More Lovely Numbers – From the CDC
Finally found some data regarding the different success rates, here from the CDC (section C). What I have not found however is anything showing the differences between day 3 and day 5 transfers while comparing the same number of embryos transferred. These are just overall numbers, so you don’t know if the different success rates are because people are transferrring more or less embryos or not.
The page linked to contains data regarding
- How many embryos are transferred
- How many transfers are day 3 and how many are day 5
- The success rate of day 3 transfers vs day 5
- How many embryos are transferred on day 3 vs day 5
- http://www.cdc.gov/ART/ART2004/section2c.htm#f35
All of the data is from 2004 though. I know success rates have changed significantly since then. It is just so hard to find relevent data, since so many factors affect the success rate: the age of the mother; the cause of infertility; the quality of the embryos; the number of embryos transferred; the day of the transfer. So while I’m able to find data that considers one or two of those factors, I have yet to find any data that takes into consideration all of them. (I know that would be a huge undertaking for any type of researcher, though.)
Oh I should have been an accountain or statistician or something. I can’t help it, numbers make me giddy. (I’m a computer programmer instead, LOL)
Hi there,
Just wanted to put in my two cents about 3 day vs. 5 day transfers.
In a good laboratory, they should have better success rates for 5 day transfers. It is thought that only the “best” embryos can make it to blastocyst stage, so any that do are more likely to be chromosomally normal, and therefore implant. In addition, it is easier for the embryologists to “rate/grade” embryos at blast stage, so the selection process of the ones to choose for transfer usually results in better stats because the best are easier to identify.
Lastly, fewer embryos are transferred in day 5 vs. day 3, as you saw in the CDC stats, which results in less high-order multiple births.
Here’s what my clinic/lab says about blast transfers: http://www.2reproduce.com/blast.html
Hope this helps in your decision-making process.