Exogenous estrogen therapy concurrent with clomiphene citrate--lack of effect on serum sex hormone levels and endometrial thickness

Ultra-short term clomiphene citrate in high responder women with polycystic ovary syndrome: a case series

OBJECTIVE

To evaluate a new trial of short-term clomiphene citrate (CC) in high responder women with polycystic ovary syndrome (PCOS).

STUDY DESIGN

This case series was conducted in the infertility outpatient clinics of two centres. Ovulation induction was performed with CC 50-100mg a day in six high-responder women with PCOS who had a history of cancellation of treatment because of ≥3 mature follicles between March 2010 and June 2013. Induction was initiated on the third day of their cycles and the duration of induction was only two days. Demographic data of the patients, number of mature follicles on hCG day, ovulation rate, luteal phase length, pregnancy rate, and type of pregnancy were recorded. All data were analysed by SPSS packet programme (SPSS, 17.0, SPSS Inc., Chicago, IL, USA).

RESULT(S)

The median number of mature follicles and duration of the follicular phase were 1.3 (1-2) and 11.9 (11-14) days, respectively. The ovulation rate was 80% (12/15) and pregnancy rate per cycle was 26.6%.

CONCLUSION(S)

If this hypothesis is supported by large prospective randomised controlled studies, ultra-short term ovulation induction with CC may provide an alternative approach for high-responder women with PCOS who have a history of treatment cycle cancellations.

Use of the aromatase inhibitor letrozole for ovulation induction in women with polycystic ovarian syndrome

Clomiphene citrate (CC) is the most commonly used oral agent for the induction of ovulation. It is a nonsteroidal selective estrogen receptor modulator that has predominant antiestrogenic action resulting in long-lasting estrogen receptor depletion. Side effects include antiestrogenic effects systemically and on the endometrium and cervical mucous. Letrozole is a potent, nonsteroidal, aromatase inhibitor, originally used for postmenopausal breast cancer therapy, at present its only registered indication. We hypothesized that letrozole could mimic the action of CC without depletion of estrogen receptors. As there is no estrogen receptor antagonism, antiestrogenic effects such as poor cervical mucus and thin endometrium are not expected with aromatase inhibitor treatment. In addition, because estrogen receptors in the brain are not depleted, normal negative feedback occurs with letrozole and generally results in monoovulation. We and others have demonstrated the success of aromatase inhibition in inducing ovulation in women with polycystic ovarian syndrome. Letrozole may be very effective for ovulation induction and pregnancy in cases of CC resistance. When used together with follicle-stimulating hormone (FSH) injections, letrozole resulted in a significant reduction in the FSH dose needed for controlled ovarian hyperstimulation. Aromatase inhibitors likely increase ovarian sensitivity to FSH, and may be useful in poor responders and in women undergoing ovarian stimulation for in vitro fertilization. The safety of letrozole in pregnancy outcome studies has been demonstrated by examination of spontaneous pregnancy loss, multiple pregnancy rates, and congenital anomalies compared with a control group of infertility patients treated with CC. In addition, new data suggest that CC may result in cardiac anomalies and other birth defects and in low birth weight babies. We believe aromatase inhibitors are acceptable alternatives to CC as first line oral agents for ovulation induction or controlled ovarian stimulation.

Randomized controlled trial comparing superovulation with letrozole versus recombinant follicle-stimulating hormone combined with intrauterine insemination for couples with unexplained infertility who had failed clomiphene citrate stimulation and intrauterine insemination

OBJECTIVE

To compare the efficacy of letrozole to recombinant FSH for ovarian stimulation combined with IUI in a group of patients that had failed to conceive after clomiphene citrate (CC) and IUI.

DESIGN

Prospective randomized trial with human subjects.

SETTING

University-based fertility center.

PATIENT(S)

Fifty couples with unexplained infertility that failed to conceive after three cycles of CC combined to IUI.

