Treating infertility: is letrozole more effective than clomiphene for patients with polycystic ovary syndrome?

This study investigated if letrozole (Femara) improves fertility outcomes in patients with polycystic ovary syndrome.

They found that letrozole was not superior to clomiphene (Clomid) in treating infertility in these women.

Polycystic ovary syndrome (PCOS) is a condition that can lead to infertility. It is caused by cysts on the ovaries. Ovarian cysts can lead to an overproduction of male hormones (androgens). It can also cause irregular or reduced periods (oligomenorrhea). Many women with PCOS experience fertility issues. Treating infertility in PCOS patients can be difficult. Clomiphene (CP) is a drug used to stimulate the release of eggs from the ovaries (ovulation). Some patients with PCOS do not respond to CP treatment.

Letrozole (LTZ) is a drug that blocks a type of enzymes called aromatases. Aromatases are involved in the production of the female hormone estrogen. LTZ blocks estrogen production and has been used to treat breast cancer. Blocking estrogen production also stimulates ovulation. As a result, LTZ may be useful to stimulate ovulation in patients that are resistant to CP. It is unclear if LTZ is more effective than CP in treating infertility in patients with PCOS.

This study included the medical records of 136 women with infertility and PCOS. Women received either LTZ or CP treatment to stimulate ovulation. The authors analyzed a number of fertility outcomes from medical records. These included birth rates, pregnancy rates, and ovulation.  

Patients treated with LTZ had higher birth rates (29.4%) compared to patients treated with CP (17.6%). Ovulation and conception rates were also higher in the LTZ group (86.8% and 39.7%) than in the CP group (75% and 25%). The rates of pregnancy and pregnancy loss were higher in the LTZ group (32.4% and 7.4%) compared to CP (20.6% and 4.4%). However, these results were not statistically significant.

The number of adverse events was similar in both groups. These included hot flushes, fatigue, and dizziness.

The authors concluded that letrozole was not superior to clomiphene in treating infertility.

The number of patients in this study was relatively small. The protocols for treatment varied among patients. A controlled trial is needed to confirm the findings in this study.

If you have any concerns regarding fertility treatment, please discuss this with your doctor.