Further observations on the therapy of anovulatory infertility with synthetic luteinizing hormone-releasing hormone

Five decades of progress in management of the infertile couple

OBJECTIVE

To review milestones in the care of the infertile couple over the past five decades.

DATA RESOURCES

All issues of Fertility and Sterility were reviewed beginning with the first issue published in 1950 through volume 61, number 1 (January 1994). Other significant articles from the literature were reviewed as identified by directed Medline searches.

RESULTS

This historical review gives the reader a sense of the evolution of modern reproductive technology--how the past has shaped the present--through the development of modern surgical techniques, methods of ovulation induction, laparoscopy, ultrasound, endocrine assays, in vitro fertilization, cryopreservation of sperm and preembryos, and microscopic procedures on gametes and preembryos.

CONCLUSIONS

The remarkable capabilities of modern reproductive technologies are only possible because of the culmination of decades of innovative research.

Comparison of pituitary response to regular GnRH, analogue (D-TRP6) and placebo

Pituitary response to synthetic regular GnRH, to a potent analogue (D-TRp6) and to placebo were compared in ten azoospermic males. FSH and LH were measured prior to and at given intervals following administration of each substance. In addition, plasma levels of testosterone and prolactin were measured. There was no significant difference in the magnitude of FSH and LH release following injection of their the regular or the analogue form of GnRH. However, plasma gonadotrophins remained elevated for significantly longer time periods following the administration of the analogue GnRH. In those patients in whom LH levels remained elevated for at least 24 hours the observation of elevated testosterone levels permitted the inference of adequate biological activity of endogenously produced LH. Patients who did not respond to the regular GnRH were also non-responsive to D-TRp6 GnRH. A surprising finding ws elevated prolactin levels 4-6 hours following GnRH administration. Placebo had no influence on gonadotrophins, testosterone and prolactin.

Ovulation induction with luteinizing hormone--releasing hormone in amenorrheic, infertile women

Thirteen women with infertility thought due to anovulation were treated with LRH. Etiologic diagnoses of amenorrhea included hypothalamic or "idiopathic" and PCOD. All patients had normal gonadotropins and otherwise normal endocrinologic and infertility evaluations; none had ovulated with clomiphene. Patients were studied for six 35 day cycles, single blind, and received LRH or placebo by subcutaneous injections for 28 days/cycle (LRH dosage 1.0 mg 2 or 3 times each day). Frequent assessments of physical status, cervical mucus, vaginal cytology, and serum LH, FSH, estrogen, and progesterone were performed. Ovulation was documented by basal temperature, serum progesterone and, on occasion, endometrial biopsy. Follow-up was continued for 6 months after therapy. Of the 13 patients treated, eight have ovulated and five have conceived. There were no complications of therapy.

Monitoring of ovulation induction

The plasma hormonal patterns of the normal menstrual cycle have been reviewed. A consistent cyclic pattern of plasma hormone levels is observed in LH, FSH, estrogens, and progestins in the menstrual cycle. Other plasma hormones, such as ACTH, growth hormone, TSH, and PRL, as well as androgens and corticosteroids, fluctuate throughout the menstrual cycle without any consistent pattern during the ovulatory cycle. FSH, LH, E2, E1, P, T, and A levels during the induced ovulatory cycle are presneted for comparison. In the gonadotropin-induced ovulatory cycle most hormones behave in a manner similar to that in the normal ovulatory cycle, except for FSH levels, which rise continuously throughout the follicular phase of the cycle. Following ovulation in the gonadotropin-induced cycle, T rises above normal levels. Early in the clomiphene-induced ovulatory cycle, unlike the normal cycle, LH is distinctly elevated. Levels of both LH and FSH in the rest of the cycle simulate those in the normal cycle. However, T and A levels rise from the very beginning of clomiphene therapy and continue to rise throughout the clomiphene-induced ovulatory cycle. Levels of E and P are higher than in the normal ovulatory cycle, but a similar pattern is preserved. Because of the potential dangers of gonadotropin therapy, monitoring by frequent examination and laboratory tests is required. E monitoring is mandatory to evaluate follicular maturation, to time hCG administration, and to minimize hyperstimulation. Cervical mucus is an unreliable parameter for monitoring gonadotropin therapy alone. In addition to cervical mucus, plasma or urinary E should be monitored regularly. Clomiphene therapy is less dangerous than gonadotropin therapy. Because of its lesser risk, monitoring is rarely performed during clomiphene use. An active monitoring approach has been described. While this approach may not necessarily improve the outcome of clomiphene therapy, it may hasten the process of selecting the appropriate dose. Although other ovulation-inducing agents are available, their use is rarely associated with serious medical complications, and monitoring would seem unnecessary.

