Background: Polycystic ovary syndrome (PCOS) is the most frequent cause of anovulatory infertility. The standard treatment for induction of ovulation is using clomiphene citrate (CC); however, approximately 20% of patients with PCOS are resistant to CC. An alternative is the aromatase inhibitor letrozole. Objective: This article summarizes the current state of knowledge on induction of ovulation with CC and letrozole. The results of relevant studies are described and discusssed. Results: In comparison to CC, letrozole has no negative antiestrogen effects. Any doubts with respect to teratogenic risks in comparison to CC have so far not been confirmed and the much shorter half-life of 48 h is also positive in this respect. Under letrozole treatment ovulation rates of 70-84% and pregnancy rates of 20-27% per cycle have been described in women with PCOS and CC resistance. This is where the therapeutic approach seems to be particularly advantageous. Comparisons with CC showed higher ovulation, pregnancy and live birth rates after induction of ovulation with letrozole. Patients with a high body mass index (BMI) also have a particular benefit from letrozole. Conclusion: Letrozole is a safe drug for induction of ovulation. Letrozole appears to have particular advantages in PCOS and CC resistance as well as in PCOS and obesity but particular caution should be exercised with off-label use.
|Translated title of the contribution||Letrozole for ovulation induction in polycystic ovary syndrome|
|Number of pages||4|
|Publication status||Published - 01.09.2017|