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21 Sep 2006

Normal Follicle Size
I am on CD12 and have just returned from a transviginal scan. I have one dominant follicle in my right ovary measuring 21mm. I am not on any fertility medication. The other follicles measured less than 5mm. In my left ovary I have a lot more follicles, none of which measure greater than 5mm.

I have a 28 day cycle. Is a dominant follicle of 21mm normal or too little. I am expecting to ovulate on CD13/14. Also, what does the size of one's follicle mean. Does a larger follicle mean that a better quality egg is released?

I would appreciate hearing from you.

Kind regards
Answer 227,509 views
Fertility expert
fertility expert

01 Jan 0001

Dear Imina

The presumption here is that you are being monitored on a natural cycle. The follicle size is appropriate for the stage of your cycle and ovulation should occur quite likely on day 13 or 14. The follicles usually start at 5-6mm and progressively increase until about 20-21mm before the egg is released.
The information provided does not constitute a diagnosis of your condition. You should consult a medical practitioner or other appropriate health care professional for a physical examination, diagnosis and formal advice. Health24 and the expert accept no responsibility or liability for any damage or personal harm you may suffer resulting from making use of this content.
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