Aromatase inhibitors for ovulation and pregnancy in polycystic ovary syndrome.
OBJECTIVE
To evaluate evidence for use of aromatase inhibitors for ovulation induction and pregnancy in patients with polycystic ovary syndrome (PCOS).


METHODS
A MEDLINE search (1966-May 2009) was conducted using the search terms anastrozole, aromatase inhibitors, exemestane, letrozole, ovulation, and polycystic ovary syndrome to identify relevant studies.


METHODS
Prospective clinical trials published in English and conducted in humans were identified. Trials using intrauterine insemination methods for pregnancy were excluded. The resulting articles were separated into 2 groups: aromatase inhibitor use in clomiphene-resistant patients and use in treatment-naïve patients. Eleven trials were reviewed.


RESULTS
Accepted pharmacologic treatments for women with PCOS and infertility include clomiphene citrate, gonadotropins, and gonadotropin-releasing hormone (GnRH) analogs. Each medication has variable efficacy rates and adverse effects. Therefore, other treatments are needed for a subset of women with PCOS and infertility. Evidence suggests that nonsteroidal aromatase inhibitors, specifically letrozole and anastrozole, may have ovulation-inducing effects by inhibiting androgen-to-estrogen conversion. Select trials with aromatase inhibitors have demonstrated efficacy for increased endometrium thickness, ovulation rates, and pregnancy rates when used in clomiphene citrate-resistant or treatment-naïve patients.


CONCLUSIONS
Further trials comparing aromatase inhibitors with clomiphene citrate are necessary before aromatase inhibitors can be recommended routinely for ovulation induction in women with PCOS and infertility. However, aromatase inhibitors may be considered in a subset of this population, specifically women who are clomiphene citrate resistant or those who, after discussion of risks and benefits, are not candidates for clomiphene citrate, gonadotropins, or GnRH analogs.
Eckmann
Karen R
KR
Virginia Commonwealth University Health System/Medical College of Virginia Hospitals, Richmond, VA, USA.
Kockler
Denise R
DR
D047072:Aromatase Inhibitors / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D002996:Clomiphene / Q000627:therapeutic use; D005260:Female; D005300:Fertility Agents, Female / Q000627:therapeutic use; D006801:Humans; D007247:Infertility, Female / Q000188:drug therapy / Q000209:etiology; D010062:Ovulation Induction / Q000379:methods*; D011085:Polycystic Ovary Syndrome / Q000150:complications*; D011247:Pregnancy
D047072:Aromatase Inhibitors; D005300:Fertility Agents, Female; D002996:Clomiphene