Hormonal and clinical responses in amenorrhetic patients treated with gonadotropins and a nasal form of synthetic gonadotropin-releasing hormone

Synthetic gonadotropin-releasing hormone (GnRH) in the form of nasal drops was self-administered by five amenorrheic patients in an attempt to assess its therapeutic value in anovulatory infertility. After follicular maturation had been induced with human menopausal gonadotropins (HMG), a total daily dose of 7.5 mg of GnRH in the form of nasal drops was self-administered at 2-hour intervals for 6 hours on 3 consecutive days. In four patients, plasma luteinizing hormone (LH) levels were significantly elevated over a period of at least 8 hours. In three of these patients, in addition, there was a definite upward shift in the basal body temperature (BBT) curve, and uterine bleeding occurred 6 to 9 days after the first dose of GnRH. In the fourth patient, ovulation was induced as indicated by a biphasic BBT curve, a plasma progesterone level of 13 ng/ml, and a luteal phase of 15 days. In the remaining patient, there was a borderline LH response and no clinical response. It is concluded that GnRH, in the form of nasal drops, is effective in eliciting and maintaining elevated plasma LH levels in patients in whom follicular maturation has been induced with HMG. By obtaining ovulatory LH levels, such a regimen can lead to ovulation. In addition, intranasal self-administration of GnRH is convenient and may provide an alternative route of administration for long-term therapy with this hormone.

Therapeutic use of gonadoliberin (follicle-stimulating hormone/luteinizing hormone-releasing hormone) in women

Certain conclusions may be drawn from the present review: 1. Synthetic FSH/LH-RH may induce ovulation; therefore, a therapeutic effect has been established in some cases of anovulatory infertility, but it is still difficult to assess the correct dose of FSH/LH-RH because of individual variations in response. 2. Gonadoliberin may also be used to induce ovulation after follicular maturation has been evoked by other agents. FSH/LH-RH can be utilized for supplementing the LH surge after clomiphene therapy in cases of clomiphene failure. When associated with HMG, the synthetic decapeptide may be helpful in avoiding the ovarian hyperstimulation syndrome. 3. The "triggering" of ovulation by a continuous infusion of FSH/LH-RH might be a convenient means of controlling the timing of ovulation. 4. It is expected that FSH/LH-RH blocking analogs may be used to inhibit both LH and FSH release induced by endogenous gonadoliberin in women seeking contraception.

Luteinizing hormone-releasing hormone for induction of follicular maturation and ovulation in women with infertility and amenorrhea

Five patients with primary infertility and secondary amenorrhea who did not respond to clomiphene with a gonadotropin or estrogen surge were treated with 500 mug of luteinizing hormone, follicle-stimulating hormone-releasing hormone (LH-RH), self-administered subcutaneously every 8 hours for 14 days. Of four patients who responded to this treatment, three showed follicular maturation, ovulation, and menses, although the luteal phase was deficient; in the fourth patient, follicular maturation and menses occurred without evidence of ovulation. For their second course of treatment these four patients were given LH-RH with the addition of human chorionic gonadotropin when the urinary estrogen levels indicated follicular maturation. All four patients responded with ovulation, an adequate luteal phase, and menses, without clinical indication of ovarian hyperstimulation. These results suggest that LH-RH may be a better alternative to human menopausal gonadotropin in the treatment of anovulatory infertility.

Serum estradiol response to gonadotropin-releasing hormone: studies in normal women and in women with secondary amenorrhea

Serum estradiol (E2), luteinizing hormone (LH), and follicle stimulating hormone (FSH) levels were measured in blood samples obtained prior to and at frequent intervals for 360 or 480 minutes following the subcutaneous administration of gonadotropin releasing hormone (Gn-RH) to eight normal women and nine patients with hypothalamic secondary amenorrhea. In the normal subjects given 100 mug of Gn-RH on day 7 of the menstrual cycle, there was no significant increase in the mean E2 concentration above basal levels. Six women with secondary amenorrhea received Gn-RH, 100 mug, for 4 successive days; frequent blood samples were obtained on days 1 and 4. On day 1, the mean E2 concentration at 360 minutes was significantly greater than the mean basal level. On day 4 no significant increase in E2 was detected, although the mean LH and FSH responses and basal E2 level were not different from those of day 1. Four women with secondary amenorrhea received daily doses of 500 mug of Gn-RH for 7 days. Significant increases in mean serum E2 concentration (100 to 150 pg/ml) were noted at 6 and 8 hours after administration on day 1 and at 8 hours on day 4. No significant rise in E2 was detected on day 7. The mean LH and FSH responses did not differ from those observed in women who received the 100-mug dose, and there were no significant differences in responses on successive days of Gn-RH administration.