INTERVENTION(S)

Couples were randomized to undergo superovulation either with letrozole or with recombinant FSH combined to IUI.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy per cycle of treatment and clinical pregnancy per couple.

RESULT(S)

Pregnancy rate (PR) per cycle was 8.9% in the letrozole group as compared with 14% in the gonadotropin IUI group. This resulted in a cumulative PR per couple of 24% versus 36% and a take home baby rate of 20% versus 28%. Endometrial thickness was significantly lower in the letrozole group (7.1 +/- 2.3 vs 8.6 +/- 1.8).

CONCLUSION(S)

Ovarian stimulation with letrozole is associated with acceptable PRs compared with gonadotropin with significant less cost, risks, and patient inconvenience.

Review: aromatase inhibitors for ovulation induction

CONTEXT

For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC). CC is a safe, effective oral agent but is known to have relatively common antiestrogenic endometrial and cervical mucous side effects that could prevent pregnancy in the face of successful ovulation. In addition, there is a significant risk of multiple pregnancy with CC, compared with natural cycles. Because of these problems, we proposed the concept of aromatase inhibition as a new method of ovulation induction that could avoid many of the adverse effects of CC. The objective of this review was to describe the different physiological mechanisms of action for CC and aromatase inhibitors (AIs) and compare studies of efficacy for both agents for ovulation induction.

EVIDENCE ACQUISITION

We conducted a systematic review of all the published studies, both controlled and noncontrolled, comparing CC and AI treatment, either alone or in combination with gonadotropins, for ovulation induction or augmentation, identified through the Entrez-PubMed search engine.

EVIDENCE SYNTHESIS

Because of the recent acceptance of the concept of using AIs for ovulation induction, few controlled studies were identified, and the rest of the studies were pilot or preliminary comparisons. Based on these studies, it appears that AIs are as effective as CC in inducing ovulation, are devoid of any antiestrogenic side effects, result in lower serum estrogen concentrations, and are associated with good pregnancy rates with a lower incidence of multiple pregnancy than CC. When combined with gonadotropins for assisted reproductive technologies, AIs reduce the dose of FSH required for optimal follicle recruitment and improve the response to FSH in poor responders.

CONCLUSIONS

Preliminary evidence suggests that AIs may replace CC in the future because of similar efficacy with a reduced side effect profile. Although worldwide experience with AIs for ovulation induction is increasing, at present, definitive studies in the form of randomized controlled trials comparing CC with AIs are lacking.

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality.

Estradiol protects clomiphene citrate–induced apoptosis in ovarian follicular cells and ovulated cumulus–oocyte complexes

OBJECTIVE

To determine whether clomiphene citrate (CC) reduces E(2) level in the ovary and circulation and induces apoptosis in ovarian follicular cells and ovulated cumulus-oocyte complexes (COCs). If yes, to determine whether E(2) coadministration could protect against these adverse effects of CC.

DESIGN

A controlled prospective study.

SETTING

Laboratory research setting.

ANIMAL(S)

Ninety sexually immature female rats that were 24-25 days of age.

INTERVENTION(S)

The immature female rats were injected with a single dose of 10 IU of pregnant mare serum gonadotropin. After 48 hours, 10 IU of hCG along with 10 mg of CC per kilogram of body weight, with or without 2.0 mg of E2 per kilogram of body weight were coadministered. After 16 hrs, the rats were killed; COCs were collected from oviduct and ovaries were isolated.

MAIN OUTCOME MEASURE(S)

Number of superovulated COCs, oocyte morphology, E2 level in ovary and serum, histology of ovary, DNA fragmentation, and bax protein expression in ovary and COCs.

RESULT(S)

The number of COCs and E2 level in ovary and serum were reduced, whereas membrane blebbing in oocytes, bax protein expression, and DNA fragmentation in ovarian follicular cells and ovulated COCs were induced after CC treatment. These adverse effects of CC were protected against if animals were coadministered with E2.

