months

Serum ethinyl estradiol (EE2), sex hormone-binding globulin (SHBG) and corticosteroid-binding globulin (CBG) concentrations were studied in healthy young women randomly allocated to one of two low-dose combination oral contraceptives containing 30 micrograms EE2 and either 75 micrograms gestodene (F) or 150 micrograms desogestrel (M) per unit. There was either no (formerly non-pill users) or one (pill users) wash-out cycle before the study started with a pill-free pretreatment cycle in which the hormone status and basal SHBG and CBG levels were measured. Treatment was for three months. During treatment cycles 1 and 3, there were three test days each. Seven serum samples were obtained up to four hours and one sample 24 hours after intake of the first, tenth and the last (21st) pill. Additional samples were taken prior to morning ingestion of pills 5 and 15. For each individual and each test day, a representative serum pool has been constructed for SHBG and CBG analysis. EE2 concentrations were analyzed in all individual samples by means of a specific and sensitive RIA using anti-EE2-6 beta-CMO-BSA antiserum. Area under the curves (AUC) up to 4 and 24 hours, Cmax and tmax were evaluated and compared between the two treatment groups (n = 40 for F, n = 43 for M). SHBG and CBG concentrations were measured using commercially available immunoassay kits. Groups were large enough to detect a difference in group means of 75% of one standard deviation (alpha = 0.05, 1-beta = 0.9) of target variables, which is equivalent to 28 pg EE2/ml for Cmax, 69 pg.h.ml-1 for AUCEE2 0-4h, 257 pg.h.ml-1 for AUCEE2 0-24h, 39 nmol/l SHBG and 13.4 micrograms CBG/ml. Results clearly demonstrate that there were no differences between the two treatment groups in any of the target variables at any of the six test days distributed over a three-month period. Mean SHBG and CBG pretreatment levels of about 70 nmol/l and 37 micrograms/ml, respectively, increased to about 210 nmol/l and 88 micrograms/ml during the first treatment cycle and to about 230 nmol/l and 93 micrograms/ml during the third treatment cycle. Whereas the time of maximum EE2 serum levels did not differ significantly between test days, Cmax, AUCEE2 0-4h and AUCEE2 0-24h values increased by 30-35% or 40-50%, respectively, when test days 10 and 21 were compared to test day 1. Similar results were found for the third treatment cycle.(ABSTRACT TRUNCATED AT 400 WORDS)

Ovarian follicles during oral contraceptive cycles: their potential for ovulation

Ovarian follicles of a preovulatory size were encouraged to develop by extending the pill-free period of combine, triphasic oral contraceptive (OC) cycles. Despite recommencement of OC therapy, most follicles continued to grow and then respond to gonadotropin administration by both rupture and luteinization. It is concluded that follicles developing during OC cycles have the potential for ovulation, but this is of doubtful clinical significance for the vast majority of women.

Contraceptive steroid concentrations in women with early active schistosomiasis: lack of effect of antischistosomal drugs

Plasma concentrations of the oral contraceptive steroids (OCS) ethinyloestradiol (EE2) and levonorgestrel (LNG) have been determined in women with early active schistosomiasis and compared to those obtained in healthy volunteers. Steroid concentrations following a single dose of Ovral (500 micrograms LNG, 50 micrograms EE2) or during a multiple dose regimen were unaffected by the disease. There was no significant effect of the antischistosomal drugs praziquantel (40 mg X kg-1) or metrifonate (10 mg X kg-1 X 3 at 2-week intervals) on plasma steroid concentrations. In regular users of OCS, significantly higher concentrations of LNG were observed than in women who received only a single dose. We conclude that there is no pharmacokinetic reason for withholding OCS from patients with early active schistosomiasis who are also receiving either praziquantel or metrifonate.

Mode of action of dl-norgestrel and ethinylestradiol combination in postcoital contraception. III. Effect of preovulatory administration following the luteinizing hormone surge on ovarian steroidogenesis

A combination of 1.0 mg dl-norgestrel and 0.1 mg ethinylestradiol was administered orally at 18 hours after the detection of luteinizing hormone rise and again at 30 hours in five 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) measured in a control (placebo) cycle with those in two consecutive treatment cycles. Treatment did not alter the steroid levels in one subject. P was suppressed in one or both treatment cycles of four subjects. E2 was suppressed in both treatment cycles of one subject and produced widely fluctuating patterns in another. The hormonal patterns in the two consecutive treatment cycles of the same individual were similar in all but one instance, where only the P level in the second treatment cycle was diminished. These results showed that this treatment can elicit steroidogenic responses of varying degrees and duration. The contraceptive action may lie in the altered P and/or E2 level at certain points in the menstrual cycle.

