As I mentioned previously, we decided on a Mini-Stim protocol for this IVF round. I developed one dominant follicle and then about 6 smaller ones. I triggered using hCG.
34.5 hours after the trigger shot, I went in for egg retrieval.
Going in I knew I only had one large antral follicle of >18mm. I knew there was going to be a less than 10% chance of getting a viable embryo at the end of this. What are the chances of getting zero oocytes?
For me, that was where the attrition from 10% to 0% was - right at egg retrieval. No ability to know maturity, no ability to know if it would fertilize, or cleave, or grow to the blastocyst stage.
It is disappointing, but not surprising.
Since I had that one large follicle it was likely suppressing the smaller follicles from growing. There is going to be a local effect, that is what the dominant follicle does. The estrogen (and inhibin) produced from that large dominant follicle blocks FSH from binding to the subordinate follicles. That’s natural physiology.
My Master’s research group (dubbed the One Reproductive Health Group) was one of the founders of follicular aspiration, along with O.J. Ginther, as a means for starting the growth of the next wave of follicles or wave emergence as we call it. The aspiration of the dominant follicle will remove the estrogen and inhibin signal and then those smaller follicles can grow. When my research group synchronizes wave emergence now, we almost always use follicular ablation (ultrasound-guided follicle aspiration); typically of the larger than 5 mm follicles, but other research shows you only need to aspirate the two largest follicles to get the smaller follicles to start growing synchronously.
We can continue to stimulate those follicles with FSH injections. In fact, our group also demonstrated that there were more large antral follicles when given seven versus four days of FHS injections, which ultimately results in greater number of transferrable embryos. My colleague and friend recently published on follicle recruitment in prepubertal calves. (For those reading from India, our group also demonstrated this in Water Buffalo).
I should also mention that, in cattle, it has been proven that if you start the FSH injections prior to selection of the dominant follicle, at the time of wave emergence, you will have a better response, as measured by the number of follicles ovulated (or superovulation).
So what does this all mean for me? The goal is to try and grow those smaller follicles now that the one larger one is gone.