Aromatase inhibitors have been proposed as an alternative treatment to clomiphene. Aromatase inhibitors were originally used in the treatment of breast cancer and prostate cancer, but now have proven effective at increasing the chances of getting pregnant. Recent findings in a multicentre, randomized controlled trial comparing letrozole with clomiphene in 750 pcos patients having regular intercourse, live birth rates were. Others, as well as ourselves, have reported the success of letrozole, one of the thirdgeneration aromatase inhibitors, in inducing and augmenting ovulation, in addition to other benefits associated with reducing the. Ais exert an ovulation inducing effect by inhibiting the aromatase, and ubiquitous but mostly found in the granulosa cells, fat tissue, and placenta cytochrome p450 enzyme complex.
Use of aromatase inhibitors to induce ovulation has, therefore, been advocated because of their ease of administration, low cost and potential superiority over cc. Aromatase inhibitors are a class of drugs that block estrogen biosynthesis, thereby reducing negative estrogenic feedback at the pituitary. Aromatase inhibitors ais were introduced 15 years ago as possible oral agents for ovulation induction in polycystic ovary syndrome pcos. Ovarian stimulation with the aromatase inhibitor letrozole has been proposed for ovulation induction in order to treat unexplained female infertility. Jun 21, 2011 aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with pcos. Clomiphene isassociatedwithahighovulation 6080%butrelatively poor pregnancy rate 3040%.
Ovulation induction in women with polycystic ovary syndrome. Pregnancy outcome after ovulation induction with aromatase. Ovulation induction is a treatment for anovulation, an infertility condition in which follicles in a womans ovary do not mature and release eggs. Letrozole is one of the thirdgeneration aromatase inhibitors used more extensively than others for the treatment of infertility. Aromatase inhibitors for female infertility reproductive biomedicine. Drs mitwally and casper have patent applications for use of aromatase inhibitors for ovulation induction and a licensing agreement with serono for commercialisation of aromatase inhibitors for ovulation induction. We believe aromatase inhibitors are acceptable alternatives to cc as first line oral agents for ovulation induction or controlled ovarian stimulation. Recent research has focused on the successful use of aromatase inhibitors, mainly letrozole, for ovulation induction. A historical perspective of aromatase inhibitors for. Aromatase inhibitors, infertility, ovulation induction, birth defects, multiple pregnancy, polycystic ovary syndrome pcos. Polycystic ovary syndrome occurs in 4%8% of women worldwide and usually leads to anovulatory subfertility. The use of aromatase inhibitors for ovulation induction. Aromatase inhibitors were introduced in 2001 for induction of ovulation.
A historical perspective of aromatase inhibitors for ovulation induction. Ais exert an ovulationinducing effect by inhibiting the aromatase, and ubiquitous but mostly found in the granulosa cells, fat tissue, and placenta cytochrome p450 enzyme complex. Citrate cc therapy as the discrepancy between ovulation. Aromatase inhibitors ais were introduced 15 years ago as possible oral agents for ovulation induction in polycystic ovary syndrome pcos patients. The new third generation aromatase inhibitors are extremely potent and specific oral inhibitors of estrogen production. Aromatase inhibitors for subfertile women with polycystic. They are effective in inducing ovulation on the basis of the published reports. It has been used offlabel for ovulation induction as part of the ivf process since 2001. It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. If you continue browsing the site, you agree to the use of cookies on this website. Aromatase inhibitors such as testolactone have been approved for the treatment of gynecomastia in children and adolescents. After 4 decades of cc treatment, a new era of ovulation induction has. The medications were prescribed using an escalating dose if ovulation did not occur.
Recent studies have found that aromatase inhibitors may be safe and useful agents for ovulation induction in patients with polycystic ovarian syndrome as well a treatment option for superovulation in patients with either unexplained infertility or endometriosis. Letrozole is one of the thirdgeneration aromatase inhibitors used more extensively than. In a metaanalysis summarizing clinical trials testing aromatase inhibitors used alone or with other medical therapies for ovulation induction in pcos patients, live birth rates were again significantly higher when letrozole was compared with clomiphene citrate odds ratio or 1. Letrozole, a thirdgeneration aromatase inhibitor, is the most commonly used for ovulation induction protocols 6,7 and has been integrated into clinical practice to varying degrees. Letrozole is an oral nonsteroidal aromatase inhibitor approved for the treatment of hormonally responsive breast cancer after surgery. Clearly, an inexpensive yet equally efficacious oral alternative would be ideal. Daya hamilton, ontario, canada infertility is a fairly prevalent disorder that affects one in seven couples in the reproductive age. The use of aromatase inhibitors for ovulation induction and. Aromatase inhibitors for ovulation induction the journal of clinical. Ovulation induction in women with polycystic ovary. Aromatase inhibitors are approved solely for the pallia tive or adjuvant treatment of postmenopausal women with estrogenreceptorpositive breast cancer. Aromatase inhibitors are promising new drugs for the induction of ovulation and superovulation. Letrozole is an attractive option with its oral route of administration, cost, safety profile and effectiveness in ovulation induction and ovarian.
