Direct evidence of estrogen modulation of pituitary sensitivity to luteinizing hormone-releasing factor during the menstrual cycle.
(17/317)
To delineate the role of estradiol in the augmented pituitary gonadotropin responsiveness to synthetic luteinizing hormone releasing factor (LRF) seen during high-estrogen phases of the ovulatory cycles (late follicular and midluteal phases), the anti-estrogenic effect of clomiphene citrate (Clomid) on pituitary response to LRF was evaluated during different phases of the ovulatory cycle. Clomid administration (100 mg/day times 5 days) completely negates the augmented gonadotropin responses to LRF (150 mug) during late follicular and midluteal phases observed during the control studies. Thus, a quantitatively and qualitatively similar pituitary sensitivity to LRF during three distinct phases of the menstrual cycle was induced by Clomid treatment that resembles the LRF responsiveness of themale pituitary. The present study demonstrates the pituitary component of the estrogen-induced changes in the sensitivity to LRF. From this and previous data, we conclude that the increases of estradiol secretion associated with the follicular maturation and corpus luteum formation represent a major component of the feedback signal in the modulation of cyclic gonadotropin release occasioned in a large measure by the augmented pituitary sensitivity to LRF. (+info)
Use of clomiphene and luteinizing hormone/follicle stimulating hormone-releasing hormone in investigation of ovulatory failure.
(18/317)
A luteinizing hormone/follicle-stimulating hormone-releasing hormone (LH/FSH-RH) test was performed in 70 women with amenorrhoea or anovulatory infertility, or both, and a clomiphene stimulation test was also performed in 24 of these patients. Most patients responded to LH/FSH-RH with significant increases in LH and FSH. In women with gonadal dysgenesis or premature ovarian failure exaggerated responses were observed after LH/FSH-RH and there was no change in high basal LH levels after clomiphene. Patients with absent or impaired responses to LH/FSH-RH failed to respond to clomiphene. All patients with anovulatory menstrual cycles responded to both LH/FSH-RH and clomiphene, while seven out of 13 amenorrhoeic patients with a normal LH/FSH-RH response showed an early LH rise during clomiphene treatment and six were unresponsive. These results suggest a difference between the two groups at hypothalamic level with consequent therapeutic implications. (+info)
Effect of clinical and semen characteristics on efficacy of ovulatory stimulation in patients undergoing intrauterine insemination.
(19/317)
PURPOSE: We measured the effect of ovulatory stimulation (OS) upon intrauterine insemination (IUI) success rates, particularly among patients with risk factors for IUI failure. METHODS: Retrospective review of medical and laboratory results from 512 patients who underwent 1576 cycles of IUI with partner's sperm over a 3 year period. Data were collected on 3 risk factors for IUI failure (advanced female age > 37.7 years, prior corrective pelvic surgery, and poor post-wash sperm motility), and on method of OS (none, clomiphene citrate, or gonadotropin). RESULTS: Patients who underwent OS had significantly higher pregnancy rates (7.6%) than those who did not (4.7%, p = 0.02). However, when patients were stratified by their risk factors, OS made a significant difference only for patients without risk factors. These patients had a 15.5% per cycle pregnancy rate with OS, compared to 7.9% in unstimulated IUI cycles (p = 0.04). CONCLUSIONS: Ovulatory stimulation doubles IUI pregnancy rates among young patients without a prior pelvic surgery and with good post-wash semen quality. The benefit of OS for patients with risk factors for IUI failure is unclear. These patients should be counseled that their chances for success with IUI are limited, with or without OS. (+info)
Attempts to programme ovulation with exogenous oestrogens and LH-RH analogue.
(20/317)
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. (+info)
Assessing the status of intrauterine insemination before forming a medically assisted conception unit.
