Effects of long-term low-dose mifepristone on reproductive function in women.

Low-dose antiprogestin administration has been proposed as a new contraceptive modality to interference with endometrial receptivity without disturbing ovarian function. The effects of 1 mg/day mifepristone for 150 days on the menstrual cycle were assessed in 21 surgically sterilized women. The aim was to study each woman for one control cycle and during months 1, 3 and 5 of treatment. Ovulation, endometrial thickness, serum oestradiol and progesterone, urinary luteinizing hormone, endometrial morphology and cervical mucus were assessed. Luteal phase progesterone concentrations were observed in 36 of the 60 treated months assessed and less frequently as treatment progressed. The bleeding pattern was regular in most biphasic cycles, while prolonged interbleeding intervals or no bleeding were associated with monophasic cycles. Altered endometrial morphology was found in all cases irrespective of the occurrence of luteal activity. Increased endometrial thickness and dilated glands were observed in 25 and 34% respectively of the monophasic cycles. Mifepristone, 1 mg/day, interferes with endometrial development while allowing the occurrence of biphasic ovarian cycles and regular bleeding. However, it also prevents ovarian cyclicity in a high proportion of treated months, and this is associated with increased endometrial growth in some women, which may be of concern.

PIP: Low-dose antiprogestin administration has been proposed as a new contraceptive modality that interferes with endometrial receptivity without disturbing ovarian function. To explore this potential, the effects on the menstrual cycle of 1 mg/day of mifepristone for 150 days were assessed in 21 surgically sterilized women from Santiago, Chile. Control cycles were biphasic in all 21 women and ovulatory in 20 women. Luteal phase progesterone concentrations were observed in 36 of the 60 treatment months (1, 3, and 5) assessed. The proportion of ovulatory cycles was highest during month 1 and decreased progressively with treatment. 40% of treatment cycles were monophasic and bleeding cyclicity was altered in 57%. Prolonged inter-bleeding intervals or no bleeding occurred in monophasic cycles. Endometrial morphology was altered in all cases, regardless of the occurrence of luteal activity. Increased endometrial thickness and dilated glands were recorded in 25% and 34%, respectively, of the monophasic cycles. These findings suggest that 1 mg of mifepristone interferes with endometrial development while allowing biphasic ovarian cycles and regular bleeding. Whether these endometrial alterations are sufficient to prevent implantation remains to be established. The long-term effect of prevention of ovarian cyclicity and the associated increased endometrial growth recorded in some women require further investigation.

Effects of a sequential regimen of mifepristone-medroxyprogesterone acetate on ovarian function, endometrial development and hormonal parameters.

The efficacy of a low dose of mifepristone, 5 mg/day for the first 15 days of the menstrual cycle, followed by medroxy-progesterone acetate (MPA), 10 mg/day for the next 13 days, for inhibiting ovulation was assessed in ten volunteers who were treated for three successive cycles. Hormonal determinations in blood and urine samples, ovarian ultrasonography and an endometrial biopsy taken on day 21-24 of the third treatment cycle were used to monitor the cycles. Ovulation was confirmed in 11 of the 30 treated cycles and, in these 11, the LH peak and follicular rupture occurred during MPA treatment periods. Out of 19 anovulatory cycles, 16 had no increase in progesterone levels and another 3 developed a luteinized unruptured follicle. Progestin administration induced secretory changes in the endometrium, but irregular or delayed development was found. Regular withdrawal bleeding occurred in all subjects. These data indicate that the sequential regimen can suppress ovulation while maintaining regular bleeding but increased efficacy is needed for phase II clinical trials.

