克罗米酚对血清雌激素和孕激素水平的影响

目的探讨克罗米酚(CC)在诱发排卵过程中对雌、孕激素水平的影响。方法采用放射免疫法,测定16例不明原因不孕妇女在自然周期和用药周期的排卵前1天和排卵后10天血清雌二醇(E2)和孕酮(P)浓度。结果排卵前1天和排卵后10天,用药周期的E2、P浓度均高于自然周期(P<0.05)。结论克罗米酚在诱发排卵过程中可导致内源激素平衡紊乱。     

Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin

To assess the risk of miscarriage after in-vitro fertilization(IVF) with respect to age, cause of infertility, ovarian morphologyand treatment regimen, a retrospective analysis was performedof the first 1060 pregnancies conceived between June 1984 andJuly 1990 as a result of 7623 IVF cycles. Superovulation inductionwas achieved with human menopausal gonadotrophin (HMG) and/orpurified follicle stimulating hormone (FSH) together with eitherclomiphene citrate or the gonadotrophin hormone-releasing hormone(GnRH) agonist buserelin, the latter either as a short ‘flare’regimen or as a ‘long’ regimen to induce pituitarydesensitization. There were 282 spontaneous abortions (26.6%)and 54 ectopic pregnancies (5.1%). The mean age of women withongoing pregnancies was 32.2 (SD 3.9) years compared with 33.2(SD 4.1) years in those who miscarried, which were significantlydifferent (P = 0.008). There was no relation between the miscarriagerate and the indication for IVF. The miscarriage rate was 23.6%in women with normal ovaries compared with 35.8% in those withpolycystic ovaries [P = 0.0038, 95% confidence interval (CI)4.68–23.10%]. There was no difference in the miscarriagerate between treatment with HMG or FSH. Women whose ovarieswere normal on ultrasound were just as likely to miscarry ifthey were treated with clomiphene or with the long buserelinprotocol. Those with polycystic ovaries, however, had a significantreduction in the rate of miscarriage when treated with the longbuserelin protocol, 20.3% (15/74), compared with clomiphenecitrate, 47.2% (51/108) (P = 0.0003, 95% CI 13.82–40.09%).     

Ovarian stimulation by clomiphene citrate and hMG in combination with cetrorelix acetate for ICSI cycles

BACKGROUND: The introduction of GnRH antagonists such as cetrorelix acetate has made possible the simplification of ovarian stimulation. However, the most effective protocol for their administration has not yet been clearly defined. METHODS: Forty women with male-factor infertility undergoing 40 ICSI cycles were included in the study. Clomiphene citrate at 100 mg a day was given from cycle day 3 through day 7. hMG at 150 IU was given on cycle days 4, 6 and 8, and was adjusted from day 9 according to the follicular and hormone responses. Cetrorelix acetate at 2.5 mg was administered when the leading follicle reached 14 mm. The remaining 0.5 mg was divided into two 0.25 mg injections for possible later use. Serum FSH, LH, estradiol and progesterone levels were measured daily from the day of cetrorelix acetate injection until hCG was given. RESULTS: Serum LH level was suppressed effectively for 4 days. Four patients (10%) needed one or two additional injections of 0.25 mg cetrorelix acetate. No premature LH surge was detected in any of the women treated. Sixteen women became pregnant (40%), of which 14 pregnancies (35%) were ongoing at the time of writing. CONCLUSIONS: This study demonstrates that this new protocol is feasible for couples with male-factor infertility undergoing ICSI.     

Effects of enclomiphene and zuclomiphene on basal and gonadotrophin-stimulated progesterone secretion by isolated subpopulations of small and large ovine luteal cells

We examined the effects of enclomiphene and zuclomiphene, aloneand in combination with oestradiol, on basal and gonadotrophin-stimulatedprogesterone secretion by isolated subpopulations of both large(granulosa-lutein) and small (theca-lutein) ovine luteal cells.Isolated large and small luteal cells derived from intact, enucleatedovine corpora lutea were incubated for 48–120 h with orwithout 22R-hydroxycholesterol or pregnenolone (2.5 µM)and a range of enclomiphene, zuclomiphene, and/or oestradiolconcentrations (3–100 µM), both with and withoutovine Iuteinizing hormone (100 ng/ml). Spent media were assayedin duplicate for progesterone content by radioimmunoassay. Enclomiphene,zuclomiphene, and oestradiol exhibited equivalent dose-dependentinhibitory effects on basal and gonadotrophin-stimulated smalland large ovine luteal cell progesterone secretion under allsubstrate conditions. Both cell types became more sensitiveto clomiphene inhibition with increasing time in culture. Incombined treatments, the effects of oestradiol and either enclomipheneor zuclomiphene became additive in longer-term cultures andwere never antagonistic In this model system, (i) clomiphene,like oestradiol, appears to inhibit 3-hydroxysteroid dehy-drogenaseactivity, (ii) both stereoisomers act as oestrogen agonists,(iii) neither demonstrates any anti-oestrogenic properties,and (iv) both large and small luteal cells become more sensitiveto clomiphene inhibition with increasing duration of exposure.     

