A Closer Look at Letrozole

In this study, 14 of 514 newborns (2.4%) in the letrozole group and 19 of 397 newborns (4.8%) in the clomiphene group were found to have any congenital anomaly. For major malformations, the rates were 6/514 (1.2%) for letrozole and 12/397 (3.0%) in the clomiphene group. These rates were not statistically significantly different, and were felt by the authors to be similar to rates of congenital anomalies seen in the general population. In the field of medicine, there are hundreds of medications that were originally discovered to treat one condition and are subsequently found to be useful for other conditions. Once a drug is approved for a specific indication, most pharmaceutical companies will not go through the trouble and expense to have their drug officially approved for another indication. We at Pacific Fertility have carefully reviewed the data and circumstances around the controversy and we continue to believe that the use of letrozole is appropriate in certain circumstances and with full disclosure. Hundreds of infertility centers and OBGYN clinics worldwide are doing the same. Although no broad scientific studies have yet established the efficacy of letrozole as the first course standard treatment for treating ovulatory problems, preliminary studies have shown letrozole to be useful, especially for women whose uterine lining may be thinned out by clomiphene (Clomid). Please see the [Science Pulse Extra](http://www.infertilitydoctor.com/2006/05/03/science-pulse-extra-how-letrozole-works/) to learn more about how letrozole works. The only other alternative to clomiphene for ovulation induction is the use of injectable fertility medications (gonadotropins). Use of these drugs in anovulatory women can be tricky, as it is often difficult to induce just one or two eggs to mature with these powerful drugs. So the risks of ovarian hyperstimulation and multiple gestation are significantly higher in anovulatory women on gonadotropins. We at Pacific Fertility Center carefully explain to those women who might benefit from its treatment the controversy as well as the potential for adverse reactions. Letrozole is generally prescribed to be taken from days 3-7 of the menstrual cycle and has a short life span in the body. There are no traces of the medication in the body by the time an embryo will be implanting. -- Carolyn Givens, MD

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