PIP: The efficacy of a low dose of mifepristone, 5 mg/day for the first 15 days of the menstrual cycle, followed by medroxyprogesterone acetate (MPA), 10 mg/day for the next 13 days, for inhibiting ovulation was assessed in 10 Chilean volunteers who were treated for 3 successive cycles. They were healthy, surgically sterilized women with a mean age of 36.6 years and mean weight of 58.6 kg. Hormonal determinations in blood and urine samples, ovarian ultrasonography and an endometrial biopsy taken on days 21-24 of the third treatment cycle were used to monitor the cycles. Treatment inhibited ovulation during the 3 treatment cycles in 5 women. The regimen was partially effective in 3 women and totally ineffective in another 2 women. Ovulation was confirmed in 11 of the 30 treated cycles, and, in these 11, the luteinizing (LH) peak and follicular rupture occurred during MPA treatment periods. Out of 19 anovulatory cycles, 16 had no increase in progesterone levels and another 3 developed a luteinized unruptured follicle. Among the anovulatory cycles, 3 cycles presented a biphasic hormonal profile. In these 3 cycles the luteal phase progesterone level were much lower than in baseline cycles and they were associated with unruptured follicles. The other 16 cycles had a monophasic hormonal profile with no increase in progesterone levels in spite of a delayed rise in LH level. Progestin administration induced secretory changes in the endometrium, but irregular or delayed development was found. Only 9 post-treatment cycles were followed and 5 of these were ovulatory, 1 of them without a detectable LH midcycle peak. Regular withdrawal bleeding occurred in all subjects. These data indicate that the sequential regimen can suppress ovulation while maintaining regular bleeding, but increased efficacy is needed for phase II clinical trials.

Effects of continuous treatment with low dose mifepristone throughout one menstrual cycle.

The effects of continuous low dose mifepristone (RU 486) 10, 5 or 1 mg/day on the menstrual cycle were assessed in groups of five volunteers, who were treated for 30 days from the beginning of the cycle. Hormonal determinations in blood and urine samples, ovarian ultrasonography and an endometrial biopsy taken on day 22-29 of treatment were used to monitor the cycle. Pre- and post-treatment cycles presented a normal profile. During treatment, concentrations of RU 486 in plasma ranged from 65 nmol/l with 1 mg/day to 1000 nmol/l with 10 mg/day. With 10 or 5 mg/day, all treated cycles were prolonged as a result of arrested or slower follicular growth during treatment. Gonadotrophins, sex steroids and their urinary metabolites remained at early follicular phase levels throughout treatment, whereas androstenedione, prolactin and cortisol were unaffected. Follicular maturation resumed after discontinuation of treatment and several days later a luteinizing hormone surge followed by a luteal phase was observed in all cases. Ovulation was suppressed during treatment only in one of the five cycles treated with 1 mg/day. Endometrial maturation was disturbed by all doses. These data demonstrate a differential threshold of the follicle and the endometrium to mifepristone. This finding has potential application in the contraceptive field.

Variable effects of RU 486 on endometrial maintenance in the luteal phase extended by exogenous hCG.

This study was designed to assess the features and conditions for endometrial bleeding induction with the synthetic antiprogestin and antiglucocorticoid RU 486 during hCG-induced prolongation of the luteal phase. Eighteen healthy, surgically sterilized women and another five women with an intrauterine contraceptive device (IUD) participated. All subjects received hCG which was injected daily in increasing doses (500 to 15,000 IU) from day 9 to day 15 of the luteal phase. Ten subjects received hCG alone, and groups of three to 16 subjects received hCG combined with RU 486 (25, 50, 100, 200 or 400 mg/day). RU 486 administration was commenced on day 12 following the LH surge and given either for 1, 4 or 7 consecutive days. In certain cycles, tamoxifen (20 mg/day) was given for 4 consecutive days with hCG, or with hCG and RU 486. All treatment cycles were separated by one or two resting cycles. Frequent blood samples were taken to monitor the endocrine response. Treatment with hCG alone or with the various combinations of RU 486 produced similar serum levels of oestradiol and progesterone which were equivalent to those observed during early pregnancy. With hCG alone, the onset of bleeding was on day 21-24 after the LH surge, coinciding with the drop in oestradiol and progesterone. With RU 486 doses of 50 mg/day or more, an early bleeding episode almost invariably occurred on day 14-17 after the LH surge in the presence of high circulating steroid levels. In contrast, 25 mg/day RU 486 for 4 days failed to induce this early onset of bleeding in three out of six cases.(ABSTRACT TRUNCATED AT 250 WORDS)