Aromatase inhibitors for ovulation induction request pdf. Approximately 15% of the infertile population faces an ovulatory disorder. In addition, new data suggest that cc may result in cardiac anomalies and other birth defects and in low birth weight babies. The two main indications for cc treatment are induction of ovulation in anovulatory infertility and stimulating multifollicular ovulation or enhancing ovulation in ovulatory infertile women, e. Aromatase inhibitors for ovulation induction the journal of.
Approximately 25 percent of female infertility cases stem from problems with ovulation, so ovulation induction can be a beneficial and costeffective first treatment. Letrozole belongs to a class of drugs called aromatase inhibitors. Aromatase inhibitors may be an effective alternative treatment to clomiphene citrate for both ovulation induction and superovulation. Use of the aromatase inhibitor letrozole for ovulation induction in women with polycystic ovarian syndrome. The medical team at georgia reproductive specialists has begun incorporating letrozole into treatment plans for appropriately selected patients. To evaluate evidence for use of aromatase inhibitors for ovulation induction and pregnancy in patients with polycystic ovary syndrome pcos. Aromatase inhibitors for ovulation induction and ovarian. Aromatase inhibitors in stimulated ivf cycles reproductive. Because of these problems, the concept of aromatase inhibition was proposed as a new method of ovulation induction that could avoid many of. Letrozole versus clomiphene for ovulation induction.
The ai, letrozole, is effective in ovulation induction in women with pcos resistant to clomifene citrate and ovarian stimulation for intrauterine insemination and in vitro fertilization ivf. Since 2005, there have been well over 100 publications describing the use of aromatase inhibitors, predominantly letrozole, in assisted reproduction, including ovulation induction in pcos, combined with gonadotropins in controlled ovarian stimulation for intrauterine insemination or in vitro fertilization, or in women with breast cancer. Ovulation induction remains a milestone in the treatment of women with anovulatory infertility. Jun 19, 2014 clearly, an inexpensive yet equally efficacious oral alternative would be ideal. Its worldwide usage for ovulation induction, including as an adjunct for intrauterine insemination and in vitro fertilization has occurred despite the absence of definitive data of superiority to cc. Others, as well as ourselves, have reported the success of letrozole, one of the thirdgeneration aromatase inhibitors, in inducing and augmenting ovulation, in addition to. Although several randomized trials have been conducted regarding their use as ovulation induction agents, only few trials are available regarding their efficacy in ivf stimulated cycles. Aromatase inhibitor shows promise in fertility treatment. Ais are divided into two categories, steroidal aromatase inhibitors sais, type 1 inhibitors and nonsteroidal aromatase inhibitors type 2 inhibitors that is based on their mechanism of action and structure. Aromatase inhibitors have been introduced as a new treatment modality that could challenge clomiphene citrate as an ovulation induction regiment in patients with pcos. Given the advantages of aromatase inhibitors, they can be used to replace cc as ovulationinducing drugs.
Because of these problems, we proposed aromatase inhibition as a new method of ovulation induction. Ovulation occurred in nine patients 75% and pregnancy occurred in three 25% 1. Aromatase inhibitor an overview sciencedirect topics. Aromatase inhibitors for ovulation and pregnancy in. During the past decade, aromatase inhibitors have been explored as an option for ovulation induction in women who fail to conceive with clomiphene citrate. Sep 12, 2012 supported in part by grants from the canadian institutes of health research, ottawa, ontario, canada. Advantages of aromatase inhibitors in ovulation induction relatively short halflife 45 hrs it t t lf db k h iintact central feedback mechanisms increase follicular sensitivity to fsh no adverse effects on endometrium or cervical mucouscervical mucous safe for community gynaecologists. We reported the success of using aromatase inhibitors for induction of ovulation in world health organization who type ii anovulatory patients.
