Evaluating letrozole versus menotropin for patients with PCOS

This study compared two methods to induce ovulation (egg release) in women with polycystic ovarian syndrome (PCOS). This study found that letrozole (Femara) and menotropin (Humegon) resulted in similar pregnancy rates, but letrozole had fewer side effects.

PCOS is a common cause of infertility in women. In PCOS, follicles (structures in the ovaries that contain eggs) may develop, but egg release is delayed or does not happen. Clomiphene citrate (Clomid; CC) is the usual first-line treatment for PCOS. However, some women do not respond to CC. It is also associated with side effects that can interfere with pregnancy, such as drying up cervical fluid and thinning the lining of the womb.

There are a few options for women who do not respond to CC. Menotropin (human menopausal gonadotropin) is a hormone that stimulates the ovary follicles. Menotropin can cause multiple pregnancies (twins or triplets), which are more likely to have complications. Letrozole is another option; it helps the body produce hormones. Which of these treatments is more effective for treating PCOS is unclear.

This study had 96 women with PCOS that did not respond to CC. Half of the patients received letrozole, and the other half received menotropin for one menstrual cycle. Follicle development was monitored during treatment. When one or more follicles matured, ovulation was induced, and patients were directed to have sex within 24 hours.

The number of cycles that led to egg release was similar between letrozole and menotropin (53.6% vs. 64.7%). Menotropin had significantly more cycles with at least 2 mature follicles compared to letrozole (25.2% vs. 10.4%). However, cysts and overstimulation of the ovaries were significantly less common with letrozole compared to menotropin.

Overall, similar numbers of patients became pregnant in each group (22.9%, letrozole vs. 21.7%, menotropin).  Multiple pregnancies were significantly more common in the menotropin group (8.3% vs. 4.2%). Both groups had a live birth rate of 16.7%.

This study found that letrozole and menotropin were both effective at inducing ovulation and pregnancy for women with PCOS. However, letrozole was associated with fewer side effects.

This study had a small number of patients. Larger studies are needed to confirm these results.

If you are using medication to treat PCOS, talk to your doctor about whether letrozole may be right for you.