Inhibition of ovulation by means of a combined preparation with reduced amounts of active substance

Urinary hormonal profile during the first cycle of low-dose oral contraceptive pills in women

Ovarian function was studied in ten normal fertile women before and during the first cycle on a low-dose micropill containing 30 mcg ethinyl estradiol and 150 mcg L-norgestrel. In a control cycle and the first treatment cycle, steroid metabolites estrone-3-glucuronide (E1-3G) and pregnanediol-3 alpha-glucuronide (Pd-3G) were measured in daily early morning urine (EMU) samples. Also, luteinizing hormone (LH) was estimated during the expected periovulatory period. During the first cycle of micropill intake, ovarian function was suppressed in all cases. This is evidenced by significantly lower E1-3G and Pd-3G and absent midcycle LH peak compared to control cycles. The pattern of steroid metabolites was almost flat with no peaks. It is concluded that there is no need to cover the first cycle of micropill intake with other contraceptive methods.

A comparative analysis of three different dose combinations of oral contraceptives

Three different low-dose formulations of oral contraceptives were compared to determine the most suitable preparation for Filipino women as reflected in the first year continuation rates, incidence of side effects and failure rates. A total of 1,800 subjects were enrolled in the study from 18 health centers in six provinces in two regions of the Philippines, covering a total of 18,282 women-months of use. Sociodemographic characteristics were comparable. The monophasic levonorgestrel group showed the best performance followed by the triphasic preparation. The norethindrone group consistently showed higher drop-out rates, which may be due to the relatively higher incidence of side effects. For all three preparations, bleeding irregularities were low. There were no major side effects and no pregnancy was reported in one year of use. Noted was a distinct regional and provincial difference in recruitment and follow-up performance, possibly due to clinic, client or program factors.

Ovarian function is effectively inhibited by a low-dose triphasic oral contraceptive containing ethinylestradiol and levonorgestrel

For various metabolic and clinical reasons, it has been strongly advocated to reduce the dose of both the estrogen and progestogen components of oral contraceptives (OCs). In this study, we compared after 6 months of treatment, the action on various hormonal parameters of a standard-dose combined OC containing ethinylestradiol (EE) 0.050 mg and levonorgestrel (LNg) 0.250 mg and a low-dose triphasic combination containing a 59% reduced amount of the same steroids. Hormonal measurements in the last 3 days of OC intake indicated that basal levels of FSH and LH were less inhibited by the low-dose preparation, while PRL levels were unchanged. However, gonadal function was effectively inhibited by both high and low dose OCs, as demonstrated by equally low levels of E2, E1, P and 17-P. Consequently, no residual gonadal function could be anticipated from the observed low steroid concentrations. These results corroborated other studies (reviewed in this paper) in which serial hormonal measurements also revealed a complete lack of follicular maturation during low-dose triphasic OC treatment. Moreover, inhibition of circulating levels of A, DHEA, DHEAS, free T and DHT was similarly obtained with both preparations. Collectively, these data indicate that ovarian function is as effectively inhibited by a low-dose triphasic preparation as by a higher, standard-dose OC containing the same steroids.

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.

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

A study was undertaken to determine the effects of a low-dose oral contraceptive comprising 150 mug of D-norgestrel and 30 mug of 17alpha-ethynyl estradiol (Microgynon) on the plasma levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), 17BETA-ESTRADIOL, AND PROGESTERONE AND ON THE PHYSICAl properties of cervical mucus. Samples of blood and cervical mucus were obtained from three women during a treated cycle and the immediately-following "withdrawal" cycle. Specific radioimmunoassay methods were used to determine LH, FSH, 17beta-estradiol, and progesterone levels in treated and withdrawal cycles, and D-norgestrel and 17alpha-ethynyl estradiol in samples obtained during treated cycles. The concentration of synthetic steroids was also measured in blood samples obtained before and 1 hour after ingestion of the contraceptive to determine the maximal daily variation. The results indicated that the contraceptive action of this combined low-dose oral contraceptive is mediated through suppression of ovulation and by rendering the cervical mucus impenetrable to sperm. Plasma FSH levels appeared to be one of the most sensitive indices of suppression. Determination of D-norgestrel and 17alpha-ethynyl estradiol showed that 3 to 4 days were required to reach maximal plasma levels and that daily fluctuations were considerable. Withdrawal of the pill resulted in an immediate return to ovulatory cycles in all three subjects studied.

A review of recent developments in human fertility control

Recent and significant developments in the field of fertility control are reviewed. Consideration is given to new aspects of existing methods, recent modifications to steroidal formulations and Intrauterine devices, increased utilization of older methods (abortion and sterilization) and evaluation of new fields (postcoital contraception, prostaglandins and immunological techniques). There is an increasing demand for better application of newly developed methods and a rational decision in the selection of appropriate methods.

Clinical experience with ethinyl estradiol and d-norgestrel as an oral contraceptive

One hundred eighty-one women received 30 mug of ethinyl estradiol plus 150 mug of d-norgestrel as an oral contraceptive for 21 days and then received no tablets for the next seven days for a total of 1,488 cycles. There were no pregnancies. Cycle control was good to excellent. Menstrual cycles lasted 25 to 32 days in 96.2% of treatment cycles. Menstruation lasted three to five days in 93.2% of the cycles, and it began three to five days after the last day of medication in 79.1%. The menstrual flow was moderate in 87%. Breakthrough bleeding occurred in 2.0% of treatment cycles, spotting in 0.1%, and amenorrhea in 0.8%. The incidence of adverse subjective symptoms was minimal and significant increases compared with the pretreatment cycle were noted only for nausea in the first two cycles and for nervousness in the second cycle of treatment. Overall incidence of nausea was 3.2% of treatment cycles.