The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment. The prime and only licensed use of letrozole is as an additional adjuvant treatment of breast cancer in postmenopausal women. Supported in part by grants from the canadian institutes of health research, ottawa, ontario, canada. Co the use of aromatase inhibitors for ovulation induction. Presented in part at the 56th annual meeting of the american society for reproductive medicine, san diego, california, october 2126, 2000. Unlike cc, they do not carry an antiestrogenic effect on the endometrium. Potential of aromatase inhibitors for ovulation and.
Aromatase inhibitors, a new option for inducing ovulation. Aromatase inhibitors for ovulation induction the journal. Ais exert an ovulationinducing effect by inhibiting the aromatase, and. Their use does not seem to be associated with adverse endometrial.
Use of an aromatase inhibitor for induction of ovulation in patients with an inadequate response to clomiphene citrate. A void aromatase inhibitors in these situations page 58 why aromatase inhibitors are superior to clomiphene page 60 five pearls for inducing ovulation page 73 the use of aromatase inhibitors for induction of ovulation represents an offlabel indication. Use of an aromatase inhibitor for induction of ovulation in. Use of an aromatase inhibitor for induction of ovulation. Ovulation induction is a treatment for anovulation irregular ovulation, an infertility condition in which follicles in a womans ovary do not mature and release eggs ovulate. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Aromatase inhibitors ais are a novel class of drugs that were introduced for ovulation induction in 2001. Thereafter, many studies discussed the efficacy of aromatase inhibitors in inducing ovulation in different clinical situations 2 6.
Pdf aromatase inhibitors for ovulation induction mohamed. Pdf aromatase inhibitors for ovulation induction researchgate. In a metaanalysis summarizing clinical trials testing aromatase inhibitors used alone or with other medical therapies for ovulation induction in pcos patients, live. Letrozole is an attractive option with its oral route of administration, cost, safety profile and effectiveness in ovulation induction and ovarian stimulation. The use of aromatase inhibitors in infertility and gynecology. Nsais are mainly used to treat breast cancer in women. Use of the aromatase inhibitor letrozole for ovulation. Letrozole for ovulation induction british fertility society. A void aromatase inhibitors in these situations page 58 why aromatase inhibitors are superior to clomiphene page 60 five pearls for inducing ovulation page 73 the use of aromatase inhibitors for. For these reasons, aromatase inhibitors can be used for ovulation induction in pcos.
Cc leads to long lasting estrogen receptor depletion. We believed it was time to develop a more effective ovulation induction agent, and we have demonstrated that aromatase inhibitors ais seem to be a promising alternative to cc for ovulation induction. Aromatase inhibitors for ovulation induction oxford academic. Aromatase inhibitors are the newest type of fertility drugs used in the infertility treatment of both men and women. Aromatase inhibitors are as effective as or superior to cc in ovulation induction and in superovulation. Recently, the safety of letrozole for ovulation induction have been seriously questioned. The concept of using aromatase inhibitors in place of clomiphene citrate cc for ovulation induction was introduced 10 years ago.
It is, however, being increasingly used as a treatment by fertility specialists to aid the development of ovarian follicles. Extended letrozole therapy for ovulation induction in. Normogonadotropic anovulation, including polycystic ovary syndrome pcos, is one of the main causes of infertility. Letrozole is more effective than clomiphene for ovulation induction in women with pcos and bmi 30. Ovulation induction ovulation induction at a glance. Letrozole is an attractive option with its oral route of administration, cost, safety profile and. Thereafter, many studies discussed the efficacy of aromatase inhibitors in inducing ovulation in different clinical situations 26. During the past decade, aromatase inhibitors have been explored as an option for ovulation induction in women who fail to conceive with. Nonsteroidal aromatase inhibitors nsais are one of two categories of aromatase inhibitors ais. Many studies have recently shown that using letrozole for ovulation induction results in better rates of successful ovulation and has no adverse. Letrozole versus clomiphene for ovulation induction mdedge. The safety of letrozole for ovulation induction have been seriously questioned. For anovulatory infertility, cc treatment will likely be effective only in conditions in which adequate levels of circulating estrogen exist to exert estrogennegative feedback on gonadotropin production, which in turn could be antagonized by the antiestrogenic effect of cc. Clomiphene citrate cc, the oral antiestrogen has long been used as the first line drug for induction of ovulation.