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Infertility/Fertility/Clomid & Estrogen vaginal tablets


Dear Dr. Ramirez,

My wife and I have been trying to conceive our second child unsuccessfully for the past 3 months now. She is 32 while I am 33.  We are both of Asian descent.  She has been to an infertility specialist here in Taipei, Taiwan who prescribed Clomid (50 mg). He also explained to her some of the possible side effects such as the thinning of the uterus lining.    

I also noticed you touched on this in a recent response where you said, "a side effect of the medication is that it can block the estrogen receptors in the endometrium and lead to a thinned endometrium.  For that reason, I do not use Clomid in consecutive months because it adds up.

"One thing you can do is add estrogen vaginal tablets such as estrace tabs used vaginally, or any other estrogen tablet, but used vaginally, or you can use a vaginal gel or an estrogen patch...The other thing you can do is alternate Clomid with another ovulation medications called Letrozole (Femara), which doesn't have the endometrial thinning side effects that Clomid has."

Since my wife has been taking Clomid for 3 consecutive months now, we are facing the same problem. My question is, which option (estrogen tabs or Letrozole) is has fewer side effects?  Which option is more effective in conceiving?

Thank you for volunteering Dr. Ramirez.

Taipei, Taiwan

Hello Michael from Taiwan,

Either estrogen tabs or Letrozole or both can be used.  The Letrozole is used instead of the Clomid so that you can continue trying in consecutive cycles.  The estrogen tabs have the least side effect, because it is natural estrogen, but does nothing to help with ovulation induction.  For that, you would need either Clomid or Letrozole.  Since you have used Clomid for three consecutive cycles now, I would recommend either skipping one cycle or using the Letrozole if you want to continue the cycles.

Just a side note, if you have only been trying on your own naturally for three months, you've hardly given yourselves a chance to get pregnant naturally.  It takes 8-12 months, on average, for a woman under the age of 30 to get pregnant.  It can take a little longer for women over 30.  I think your doctor has jumped to Clomid prematurely.  It is not a magic drug and shouldn't be used inappropriately.   Since your wife is young, I would recommend that you go back to trying on your own for another 9 months and then if it is not successful, it would be time to do an infertility evaluation before moving to any treatment.  What is your doctor treating?

Good Luck,

Dr. Edward J. Ramirez, M.D., FACOG
Executive Medical Director
The Fertility and Gynecology Center
Monterey Bay IVF Program

Monterey, California, U.S.A.

for additional information check out my blog at check me out on twitter with me at @montereybayivf and facebook @montereybayivf.  Skype and internet comprehensive consultations now available via my website for those who want a more extensive evaluation that this site can accommodate


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Edward Joseph Ramirez, MD, FACOG


I am a specialist in infertility and advanced gynecological care. I can answer questions about infertility, gynecology related ills, menopause...virtually anything that affects women's health. PLEASE tell me where you are writing from as I am always interested.


I have been practicing as an Ob/Gyn and Infertility Specialist for over 23 years. Gynecology, advanced laparoscopic surgery, basic infertility, IUI's, IVF, reproductive surgery, and ovulation induction are all areas of my expertise. I am Board Certified. I have been doing In Vitro Fertilization in my clinic for 19 years.

American College of OB/GYN, American Board of Obstetrics and Gynecology, American Society of Reproductive Medicine, California Medical Association, American Association of Gynecologic Laparoscopists, Fellow of The American College of Obstetricians & Gynecologists

American Journal of Obstetrics and Gynecology, Wall Street Journal, Monterey Herald, SERMO, Women's Health and Fertility Blog

Medical Degree from Stanford University, Residency at Tripler Army Medical Center, Reproductive Training at Pacific Fertility Center, San Francisco

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