Some Fertility Medicines More Effective Than Others

Infertility with polycystic ovary syndrome may be better treated with letrozole

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Women with polycystic ovary syndrome can have a difficult time trying to become pregnant and often take medication to help with fertility. But some medicines may be more effective than others. 

A recent study found that the medication letrozole may be more successful in treating infertility than clomiphene for women with polycystic ovary syndrome.

"Discuss infertility treatment options with your OB-GYN."

This study was led by Richard Legro, MD, of the Department of Obstetrics and Gynecology at Penn State College of Medicine.

Polycystic ovary syndrome (PCOS) results from an imbalance of female sex hormones. It can cause ovarian cysts and problems with women's menstrual cycles. It can also cause infertility.

The researchers looked at whether the medication letrozole might be more effective than clomiphene for treating infertility in women with PCOS.

The authors of this study split 750 women into two groups — one to receive letrozole (brand name Femara) and one to receive clomiphene (commonly sold as Serophene or Clomid).

All the women received the medication for up to five fertility treatment cycles. During that time, they visited their clinicians to determine when they ovulated and whether they were pregnant.

All the women, aged 18 to 40, had at least one open and functioning fallopian tube and a normal uterus. They were all attempting to conceive with male partners who had a high enough sperm count (at least 14 million per milliliter) to cause pregnancy.

The researchers compared how many women in each medication group gave birth during the course of the study from 2009 to 2012.

Among the women who received letrozole, 28 percent gave birth, compared with 19 percent of the women who received clomiphene.

The researchers found no major differences in birth defects between the two groups of women.

The researchers also found a greater ovulation rate across cycles in the women who took letrozole instead of clomiphene.

The ovulation rate among the women taking clomiphene was 48 percent, but those taking letrozole had a rate of 62 percent.

Miscarriages were approximately equal in the two groups, occurring among nearly 32 percent of the women taking letrozole and 29 percent taking clomiphene.

Although twin pregnancies were slightly higher in the clomiphene group (7.4 percent) than the letrozole group (3.4 percent), this difference was not statistically significant, the researchers reported.

In terms of side effects, clomiphene users were more likely to experience hot flashes, while those taking letrozole were more likely to experience dizziness or fatigue.

The researchers concluded that letrozole led to a higher rate of pregnancies resulting in live births than clomiphene.

This study was published July 10 in The New England Journal of Medicine. The research was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development.

The study authors reported several potential conflicts of interest, which included consulting for and receiving grants from major pharmaceutical companies like AstraZeneca.

Review Date: 
July 17, 2014
Last Updated:
July 18, 2014