(21/317)
A survey in 1996 of our female patients suggest that the three commonest causes of infertility were endometriosis, anovulation and idiopathic which comprises of about 70% of all the patients. In the male patients, sperm morphology evaluation by critical criteria showed that abnormal morphology was present in 71% while 87% of all the semen analysis were abnormal. The objective of this study was to assess the status of IUI before proceeding to formulate patient protocols for IVF in a tertiary infertility referral unit. A retrospective study of patients data was done from Jan 1995 to Dec 1996. Ovarian stimulation by clomiphene for anovulatory and idiopathic patients was performed on couples with at least one patent fallopian tube. Ovulation induction was by an intramuscular injection of 5000 i.u of HCG after follicular maturation. IUI was performed approximately 36-40 hours later. A total of 74 couples received 114 treatment cycles producing a total of 9 conceptions. The conception rate of IUI was therefore 7.89% per cycle and 12.16% per couple with the cumulative pregnancy rate of 28.21%. Associated success features of IUI found in this study were the age of the woman and the semen parameters of the husband. (+info)
The prognostic value of age and follicle-stimulating hormone levels in women over forty years of age undergoing in vitro fertilization.
(22/317)
PURPOSE: Basal follicle-stimulating hormone (FSH) and age are predictors of successful outcome in in vitro fertilization (IVF). More recently, the clomiphene citrate challenge test (CCCT) has been proposed as a better way to predict IVF outcome than FSH alone. The purpose of this study was to determine which indicator of ovarian reserve--basal (day 3) FSH or the CCCT--is the better predictor of IVF success in the critical age group of women over the age of 40. METHODS: In this retrospective study, basal FSH and clomiphene-stimulated FSH levels from 104 women who underwent 175 cycles of IVF were analyzed. RESULTS: Neither basal FSH level nor stimulated FSH level alone were statistically significant predictors of IVF success; however, no patient with a day 3 FSH level > 11.1 mIU/ml or a stimulated day 10 FSH level > 13.5 mIU/ml conceived and carried a pregnancy. All ongoing pregnancies occurred in the first two cycles of IVF. CONCLUSIONS: Clear prognostic cutoff values were found to predict IVF success in women over age 40. IVF programs should consider limiting the number of cycles of IVF in women above age 40. (+info)
Estrogen modulation of gonadotrophin release.(23/317)
Clomiphene citrate increases insulin-like growth factor binding protein-1 and reduces insulin-like growth factor-I without correcting insulin resistance associated with polycystic ovarian syndrome.
(24/317)
The induction of ovulation by clomiphene could be the result of interaction of the drug at various levels: hypothalamus, pituitary and ovary. It was demonstrated that administration of clomiphene to women with polycystic ovarian syndrome (PCOS) is accompanied by a reduction in plasma concentrations of insulin-like growth factor-I (IGF-I). IGF-I seems to have an overall negative effect on normal folliculogenesis and ovulation. The aim of the present study was to evaluate the effect of clomiphene on plasma concentrations of IGF-I and IGF binding protein (IGFBP)-1 and on insulin resistance associated with PCOS. Fifteen patients diagnosed with PCOS were recruited. Clinical diagnosis was based on chronic oligomenorrhoea or amenorrhoea and hyperandrogenaemia. Clomiphene citrate was administered at a dose of 100mg/day to all women from day 5 to day 9 of the spontaneous or medroxyprogesterone acetate (MAP)-induced menstrual cycle. Blood sampling and a 2 h oral glucose loading test (75 g) were performed the day before and after the course of clomiphene. Ovulation was confirmed in 13/15 PCOS patients. Plasma concentrations of IGF-I decreased by 31.5% (434 +/- 84 versus 297 +/- 71 ng/ml; P: < 0.05) after 5 days of clomiphene therapy, whereas plasma concentrations of IGFBP-1 increased by approximately 28.1% (26.3 +/- 4 versus 36.6 +/- 7 ng/ml; P: < 0.05). This gave a 56.5% reduction in the IGF-I:IGFBP-1 ratio (21.9 versus 9.53). No significant changes in basal plasma concentrations of fasting insulin or area under the insulin curve were observed in response to oral loading. The present results show that clomiphene does not cause changes in insulin resistance associated with PCOS but reduces plasma concentrations of IGF-I and increases those of IGFBP-1, with a consequent marked reduction in the IGF-I:IGFBP-1 ratio. (+info)