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10 Nov 2020

Natural cycle Day 13 ovulation with 16mm follicle
Hello and thank you so much for your help! I am being monitored for a natural cycle after two "chemical pregnancies" in the course of four months. I am also taking medication for high prolactin and TSH levels. Today, I had a day 13 scan that showed my largest follicle was 16mm. Cervical mucus in the cervix indicated estrogen levels were good. My lining was on the thin side at 5.something mm, but had the right pattern. Monitoring doctor said it looked like I would ovulate in 2-4 days. My bloodwork, however, showed I was ovulating now. My hormone levels were: Estragon -- 166; Progesterone -- 1.1; LH -- 37. What does it mean that I ovulated a small follicle??? Does the thickness of my lining put me at risk for implantation failure (if the egg turns out to be viable)? Any help would be greatly appreciated. I am wracked with nerves!!
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Fertility expert
Fertility expert

23 Nov 2020

Dear Elizabeth,

You would not have ovulated a “small” follicle. One will spontaneously ovulate when the follicle is approx. 20-22mm, and the average follicle growth rate is 2mm per day. I agree with your doctor that you would have been ovulating in the next few days. Once an LH surge is detected, ovulation usually occurs 24-36 hrs later.

A thin lining can be a risk factor for failed implantation; however, as the egg grows, oestrogen levels will rise and this will cause the lining to grow too.


Answered by Dr T Mohamed

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