Thread: FETs in older women

I have a question regarding success rates for FETs in women over 40. In looking at the national SART data, I noticed that compared to same age fresh cycles, success rates for FETs tend to be lower for younger women (under 40), but oddly, higher for older women.

For example, for women under 35, the success rate for a fresh cycle with 2 embryos transferred is 47.5%, and for a FET (same # of embryos), 35.6%. However, for a women older than 42, the success rate for a fresh cycle with 3.1 embryos transferred is 6.2%, but for a FET with fewer embryos transferred (2.3), the success rate jumps to 13.9%! This is national data, so comparison is among large groups of women (no less than 961 in each group), so I’m guessing that the stats are reliable.

What accounts for this odd jump in success rates for FETs in older women? Is it simply that the women who end up with embryos to freeze are by definition more “fertile” (lower fsh, higher antral count, better egg quality)? Or could it be something external; perhaps the high doses meds given to women in their 40s have a negative impact on the endometrium? (I actually talked with a doctor who felt that this was the case—he only does low dose IVF). Do you think it’s possible that higher doses of FSH could impact endometrial health and implantation?

Thanks very much!
Sophie