Hi there,  I would like to ask about uterine lining between cd2-4 please.
I have very heavy periods which is normal for me. I have tried 3 cycles of iui and all were negative. I or my husband have no known fertilty problems and we have been told we have secondary unexplained infertility. I am 36 years old. At all my baseline scans my uterine lining is 10-12mm on cd2 and on cd4 it is about 4mm. I also seem to have 1 or 2 follicles at around 9-10mm on cd2. Is this normal? I Then start gonal f injections cd4 or cd5 at 66.2 units until cd 10 where I am ready to trigger with only 1 follicle. The aim was to stimulate 2-3 follicles but I believe that due to there being a follicle already at 9-10mm on cd2 and also the fact that my clinic starts me on injections quite late as opossed to others who start on cd2 or 3 that this could be the reason I only have 1 follicle? Or could it be that the 10mm follicle that is already present takes up all the medication and therefor no other follicles get a chance? In a similar situation to mine, what approach would you take with your patients?
Any advice will be much appreciated. I am from the uk.

Hello Zaara from the U.K.,

It is normal to have a thinned uterine lining and some baseline antral follicles at the beginning of the cycle.  9-10 is a little larger than usual but not unusual or abnormal.

You only have one follicle because you are not getting enough stimulation.  Starting on CD#4 is not necessarily too late and if enough FSH is given, additional follicles should grow.  The only impact having larger follicles is that you would reach the point of maturity faster.

My protocol is different, and you will find that there are differences among all the different fertility specialists.  There is no one correct protocol or gold standard.  I start stimulation on CD#2 and use a step up protocol with IUI.  That is, I start at a low dose, like 75IU and recheck the estradiol level every 3-4 days to see if there is stimulation at that dose.  I then increase or adjust the medication dosage as needed.  The first ultrasound is done on CD#9 to determine the status of the follicles (how many, what sizes).  Additional ultrasounds are then done as needed until the follicles reach 16-22 mms, at which point I trigger with Ovidrel.  IUI's are then done at 24 hrs and 48 hrs.

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.  I also now provide an Email Concierge Advisory Service with a 1 year subscription for patients that want easy access to me to answer questions along their journey (women's health, infertility, pregnancy).  Contact me at if you are interested in continuous access to me.


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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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