PIP: When administered during the luteal phase of the menstrual period, human chorionic gonadotropin (hCG) has been observed to induce a pseudopregnancy in which the functional lifespan of the corpus luteum is prolonged. On the assumption that women with hCG-induced prolongation of the luteal phase offer an ideal model for studying the in vivo action of RU-486 and other antiprogestins, 23 women (5 of whom were IUD users) were administered hCG alone. hCG, and RU-486, tamoxifen, or both RU-486 and tamoxifen. Increasing doses of hCG produced a progressive rise in estradiol and progesterone to levels compatible with early pregnancy; steroid levels declined after cessation of hCG treatment and bleeding occurred 21-24 days after the midcycle luteinizing hormone (LH) surge. This indicates that the luteal phase was prolonged by at least 8 days. RU-486 doses of 50 mg/day and above produced bleeding 14-17 days after the LH surge in the presence of high levels of circulating steroids, while a 25 mg dose of RU-486 failed to produce bleeding in 50% of cases and tamoxifen failed to induce early bleeding or to potentiate the effect of RU-486 at either dose. A 2nd bleeding episode occurred 22-24 days after the LH surge coincident with a drop in circulating steroids in 43% of cycles; a 2nd bleeding episode was significantly correlated with a lower total dose (200 and 400 mg) of RU-486. Endometrial biopsies in those with late bleeding showed a mixed proliferative and secretory pattern indicative of incomplete shedding. A total dose of 700 or 800 mg of RU-486 is recommended to produce complete shedding.

On the rate of tubal pregnancy contralateral to the corpus luteum.

Ectopic implantation of the embryo in the tube opposite to the ovary containing the corpus luteum constitutes evidence of peritoneal or uterine transmigration of the egg. The frequency of this phenomenon was reinvestigated utilizing histopathologic confirmation of the side of the corpus luteum. A tubal pregnancy contralateral to the ovulating ovary was found in 28% of 67 cases, indicating that either the oocyte, the zygote or the embryo had entered the tube in which implantation took place from a medial site such as the peritoneal or the uterine cavity rather than directly from the ovulating ovary. Assuming that once in the medial site there is equal chance of entering either tube, it follows that in 56% of tubal pregnancies the egg has entered the tube from a midline location. Attempts to recover the oocyte from the tubes in normal women were successful in fewer than 5% of cases contralateral to the corpus luteum. It is concluded that tubal pregnancy is associated with a significant increase in the occurrence of transmigration of the egg.

Ectopic pregnancies associated with low dose progestagen-releasing IUDs.

Dimethyl-polysiloxane capsules containing pure progestagens were attached to Tatum's T IUDs and tested in 594 fertile women for contraceptive performance. The control group was represented by 71 women who received identical devices containing barium sulphate instead of steroid and 100 women who received a Copper T-200. The progestagens and the doses tested were megestrol acetate (4.8, 19.2, 26 and 32 micrograms/day; levonorgestrel (2.1, 3.4 and 8.5 micrograms/day); norethindrone (18 micrograms/day); R2323 (28.6 and 45 micrograms/day); and norgestrienone (26 micrograms/day). Twelve pregnancies were diagnosed during 5201 woman-months of exposure accumulated within the first year of use among users of the steroid-bearing IUDs. Five of these were ectopic gestations. Ten pregnancies, all uterine, were detected during 1701 woman-months of exposure in the control group. Intrauterine delivery of progestagens by means of a carrier IUD is effective in decreasing the pregnancy rate but it might effect postovulatory events in a way which increases the rate of tubal implantation. Because of this property, progestagen-releasing IUDs should be limited to doses that assure maximal effectiveness to avoid increasing the risk of ectopic pregnancy.