Intrauterine insemination treatment in subfertility: an analysis of factors affecting outcome

A total of 811 intrauterine insemination (IUI) cycles in which clomiphene citrate/human menopausal gonadotrophin (HMG) was used for ovarian stimulation were analysed retrospectively to identify prognostic factors regarding treatment outcome. The overall pregnancy rate was 12.6% per cycle, the multiple pregnancy rate 13.7%, and the miscarriage rate 23.5%. Logistic regression analysis revealed five predictive variables as regards pregnancy: number of the treatment cycle (P = 0.009), duration of infertility (P = 0.017), age (P = 0.028), number of follicles (P = 0.031) and infertility aetiology (P = 0.045). The odds ratios for age < 40 years, unexplained infertility aetiology (versus endometriosis) and duration of infertility < or = 6 years were 3.24, 2.79 and 2.33, respectively. A multifollicular ovarian response to clomiphene citrate/HMG resulted in better treatment success than a monofollicular response, and 97% of the pregnancies were obtained in the first four treatment cycles. The results indicate that clomiphene citrate/HMG/IUI is a useful and cost-effective treatment option in women < 40 years of age with infertility duration < or = 6 years, who do not suffer from endometriosis.     

A paradoxical decline in semen parameters in men treated with clomiphene citrate: A systematic review

Clomiphene, a selective oestrogen receptor modulator, has been utilised in managing male sub-fertility since 1967. Numerous controlled and uncontrolled studies have been published regarding the efficacy of clomiphene citrate in male sub-fertility cohorts. Although the primary intention of treating men with clomiphene citrate is to improve sperm parameters and testosterone levels, some studies have reported paradoxical decline in semen parameters. The information available on decline in sperm parameters following treatment with clomiphene is sparse. We conducted a systemic review using PubMed, Embase, Cochrane Library and Scopus databases for original studies reporting adverse effects of clomiphene citrate therapy on sperm parameters. This systematic review includes 384 men from 11 different studies that reported adverse effects of clomiphene citrate therapy. Of the men included in these studies, 19%, 21%, 17% and 24% of clomiphene-treated men demonstrated a decrease in sperm count, concentration, motility and total motile sperm count respectively. In up to 17% of patients, deterioration of semen parameters did not recover following discontinuation of therapy. In the future, more studies should report on this aspect so the magnitude of this effect can be more clearly understood.     

Aromatase inhibition reduces gonadotrophin dose required for controlled ovarian stimulation in women with unexplained infertility

BACKGROUND: Adding clomiphene citrate (CC) to FSH for controlled ovarian stimulation (COS) decreases FSH dose required for optimum stimulation. However, because of its anti-estrogenic effects, CC may be associated with lower pregnancy rates offsetting the FSH-dose reduction benefit. Previously, we reported the success of aromatase inhibition in inducing ovulation without antiestrogenic effects. METHODS: A prospective pilot study that included women with unexplained infertility undergoing COS and intrauterine insemination. Thirty-six women received the aromatase inhibitor letrozole + FSH, 18 women received CC + FSH and 56 women received FSH only. Each woman received one treatment regimen in one treatment cycle. All patients were given recombinant or highly purified FSH (50-150 IU/day) starting on day 3 to 7 until day of hCG. RESULTS: The FSH dose needed was significantly lower in letrozole + FSH and CC + FSH groups compared with FSH-only without a difference in number of follicles >1.8 cm. Pregnancy rate was 19.1% in the letrozole + FSH group, 10.5% in the CC + FSH group and 18.7% in the FSH-only group. Both pregnancy rate and endometrial thickness were significantly lower in CC + FSH group compared with the other two groups. Estradiol (E2) levels were significantly lower in the letrozole + FSH group compared with the other two groups. CONCLUSIONS: Similar to CC, aromatase inhibition with letrozole reduces FSH dose required for COS without the undesirable antiestrogenic effects sometimes seen with CC.     