CONCLUSION(S)

Clomiphene citrate-induced apoptosis in ovarian follicular cells (probably granulosa cells), thereby reducing E2 level in ovary and circulation that might have resulted in poor development and maturation of oocytes leading to reduced ovulation.

Is ovulation induction still a therapeutic problem in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases affecting women of fertile age, and is characterized by hyperandrogenism, chronic anovulatory cycles and oligomenorrhea or amenorrhea. Given the repercussions of chronic anovulation on sterility, PCOS is a heavy social burden. Here we describe the procedures used to induce ovulation in PCOS patients, the surgical approach and medical treatments that are still being experimented.

Aromatase inhibitors for the treatment of infertility

Ovarian stimulation during infertility treatment is used either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antioestrogen, clomiphene citrate and injectable gonadotrophins. In spite of the high ovulation rate, the use of clomiphene citrate is associated with adverse side effects and low pregnancy rates. In clomiphene citrate failures, gonadotrophin injections are generally the next treatment option but, especially in polycystic ovarian syndrome, are associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of ovarian hyperstimulation syndrome and with minimal monitoring is preferred. It was hypothesised that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus and/or pituitary from oestrogen negative feedback. The success of aromatase inhibitors in induction and augmentation of ovulation has been reported. In addition, increased intraovarian androgen levels may synergise with central effects of decreased oestrogen to enhance ovarian response to gonadotrophin stimulation. This increased sensitivity to follicle-stimulating hormone may be especially useful in poor responders. The potential future applications for aromatase inhibitors in infertility management are also discussed.

Aromatase inhibition for ovarian stimulation: future avenues for infertility management

Ovarian stimulation is applied during infertility management either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antiestrogen, clomiphene citrate, and injectable gonadotropins. In spite of the high ovulation rate with the use of clomiphene citrate, the pregnancy rate is much lower. In clomiphene citrate failures, gonadotropin injections have generally been used as the next treatment option. Treatment with gonadotropins is difficult to control and characteristically associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of hyperstimulation and with minimal monitoring is the preferred therapy. We hypothesize that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus or pituitary from estrogen negative feedback. Based on this hypothesis, we have reported the success of aromatase inhibitors in induction and augmentation of ovulation in addition to improving ovarian response to gonadotropin stimulation. Moreover, there are other potential applications for aromatase inhibitors in infertility management, including improving implantation in assisted reproduction and in-vitro maturation.

Alcoholic hypogonadism: hormonal response to clomiphene

To investigate the androgen, weak androgen, estrogen, and gonadotrophin response to clomiphene in alcoholics, we determined in 63 male patients (25 with and 38 without liver cirrhosis) serum testosterone, sexual hormone binding protein (SHBG), dehidroepiandrosterone, androstenedione, LH, FSH, prolactin, and estradiol levels, on the first and the sixth day after admission, and after a course of 8 days of clomiphene 200 mg/day. The same test was performed on 15 healthy volunteers. Cirrhotic patients showed decreased basal testosterone levels and a loss of the circadian rhythm with recovery after clomiphene. Although basal testosterone levels in noncirrhotic alcoholics did not differ from those of the controls, there was a significant improvement after withdrawal. SHBG levels were higher in both groups of alcoholics than in controls, pointing to a worse degree of hypogonadism, because only the free hormone is active. Before the clomiphene test, serum LH and FSH levels were nonsignificantly higher in both groups of alcoholics than in the control group. After clomiphene both LH and FSH increased. Androstenedione and estradiol showed a (parallelism) similar behavior in alcoholic and in cirrhotic groups, showing in both cases higher levels than in the control group, and an increase after clomiphene, perhaps reflecting peripheral conversion of androgens to estrogens. Because clomiphene has no effect on the adrenal cortex, the increase of androstenedione after clomiphene points to its testicular origin (directly or after testosterone conversion) and not to an adrenal one. The highest serum estradiol levels were observed in cirrhotics with ascites or gynecomastia. We have not found any relation between serum hormone levels and alcohol intake nor with nutritional status.