Correlation between histologic dating of human corpus luteum and the luteinizing hormone peak--biopsy interval.

The purpose of this study was to assess the accuracy of retrospective dating of ovulation in women based on the histologic dating of the corpus luteum. Corpora lutea enucleated from the ovary of 39 women between one and six days following the LH peak in plasma were examined by routine histologic techniques and dated according to Corner's criteria. The correlation between the luteinizing hormone (LH) peak--biopsy interval and histologic dating was assessed. Linear regression analysis of the data gave a correlation coefficient of 0.76. However, the dating of different corpora lutea obtained at the same LH peak--biopsy interval can differ by as much as four days. In addition, it was found that the stages named by Corner as days 1 and 2 seem to develop within the first 24 hours following the LH peak, while stages corresponding to days 4 and 5 each take two days to develop. It is concluded that the use of corpus luteum morphologic features for retrospective timing of ovulation is subject to an error of variable magnitude due to unequal duration of each stage, as well as considerable individual variation.

Studies on the duration of egg transport by the human oviduct. II. Ovum location at various intervals following luteinizing hormone peak.

The location of ova in the genital tract between 24 and 144 hours following the LH peak was determined in 23 normal women. Nineteen eggs were found in the Fallopian tubes between 24 and 96 hours and five eggs were recovered from the endometrial cavity between 96 and 144 hours following the LH peak. According to the present data and considering that ovulation occurs in the human subject nearly 17 hours after the LH peak, it is concluded that the transport of unfertilized ova in women is characterized by a period of retention in the ampulla, which lasts approximately 72 hours, followed by rapid transit through the isthmus and appearance of the ovum in the endometrial cavity around 80 hours after ovulation.

PIP: This study determined the location of ovum in the genital tracts of women at various intervals after the luteinizing hormone (LH) peak, in order to answer the following questions concerning ovum transport: 1) how soon and for how long after the LH peak can eggs be recovered from the fallopian tube, and 2) what is the relative time spent by eggs in each portion of the fallopian tube. Also addressed was the question of how soon, and for how long after the LH peak, can eggs be recovered from the uterus? 23 normal women were studied and their ova were located in their tubes after surgical intervention, which occurred from 24-144 hours after LH peak, based on results of blood assays for this hormone. In all 19 eggs were found in tubes between 24 and 96 hours and 5 eggs were recovered from the endometrial cavity between 96 and 144 hours after LH peak. Since it has been determined that ovulation occurs about 17 hours after LH peak, these data show that transport of unfertilized ova in women is characterized by a period of retention in the ampulla which last about 72 hours; this retention period is followed by very rapid ovum transit through the isthmus; the ovum appears in the endometrial cavity about 80 hours after ovulation.

Effect of 15(S)-15-methyl prostaglandin F2alpha on human oviductal motility and ovum transport.

The effects of an intravenous infusion of 15(S)-15-methyl prostaglandin F2alpha (PGF2alpha) on oviductal motility and ovum transport were studied in women who were scheduled for elective tubal sterilization. Infusion rates of 0.38 microgram/kg/hour or higher caused an increase in oviductal motility in all patients. Lower infusion rates did not always cause a stimulation of motility. Low infusion rates generally caused an increase in the amplitude of contractions without any effect on basal oviductal tone. The higher infusion rates usually caused a large increase in basal tone as well as an increase in the amplitude of contractions. Ova were recovered from the oviducts of five patients who had received an intravenous infusion of 15(S)-15methyl PGF2alpha. The ova were recovered from the ampulla in three patients, from the ampullary-isthmic junction in one patient, and from the isthmus in one patient. Since one would expect to recover ova from the oviducts at similar times under normal circumstances, there was no evidence that this prostaglandin treatment caused an acceleration of ovum transport. These data support the conclusion that a PGF analog which stimulates oviductal motility does not necessarily also accelerate ovum transport in women.