High affinity of sigma1-binding sites for sterol isomerization inhibitors: evidence for a pharmacological relationship with the yeast sterol C8–C7 isomerase

1. The sigma-drug binding site of guinea-pig liver is carried by a protein which shares significant amino acid sequence similarities with the yeast sterol C₈–C₇ isomerase (ERG2 protein). Pharmacologically - but not structurally - the sigma₁-site is also related to the emopamil binding protein, the mammalian sterol C₈–C₇ isomerase. We therefore investigated if sterol C₈–C₇ isomerase inhibitors are high affinity ligands for the (+)-[³H]-pentazocine labelled sigma₁-binding site.
2. Among the compounds which bound with high affinity to native hepatic and cerebral as well as to yeast expressed sigma₁-binding sites were the agricultural fungicide fenpropimorph (K_i 0.005 nM), the antihypocholesterinaemic drugs triparanol (K_i 7.0 nM), AY-9944 (K_i 0.46 nM) and MDL28,815 (K_i 0.16 nM), the enantiomers of the ovulation inducer clomiphene (K_i 5.5 and 12 nM, respectively) and the antioestrogene tamoxifen (K_i 26 nM).
3. Except for tamoxifen these affinities are essentially identical with those for the [³H]-ifenprodil labelled sterol C₈–C₇ isomerase of S. cerevisiae. This demonstrates that sigma₁-binding protein and yeast isomerase are not only structurally but also pharmacologically related. Because of its affiliations with yeast and mammalian sterol isomerases we propose that the sigma₁-binding site is localized on a sterol isomerase related protein, involved in postsqualene sterol biosynthesis.

     

Ovulation triggering in clomiphene citrate-stimulated cycles: Human chorionic gonadotropin versus a gonadotropin releasing hormone agonist

Purpose To compare the use of human chorionic gonadotropin (hCG) to a gonadotropin releasing hormone (GnRH) agonist, nafarelin, in initiating ovulation and supporting the luteal phase after priming with clomiphene.Methods In 26 infertile women 50 mg clomiphene citrate produced a preovulatory-size follicle. Then, 11 women were randomized to receive two 400-g doses of nafarelin intranasally 16 h apart, and 15 women were injected intramuscularly with 5000 IU of hCG (luteal day 0 = LD0). Starting on LD6, 7 more 400-g doses of nafarelin were repeated on an every 16-h schedule or a single 2500 IU dose of hCG was given, respectively. Serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂), progesterone (P), and hCG were measured. On LD13, endometrium was evaluated with ultrasonography and biopsy in 19 nonpregnant women.Results As judged by a threefold rise in serum LH, an LH surge was detected on LD1 in all 11 nafarelin patients, but in only 8 hCG patients (P = 0.01). LH and FSH levels were significantly higher on LD1, 7, and 8 and were significantly suppressed on LD13 in the nafarelin group. All patients had mid-luteal P levels greater than 10 ng/ml and luteal phases longer than 13 days. Significantly different luteal E₂ or P levels were noted only on LD13, with lower values in the nafarelin group. Pregnancies were achieved in 3 of 11 nafarelin cycles and 2 of 15 hCG cycles. Luteal phase defects were also similar: 4 of 8 nafarelin patients and 7 of 11 hCG patients.Conclusion Nafarelin or hCG in conjunction with clomiphene can result in viable pregnancies, but is associated with low pregnancy rates and a high incidence of luteal phase defects.     

小剂量补佳乐在诱导排卵中对子宫内膜发育的影响

目的探讨小剂量补佳乐是否能改善克罗米芬诱导排卵中的子宫内膜发育。方法45例不明原因或男方因素的不育妇女分为三组，自然周期组、克罗米芬组(CC组)、克罗米芬 补佳乐组(CC PGV组)各15例，观察三组hCG日及hCG 9d激素环境、子宫内膜厚度、子宫动脉搏动指数(PI)，hCG日子宫内膜类型。结果CC组无论hCG日还是hCG 9d内膜厚度均明显小于自然周期组，而CC PGV组内膜厚度均明显大于CC组。CC组和CC PGV组子宫动脉PI无显著差别，但均显著大于自然周期组。结论小剂量补佳乐能改善克罗米芬诱导排卵中子宫内膜的发育。