Question on Follicle Size
6 Replies
Becca - July 20

Hi Ladies! This is my first month going to an RE. I had my u/s done last Monday and there was 1 follie developing on the left ovary that measured 15mm. They said it would grow about 2 mm a day and that I would O on wednesday or thursday. I went back in for another u/s on wednesday and the follie was only 15.5mm and the nurse told me it had already begun to rupture because of the fluid behind my ovary. They did blood work and told me that I would be Oing on Thursday night. I have 2 qustions. 1. Is it ok that my follie didn't grow to the full 18-21mm before rupturing? Does that mean it's not mature enough to be viable? Second question is, how reliable is the u/s and blood work at pinpointing O? My temps have been all over the place and I didn't get a thermal shift until I started using progesterone cream, so I'm wondering if I didn't O or if I O'd much later? Does anyone have much experience with this? Thanks!!!


linds99 - July 20

It doesn't matter that your egg didn't grow to the 18-21 mm range. A 15 is still considered a dominant follicle. I read on the internet that some doctors believe that follicles that get to the 20 mm range start to degrade, and they speculate they may not be as viable. So I would not worry too much about your size, it sounds normal. If you are on Clomid, your temps will be crazy. Ultrasound work is waaaay more correct then temps anyway, as they can measure the endometrial lining too. It sounds like your low progesterone problems could be a contributing factor to you not getting the normal thermal shift...that is ok too. The cream will supplement that. I had three follicles on my right ovary about 9 days ago when they triggered them with the HCG shot (20 mm, 15.5, 14.5) and the left one had two (20.5 mm, 14.5 mm). They considered all these dominant, but the nurse said more than likely 60% of them had an egg that would release. So, based on my experience, your follie sizes are fine.


Becca - July 20

Thanks so much linds, you sound very like you know a lot about this stuff. I'm stil new to the RE, so I'm trying to get a handle on everything that's going on. I was starting to worry, but I feel a lot better now. Thanks so much! No, I'm not on clomid this month, so I don't know why my temps are crazy. Maybe I have a progesterone difficency. I tried it for a month and it was no good for me, so my RE wants to try me on a different med next month. Here is my chart if you want to take a look My RE said I would O on the evening of cd 18 based on my u/s and bloodwork.


linds99 - July 21

Hi Becca, I posted an article regarding fat in our diets. Sometimes our hormonal imbalances (especially when we are young like this and pre-menopause) are attributed to low fat diet (not enough good fat). We need cholesterol ( a healthy amount) to produce the right amount of estrogen and progesterone everymonth. Perhaps you should examine your diet more closely and see what you are not doing or doing too much of. For myself, I believe I have stupidly abandoned cholestrol-ran from it thinking fat will give me heart disease. The truth is that we do need a good level to maintain fertility and balance. I say ovulation on CD 18 sounds promising for you! I hope you guys catch it this time...


linds99 - July 24

Becca- I just found this on a fertility website. A lead follicle should be at least 16 mm on an hMG like Pergonal, it should be at least 18 mm on a recombinant FSH like Gonal-F, and should be about 22 mm on Clomid. Occasionally Gonal-F can produce mature eggs in smaller follicles, in which case other measurements such as E2 and progesterone should be used to indicate maturity. (The difference in ideal size is due to the difference in mechanisms by which the medications work. For example, the mechanism by which Clomid works often takes a bit longer because it is indirect. Therefore, the follicle has more time to grow before the egg is actually mature). Follicles grow 1 to 2 mm a day both while taking ovulatory stimulants and after the HCG shot. "Will smaller follicles "catch up" in time to release eggs?"...the article says that Follicles generally need to be at least 15-16 mm to contain fertilizable eggs (although it is possible in rare cases for follicles to be as small as 14 mm and still contain fertilizable eggs). If the smaller follicles are close in size to the lead, they may "catch up" and release. HCG will usually result in most mature follicles releasing eggs. Otherwise, most likely only the lead follicle will ovulate.


lucy206 - July 26

Hi Ladies - reading this site has been very helpful. I will be giving myself the trigger shot either tonight or tomorrow - waiting for the doctor to call me and let me know when I should do it. This morning I had 3 follicles on the right the number was 13 on the left was 15 and another 15. I'm a little nervous. Also - as far as ovulation - they say it occurs 36 hours later (after the shot). Should I be having intercourse from when I do the shot to about 72 hours later?


Aisham - October 25

Hi there
I now this is an old forum.
But I was just wondering how you got on as I'm in a similar situation as you xx



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