Suppression of ovulation with human chorionic gonadotropin

Postpartum anovulation in non-nursing monkeys: hypothalamic-pituitary-ovarian refractoriness is not induced by the milieu of early pregnancy

To evaluate the role of the early pregnancy milieu in inducing postpartum refractoriness of the hypothalamic-pituitary-ovarian axis, pregnancies in rhesus monkeys were terminated on either day 35 of gestation or near term at 162 days. Non-nursing mothers with gestations interrupted near term resumed ovulation at a mean of 56 +/- 12 (mean +/- SE) days postpartum, in contrast to the 17 +/- 2 days required for the females having had abortions at day 35. These results demonstrate that the early pregnancy milieu is not determinant of the hypothalamic-pituitary-ovarian refractoriness observed in non-nursing mothers delivering at term.

A prospective randomized study of the optimum timing of human chorionic gonadotropin administration after pituitary desensitization in in vitro fertilization

OBJECTIVE

To determine if there is an optimum time for the administration of human chorionic gonadotropin (hCG) after pituitary desensitization with gonadotropin-releasing hormone agonists (GnRH-a) has been achieved before ovarian stimulation for in vitro fertilization (IVF).

DESIGN

Prospective randomized study.

PATIENTS

Two hundred forty-seven patients undergoing an IVF treatment cycle who were randomly divided into three groups.

INTERVENTIONS

All patients were administered subcutaneously buserelin acetate 500 micrograms/d from day 1 of the menstrual cycle. After pituitary desensitization had been achieved at least 14 days later, ovarian stimulation with human menopausal gonadotropin was commenced. Ovarian stimulation, cycle monitoring, oocyte recovery, and IVF and embryo transfer (ET) techniques were identical in all three groups. Patients in group 1 (n = 79) had hCG administered when the mean diameter of the largest follicle had reached 18 mm, at least two other follicles were greater than 14 mm, and serum estradiol (E2) levels were consistent with the number of follicles observed on ultrasound. Patients in groups 2 (n = 84) and 3 (n = 84) had hCG administered 1 day and 2 days, respectively, after the above criteria had been reached.

RESULTS

The mean day of hCG administration (P less than 0.01), maximum serum E2 concentration (P = 0.06), number of days of serum E2 rise (P = 0.03), and mean diameter of the largest follicle (P less than 0.0001) were significantly different. There were, however, no significant differences in the mean number of preovulatory and medium size follicles, number of oocytes recovered or embryos transferred. There were also no significant differences in the oocyte recovery, fertilization and cleavage rates, in the number of embryos frozen, or in the pregnancy rates per initiated cycle and per ET.

CONCLUSIONS

There is no significant advantage in the precise timing of hCG administration after pituitary desensitization with GnRH-a.

Polycystic ovarian disease: endocrinological parameters with specific reference to growth hormone and somatomedin-C

Thirty-three women (22-38 years old) with polycystic ovarian disease (PCOD) were included in this study. The criteria for diagnosis were: an LH/FSH ratio greater than 2.0; polycystic ovaries, diagnosed by means of palpation and ultrasound; androgenism and menstrual cycle abnormalities. Using endocrine parameters, we attempted to define distinct forms of PCOD. The patients were placed in three groups according to serum levels of testosterone (T) and 17 alpha-hydroxyprogesterone (17 alpha OHP) and the estrone/androstendione (E1/delta 4A) ratio. Patients in group I (n = 18) had an elevated T level (greater than 1.0 ng/ml) and a 17 alpha OHP level under 4.0 ng/ml. This type of POCD was called the "androgen" type. Patients in group II (n = 7) had normal T- and 17 alpha OHP levels under 4.0 ng/ml and an elevated (E1/delta 4A) ratio. This type of PCOD was called the "estrogen" type. Group III (n = 8) comprised patients with 17 alpha OHP levels over 4.0 ng/ml. This type of PCOD was called the "adrenocortical" type. In two patients of this group, a modified ACTH test revealed late-onset congenital hyperplasia. The endocrine parameters of the patients with PCOD were compared with those of 17 adult without signs of PCOD. Statistical evaluation was done by variance analysis. Women with acromegaly often show signs of androgenism as well as menstrual cycle abnormalities. This may indicate an association between the growth factors human growth hormone (HGH) and somatomedin-C (Sm-C) and the biosynthese and metabolism of steroid hormone. Recent experiments have demonstrated such associations. Our study showed an association between the HGH and Sm-C levels and abnormal steroid hormone concentrations in women with androgen type PCOD (group I). These patients had a significantly decreased HGH level, a significantly decreased HGH/Sm-C ratio, and an increased average Sm-C level. These data suggest that elevated Sm-C levels can, by a negative-feedback mechanism, inhibit pituitary HGH production. We discuss the possible mechanisms causing elevation of plasma Sm-C, HGH, steroid hormones, excessive food intake, and possibly prolactin seem responsible for the clinical manifestation of increased Sm-C production in adolescence and for its level in the fertile years of patients.