Why do inadvertent pregnancies occur in oral contraceptive users? Effectiveness of oral contraceptive regimens and interfering factors

Inadvertent pregnancies in combined pill users are not uncommon, and are usually due to errors of tablet taking. However, many factors may contribute to 'pill failure'. In this review the endocrine pharmacology of pill use and the changes reported with missed pills have been considered in detail. The influences of other factors including drug interactions have been reviewed and a series of recommendations made for reducing the risk of pregnancy in each of these circumstances.

The effect of ethinyl estradiol 20 mcg and levonorgestrel 250 mcg on the pituitary-ovarian function during normal tablet-taking and when tablets are missed

A new combined pill containing 20 micrograms of ethinyl estradiol and 250 micrograms of levonorgestrel has been developed. The safety margin of this type of low-dose preparation needed to be assessed and this was done by evaluating daily levels of LH, FSH, estradiol, progesterone, 1-NG and EE2 as well as cervical mucus characteristics in six patients when one and then two consecutive pills were deliberately omitted mid-way through the cycle. Results demonstrated that there was no evidence of breakthrough ovulation, although there was some continued ovarian steroidogenesis, a feature consistent with previous studies using combined preparations. Existing instructions to patients regarding missed pills should continue in order to ensure maximal contraceptive safety.

Plasma levels of ethinylestradiol (EE) during cyclic treatment with combined oral contraceptives

The purpose of the present study was to extend the still limited data concerning ethinylestradiol (EE) plasma levels after repeated daily ingestion of a combination pill during the course of classical cyclic treatment. Plasma EE levels were followed in 13 volunteers throughout, in total, 19 treatment cycles with either a 50 ug EE (+ 125ug d-norgestrel) or a 30 ug (+ 150ug d-norgestrel) containing oral contraceptive. In addition, single plasma EE determinations were performed in 110 chronic oral contraceptive users. Whereas different patterns in plasma EE levels (sampling 24 hours following last pill ingestion) were observed among the different volunteers, the mean levels increased progressively during treatment and reflected closely the differences in dosage. The values obtained in the volunteers at the end of the treatment cycle showed important interindividual variations. The findings during a first treatment cycle or during the following ones were similar and for different treatment cycles in the same patient, the patterns in plasma EE levels were consistent. The results for single plasma determinations in chronic contraceptive users (sampling between 8th and 21st day of treatment cycle, 9 to 24 hours since last pill ingestion) showed more pronounced interindividual variations, the individual EE levels being not correlated to parameters such as body weight, body surface, months of oral contraception prior to the study, sex hormone binding capacity or day of the cycle. However, significant differences in mean plasma EE levels were noticed for patients treated with different commercial preparations with identical EE content, suggesting the existence of differences in bioavailability. The relevancy of plasma EE determinations is discussed and from the results of the present study, it is concluded that a strictly standardized time of sampling is an absolute condition for obtaining interpretable results.

A radioimmunoassay for ethinyl oestradiol in plasma incorporating an immunosorbent, pre-assay purification procedure

A radioimmunoassay for plasma ethinyl oestradiol, featuring an immunosorbent extraction procedure, is described. Ethinyl oestradiol (EE2) was extracted using a non-specific, anti-oestrogen serum, raised to an oestradiol-17-hemisuccinate conjugate. The antiserum, coupled to microcrystalline cellulose, selectively extracted EE2 but not norethisterone ( NE), thus conferring specificity on a radioimmunoassay which has previously exhibited unacceptably high cross-reactivity with the synthetic progestagen, norethisterone, often used concomitantly with ethinyl oestradiol. This radioimmunoassay was shown to fulfil accepted assay validation criteria. Levels in subjects not receiving EE2 were less than 25 pmol/l. Circulating concentrations of EE2 could therefore be accurately determined in patients receiving low-dose combined preparations (EE2 35 micrograms; NE 500 micrograms).