Increased and prolonged LH-RH/FSH-RH activity of synthetic (D-Ala6, Des-Gly-NH210)-LH-RH-ethylamide in normal women

A synthetic LH-RH analogue (D-Ala6, Des-Gly-NH210)-LH-RH ethylamide exhibited an increased and prolonged LH-RH/FSH-RH activity in normal women. The integrated amounts of LH and FSH levels for this LH-RH analogue were about nine and five times greater than for the same doses of synthetic LH-RH. It is expected that this synthetic LH-RH analogue might yield more positive results than with LH-RH when used in infertility problems.

D-norgestrel slow-releasing T device as an intrauterine contraceptive

A D-norgestrel slow-releasing T device was tried as an IUD in 100 fertile multiparous women for 6 months. The preliminary results were very encouraging. Not a single case of unintended pregnancy or removal due to excessive pain and bleeding was reported. The menstrual patterns and amounts of blood loss during menses did not reveal any marked variations. 3-H-D-norgestrel was used to study the in vitro release rate of D-norgestrel. The in vivo release rate was studied with the use of horseshoe-shaped silicone rubber capsules loaded with D-norgestrel as a temporary device. The uptake of intrauterine H-D-norgestrel in the circulation and genital tissues was estimated in two women.

Gonadotropin-releasing activity of two highly active and long-acting analogs of luteinizing hormone-releasing hormone after subcutaneous, intravaginal, and oral administration

The gonadotropin-releasing activities of two synthetic analogs of luteinizing hormone-releasing hormone (LH-RH), D-Ala6-des-Gly10-LH-RH ethylamide and D-Leu6-des-Gly10-LH-RH ethylamide were evaluated in immature female rats after subcutaneous, intravaginal, and oral administration. Maximal peaks of serum LH and follicle-stimulating hormone (FSH) levels after administration of both analogs by any of the three routes were obtained at 2 hours. Therefore, serum gonadotropin levels declined slowly, so that at 6 hours LH levels had returned to base line values, whereas FSH levels remained elevated for up to 10 hours. The integrated serum gaondotropin levels after LH-RH and both analogs over a 10-hour period indicated that D-Leu6-des-Gly10-LH-RH EA and D-Ala6-des-Gly10-LH-RH EA released more LH and FSH than did the LH-RH decapeptide. The intense and long-acting properties of these analogs in releasing LH and FSH suggest the possibility that they may be more useful therapeutically than LH-RH.

Gonadotrophin-releasing hormone treatment for induction of follicular maturation and ovulation in amenorrhoeic women with anorexia nervosa

Follicular maturation and ovulation can be induced in amenorrhoeic women with anorexia nervosa by long-term treatment with 500 mug of luteinizing hormone releasing hormone (LH-RH) every eight hours. In some women, however, treatment with LH-RH alone results in ovulatory menstrual cycles with indications of luteal phase insufficiency. Human chorionic gonadotrophin (HCG) was therefore given with LH-RH during three treatment cycles. This resulted in ovulation and normal corpus-luteum function, as shown by the occurrence of a single pregnancy in the only involuntarily sterile patient. During the prolonged LH-RH treatment the LH response to LH-RH increased in parallel with the increased oestrogen secretion while the follicle-stimulating hormone response to LH-RH decreased. These changes in the pituitary responsiveness to LH-RH may result from modulating effects on the pituitary by the sex steroids.

Successful induction of follicular maturation and ovulation by prolonged treatment with LH-releasing hormone in women with anorexia nervosa

Four women with anorexia nervosa were treated with synthetic LH-releasing hormone (LRH) in an attempt to induce ovulation. All the women had very low pretreatment levels of gonadotropins and estrogens. Administration of LRH resulted in significant gonadotropin increases. The FSH response to LRH in relation to the LH response was higher than in regularly menstruating women. LRH (500 mug) was administered parenterally three times daily over about 4 weeks. During this period there were no significant effects on mood, eating behavior, weight, or libido. All the women responded with follicular maturation and ovulation to the prolonged LRH treatment.

Induction of timed ovulation with synthetic luteinizing hormone-releasing hormone in women undergoing insemination therapy. I. Effect of a single parenteral administration at midcycle

Synthetic LH-RH was administered by various routes to 19 patients during 37 treatment cycles in an attempt to trigger ovulation in association with insemination therapy. Thirty-five cycles were ovulatory; four pregnancies occurred, but two of them ended in spontaneous abortion. In 20 cycles, the hyperthermia response occurred one to three days after LH-RH administration, suggesting that ovulation occurred as a direct consequence of administered LH-RH. Low levels and delayed peak secretion of progesterone were found in two patients who had serial progesterone determinations during the luteal phase after LH-RH administration. Ovulation timing with LH-RH appears feasible, but efforts to ensure the availability of a mature follicle are required.