Delaying human chorionic gonadotropin administration in human menopausal gonadotropin-induced cycles decreases successful in vitro fertilization of human oocytes

Correct timing of human chorionic gonadotropin (hCG) administration in induced cycles for in vitro fertilization is of crucial importance to oocyte maturation and normal luteal function. The purpose of this work was to compare the effect of hCG timing on follicular development, oocyte maturation, and fertilization in vitro, as well as on the pattern of luteal phase hormone secretion. Ovulation was induced in 32 normally cycling women by human menopausal gonadotropin (hMG)/hCG administration. In the first group (17 women) 10,000 IU hCG was administered 24 hours after the last injection of hMG and in the second group (15 women) 48 to 72 hours after the last hMG injection. Serum estradiol levels prior to oocyte aspiration were similar in both groups, as were the numbers of large follicles on the day of hCG administration (4.5 +/- 2.3 versus 4.1 +/- 1.9 follicles/woman, respectively). The distribution of oocyte-corona-cumulus complexes was similar in both groups and was comprised of 11% immature, 43% intermediate, and 45% mature complexes. The fertilization rate, however, was significantly (P less than 0.001) reduced in the group treated by delayed hCG injection (57% versus 84%), and the percentage of degenerated oocytes was increased (9% versus 1%). Luteal phase length as well as progesterone and estradiol levels were comparable in both groups. It is concluded that an interval longer than 24 hours between the last injection of hMG and the administration of an ovulatory dose of hCG does not affect follicular and luteal phase serum steroid patterns but may result in a decreased oocyte fertilization rate, possibly due to atretic changes in the follicles.

Contraception with an LHRH agonist: effect on gonadotrophin and steroid secretion patterns

Chronic treatment with the LHRH agonist D-Ser(TBU)6-LHRH (1-9)-EA (buserelin) has been suggested as a contraceptive method since it has been shown to inhibit ovulation. To elucidate the mechanism of this paradoxical action, we investigated the pattern of gonadotrophin and steroid secretion after the daily intranasal application of 300 micrograms of the agonist. Ten volunteers with ovulatory cycles received the analogue from Day 1 to Day 22 and 5 mg norethisterone acetate from Day 16 to Day 22. Blood samples were taken on Day 1, 15, and 21 every 15 min for 6 h after the application of the agonist. LH secretion was increased nine-fold on the first treatment day as compared to Day 2 of the preceding control cycle. Thereafter, it decreased slowly but was still elevated five-fold on Day 21 of treatment. FSH release increased three-fold on Day 1 but decreased thereafter to values similar to those of the controls. During treatment with the analogue, the LH/FSH ratio changed from 1.3 (controls) to 3.8 on Day 1 and to 5.5 on Day 15 and 21 of treatment. Although the ovary retained follicular activity, ovulation was inhibited in every treatment cycle. This seemed to be due to an impairment of follicular steroid synthesis as indicated by a significant increase of 17 alpha-hydroxyprogesterone and testosterone levels for several hours after the application of the analogue. It appears that at least during the first treatment cycle of daily administration of buserelin the abolishment of pulsatile gonadotrophin release, and the abnormally increased ratio of LH/FSH secretion may possibly impair follicular maturation and thus contribute to the inhibition of ovulation.

Effects of prolonged luteinizing hormone-releasing hormone therapy on follicular maturation, ovulation and corpus luteum function in amenorrhoeic women with anorexia nervosa

Nine amenorrhoeic women with anorexia nervosa (AN) were given long-term treatment with 500 microgram of synthetic luteinizing hormone-releasing hormone (LRH) every 8 h. All the women had impaired luteinizing hormone (LH) secretion and no evidence of endogenous oestrogen production. Three of them also had deficient follicle-stimulating hormone (FSH) secretion. The pituitary reserve capacity for gonadotrophin secretion was normal but the response pattern to LRH was similar to that described in prepubertal girls. The constant administration of LRH normalized basal LH and FSH secretion and induced a cyclical gonadotrophin secretory pattern with differential changes of the LH and FSH responses to LRH during the treatment. LRH-induced gonadotrophin secretion produced follicular growth and maturation in all the women. Presumptive ovulation also occurred during the 8 treatment courses in which only LRH was administered. However, inadequate luteal phases were observed during 6 of these 8 cycles. Combined therapy with LRH and human chorionic gonadotrophin (HCG) during 5 treatment courses resulted in normal ovulatory cycles with adequate corpus luteum function.