Some estrogenic effects of two oral contraceptives consisting of norgestrel and two different doses of ethynylestradiol

Some biological and biochemical effects (i.e. KPI, cervical mucus, SHBG and ceruloplasmin) as well as serum ethynylestradiol and serum norgestrel, following the use of two oral contraceptives containing the same amount of norgestrel (dl-norgestrel 0.5 mg) and either 30 microgram or 50 microgram of ethynylestradiol were compared. There was no difference in the clinical features in either group of patients. There was a statistically significant difference in the levels of unconjugated ethynylestradiol but not in the other biochemical parameters studied. It is concluded that the absence of any such difference might be attributable to the strong antiestrogenic effects of dl-norgestrel.

Investigations of pharmacokinetics of ethinyloestradiol to specific consideration of a possible first-pass effect in women

Ethinyloestradiol-3H was given intravenously and orally to four and three women, respectively, in a dose of 60 micrograms and 3 mg. To another three female volunteers, 100 micrograms of ethinyloestradiol was administered by both routes in succession. Drug concentration in plasma and total radioactivity in plasma, urine and faeces were measured for different periods of time. Intraindividual comparison of the area under the drug level vs. time curve after intravenous and oral administration of 100 micrograms showed that ethinyloestradiol is subject to an about 60% first-pass effect in women. The time course of ethinyloestradiol concentration in plasma can be described by a 3-compartment model after intravenous injection and by a 2-compartment model after oral administration, because an early disposition phase with a half-life of about 15 minutes only becomes visible after i.v. injection. On an average, the terminal half-life of unchanged ethinyloestradiol level and total radioactivity was calculated to be about 1 day. However, a high variability was found with this parameter as well as with the rate and degree of elimination in urine.

Ethinyl estradiol in peripheral plasma after oral administration of 30 microgram and 50 microgram to women

Plasma levels of ethinyl estradiol were measured by radioimmunoassay in five women after oral administration of 30 microgram and of 50 microgram of ethinyl estradiol. Peak levels of ethinyl estradiol were mostly observed within two hours after the tablet intake. The peak concentrations found were 50--90 pg and 95--135 pg for the two doses administered. Twenty-four hours after the administration of the tablets, the plasma concentration of ethinyl estradiol did not exceed the plasma blank values (25 pg/ml) in most women.

Comparison of plasma hormone changes using a "conventional" and a "paper" pill formulation of a low-dose oral contraceptive

Two formulations of a low-dose oral contraceptive (Microgynon: 150 microgram of levonorgestrel [NG] +30 micrograms of ethynylestradiol [EE2]) were studied. The first was the "conventional" pill; the second was a "paper" pill prepared by evaporation of aliquots of a solution of the component steroids onto squares of edible cellulose separated by perforations, similar to a sheet of postage stamps. The effects of the two formulations on plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17beta-estradiol (E2), and progesterone were compared. Samples of blood were obtained from five women during a treatment period on the "conventional" pill and from five on the "paper" pill. When possible, blood samples were also obtained from a "control" cycle of each of these female subjects. Plasma LH, FSH, E2, and progesterone levels were determined by specific radioimmunoassay methods during control and treatment periods and NG and EE2 levels during treatment periods. Eight-hour plasma profiles for NG and EE2 at the beginning and in the later stage of the treatment periods were obtained and these samples were also analyzed for LH, FSH, E2, and progesterone. Results showed that with one exceptcrogynon were equally effective in suppressing ovulation. As in a previous study, FSH levels appeared to be one of the most sensitive indices of suppression.

Evidence of higher ethynylestradiol blood levels in human hypertensive oral contraceptive users

These studies were designed to investigate the differences in blood plasma levels of ethynylestradiol (EE2) in women who developed hypertension while taking combined estrogen and progesterone oral contraceptives (OCs) and in normotensive OC users. Blood samples were collected in heparinized tubes 10 hours after OC ingestion, the plasma was separated, and EE2 was measured by radioimmunoassay. The results showed significantly higher plasma levels of EE2 in the hypertensive OC users as compared with the levels in normotensive OC users (P less than 0.01). In another study, blood samples from hypertensive and normotensive OC users were obtained for 3 consecutive days at fixed intervals following OC ingestion, and plasma levels of EE2 were measured. The results showed consistently higher EE2 blood levels during this 3-day period in the hypertensive subjects (P less than 0.01). It is postulated that the higher blood levels of EE2 in hypertensive OC users result from either decreased metabolism or excretion of synthetic estrogens.