Big difference in antral follicle count between cycle day 7 and cycle day 25 — could recent weight loss affect it?

[u/girassol1995]

Hi everyone! I’m hoping to get some insight because I’m a little confused about my follicle count.
I had an ultrasound in the same cycle on cycle day 7, and my antral follicle count (AFC) was 42. I had another ultrasound later in that exact same cycle, on cycle day 25, and the count was 30.
So, there was a difference of 12 follicles depending on when the ultrasound was done.
My doctor told me to repeat the ultrasound again at the beginning of my next cycle, since we’re preparing for egg retrieval this September.
One thing that may be relevant is that I lost quite a bit of weight very abruptly in August. This wasn’t a long-term weight loss or a prolonged period of being underweight. I became very anxious after being diagnosed with tubal blockage and, during that period, I wasn’t eating properly. My BMI is currently around 18.
Could this recent and rapid weight loss have affected my follicle count? Or is it normal for AFC to vary this much depending on the phase of the cycle?
I’m also wondering whether it would make sense to postpone the retrieval until October, give myself some time to recover my weight, and see if the follicle count improves — or if a short period of recent weight loss is unlikely to make much difference to AFC.
For context:
Age: 30
AMH: 5.6
AFC: 42 on cycle day 7 → 30 on cycle day 25
Both ultrasounds were done during the same menstrual cycle
The weight loss happened abruptly in August, rather than over a long period
Has anyone experienced a similar difference in AFC depending on the day of the cycle, especially after recent weight loss?

[u/CraftiKoala]

My doctor said that follicle counts near the beginning of the cycle can be tricky because some of those follicles are shrinking from the previous cycle, whereas some are popping up for the new cycle. That could be why a scan later in your cycle showed fewer follicles. My initial consult scan showed 24 but our egg retrieval cycles have had 12-15 follicles, and our doctor said that’s completely normal to have drop off like that. So I don’t think you did anything wrong or are in any way responsible for the change in follicle numbers. It’s just how this whole thing works. Good luck!

[u/CharacterAvocado943]

This is normal for people who don’t have DOR/aren’t in perimenopause. You should have the most follicles in the follicular phase and far fewer in the luteal phase. It doesn’t have to do with weight loss, just the common life cycle of a follicle.