Temporal relationships of estrogen, progesterone, and luteinizing hormone levels to ovulation in women and infrahuman primates.

These studies were undertaken to ascertain the interval between the estrogen and LH peaks and ovulation in women, rhesus monkeys, and baboons. Estrogen, progesterone, and LH were measured by RIA. Ovulation was documented by visual examination of the ovaries, histology of the corpora lutea, and recovery of ova. The data for human subjects was based on a group of 23 normal women scheduled for surgical sterilization. Blood was drawn daily between 8:30 and 10:30 P.M. beginning on day 10 of the cycle. Surgery was performed 1 to 5 days after the LH peak. The hormonal findings were correlated with the histology of the corpus luteum. The mean interval from the estrogen peak to ovulation was 34 hours, the interval from the estrogen peak to the LH peak was 24 hours, and that from the LH peak to ovulation was 9 hours. In 46 rhesus monkey cycles and in 53 baboon cycles diagnostic serial laparoscopic examinations were initiated following the estrogen peak and repeated every 24 hours until ovulation was confirmed. The mean interval between the estrogen peak and ovulation was 34 hours in the monkey and 41 hours in the baboon. The intervals from the estrogen peaks to the LH peaks were 12 hours in the monkey and 23 hours in the baboon. The intervals from LH peak to ovulation were 22 hours in the monkey and 18 hours in the baboon. Plasma progesterone levels were significantly increased prior to the LH peak in all three species.

The secretion of progesterone during the periovulatory period in women with certified ovulation.

A pre-LH peak rise of progesterone in peripheral blood has been found in 13 normal cycling women whose ovulation was confirmed by biopsy of the corpus luteum through serial determination of progesterone and LH performed every 8 h during the periovulatory period. The progesterone rise began as an average 22 h (16-40 h) prior to the LH peak. The maximal preovulatory rise took place 9.6 h (0-24 h) before the LH zenith, remaining low for approximately 17 h when an abrupt rise of progesterone took place. The progesterone peak was detected in the morning samples in 11 of 13 patients studied. The progesterone rise was always followed by an LH peak and the highest peak of progesterone was trailed by the highest LH peak in all the patients except one.

A seven-cell human egg recovered from the oviduct.

A seven-cell human egg recovered from the proximal middle quarter of the oviduct is described. Whether or not it is a normal representative of this stage of human development cannot be established at the present time. The specimen was recovered 83 hours after intercourse and 77 hours after the first significant elevation of the luteinizing hormone level in the urine. According to these data and the results of the endometrial and corpus luteum biopsies, the age of the egg was estimated to be approximately 72 hours. An analysis of size and the reaction of the blastomeres to toluidine blue suggests that they already show some differentiation at this early stage of development. The addition of these findings to previous reports of eggs recovered from human oviducts and uteri gives support to the concept that human eggs are delivered to the endometrial cavity when they contain between 7 and 12 blastomeres.

Attempts to programme ovulation with exogenous oestrogens and LH-RH analogue.

An attempt was made to programme ovulation in women on a predetermined day of the menstrual cycle by treatment used to induce ovulation in anovulatory sterility. At laparotomy for elective sterilization the ovaries were observed to assess the occurrence of ruptured follicles and ovulation. Histological analysis of ovaries and endometrium was performed, and ova were recovered from some women. Several regimens were tested but ovulation seldom occurred as planned. Clomiphene citrate, human chorionic gonadotrophin (HCG), synthetic luteinizing hormone releasing hormone (LH-RH), and ethinyloestradiol were ineffective. Human menopausal gonadotrophin followed by HCG was more effective, but multiple ovulations occurred. When one single injection of a potent long-acting LH-RH analogue was given on day 13 of the cycle to 10 women pretreated with ethinyloestradiol signs of recent ovulation were observed on day 15 in seven and on day 16 in two.