New research on Femara, not to be used for infertility
8 Replies
~ - February 2

I just went to my RE this week. He told me that he had gone to a convention in Nov. At the convention they informed all the docs that they have discovered Femara greatly increases chromosonal abnormalities/birth defects, so he is not prescribing it anymore.

Washington Post (Nov. 29, 2005)

The manufacturer of a breast cancer drug, letrozole (fermara), is warning fertility doctors that it has been associated with birth defects, a caution prompted by reports that the drug was being used to help a woman become pregnant.

Letrozole(femera) is approved for use ONLY in postmenopausal women with breast cancer. But there is evidence some doctors have prescribed it as a fertility treatment because it suppresses estrogen and can promote ovulation. It is marketed under the name Femara.

In its letter in Canada, Novartis (the drug company) said it is "aware that Femara is being used to stimulate ovulation in women who are infertile, or unable to become pregnant, as a treatment to increase their chances of becoming pregnant."

The drug "should not be used in women who may become pregnant, during pregnancy and/or while breast-feeding, because there is a potential risk of harm to the mother and the fetus, including risk of fetal malformations," the company said.

Pregnant women who have received the drug should contact their doctor.

The U.S. Food and Drug Administration has not taken any action, but a spokeswoman said the agency was reviewing the matter. Novartis plans to send a letter to U.S. fertility specialists by the end of the week , said Fox of Novartis.

More info:


Su - February 2

Wow, I didn't know that!!! Thanks for sharing. Baby dust!


jcr - February 3

read anyone on femara, K, goes into more detail about a questionable study!!!


K - February 3

I figured I should probably post this here also- especially since jcr already mentioned my research. Your RE apparently did not do any research into the validity of the Canadian study that was presented at the convention. There has been a scientific analysis of it that has found that this research study was likely flawed. The Canadian study was all over the press in December. Novartis is issuing warnings to all REs because of the study and the press coverage, but obviously that is to protect themselves from lawsuits. When I saw the reports on the Canadian study I was very concerned because I was already pregnant with a Femara baby, so I did some in depth research, and based on my research I don't have any concerns about Femara. My RE still prescribes it, and I plan on taking it again if I try for a second baby. Here's what I found: My research showed that most of the women who have reported birth defects turned out to have already been pregnant when taking the drug (the same thing can happen with Clomid). Also, I found a scientific analysis of the Canadian study that claims that Femara has a higher incidence of birth defects that complained that the Canadian study was likely skewed because a high proportion of the women taking the Femara of the 150 people they followed were older (already at a higher risk of birth defects), and it is also known that the incidence of birth defects is generally higher following infertility treatment, so because they only compared the percentage of defects with Femara to the percentage of defects with a group that had no fertility treatment whatsoever, you can't tell from the study whether the Femara would create any more risk of defect than any other fertility drug. That science group said that the Femara group should have been compared to groups undergoing other types of infertility treatment, not those who had no treatment . That scientific analysis also noted that the group of pregnant women studied that didn't take the drug (the control group) had an abormally low number of reported birth defects, so it might not be the best control group for comparison. According to the March of Dimes, 3-5% of babies in the United States are born with birth defects. The university of Iowa did a study which came out a few weeks ago that noted that 6.2 % of IVF babies have some sort of birth defect, 5% of IUI babies have some sort of birth defect and that the rate of birth defects in naturally conceived babies was 4.4%. In the Canadian study on Femara, the control group only had 1.8% with birth defects which is unusual, and the Femara group had about 4.7% which is not very far off of what would have been expected anyway, particularly as that group had a lot of older women. Plus the Femara group was not only made up of people who solely took Femara- some had taken other fertility drugs either before or with the Femara as well, which also could have skewed the results. The results of any research report can be misleading based on the data used behind the report. Based on my research, it's my opinion that the news reports were a whole lot of hoopla over a study that basically means nothing and appears to have been flawed, but everyone needs to decide for themselves. My husband is a biochemist who used to be a medical research scientist and he can't even believe they would do a study without better "controls" than the Canadian study. He agrees with the scientific analysis I found and he thinks the Canadian study was completely flawed and useless. Again, everyone needs to decide for themselves, but I wouldn't think twice about taking Femara again. After a 4 year battle with infertility, I am just a few weeks away from holding my little girl in my arms.


anonymous99 - February 27

if a med will cause defects, no matter older or younger, age does not make a difference. Femara and Clomid like any other fertility drug will cause harm when given to already pregnant women. There is no evidence that Femara causes defects in younger or older women.


Arch - December 2

Hi anonymous99,
I read your detailed description on Femara. I guess your baby is over a year old now. Please let us know that the baby is doing fine so that it helps people like who are very apprehensive about taking the femara


JND - December 2

Arch, I took femera and got pregnant my 1st cycle. My son is almost 16mths and he is as healthy as can be. Actually, come the new year I'm probably gonna have to take it again. Good luck. If people look hard enough there are gonna be side effects to ANYTHING. We just have to pray that all will be okay.


K - December 4

Hi guys. Saw this thread was live again. Just thought I would let you know that since my last post where I talked about what was wrong with the study, a new study came out in April 2007, that said that the old study was incorrect and that Femara was as safe as Clomid. My little girl is going to be 2 in a few months and she is a healthy happy kid. Thanks Femara. Articles on the new study can be found at www (dot) medpagetoday (dot) com/OBGYN/Infertility/tb/3144


K - December 4

If the above link doesn't work, you can go to medpagetoday and search femara. It will be on the list of articles it pulls up, the title is "Femara link to birth defects called incorrect". Right now it is about the 7th article down. There is also an article on news.softpedia. Again, just search "femara". That article is not as detailed as the first one.



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