NYU School of Medicine
CCRM New York
Not all embryo transfers are of the same difficulty and not all doctors are equally competent at performing them. A good cycle can be ruined by a bad transfer and so it’s important you understand who is doing your transfer.
First, as you can see below, some transfer cases are more difficult than others and the challenging cases result in lower pregnancy rates. While some patients (e.g. obese patients, those with previous C-sections) more often represent difficult transfers, it’s hard to be certain if you’ll be a hard case and so you want the best doctor available performing your transfer.
Unfortunately, most patients will not have their fertility doctor perform their transfer. We see this especially often in clinics that do over 300 cycles per year and in clinics with an academic affiliation.
As a result, there is a good chance a different doctor at your clinic will perform your transfer. Even within the same clinic, doctors have varied abilities. Below you’ll see how 11 different transferring doctors at RMA New Jersey perform. The best performer has a 16% absolute higher percentage Live Birth Rate (67% vs. 51%) than the least successful performer. Roughly 90% of clinics report they regularly track this data and most tell us these discrepancies are commonplace.
When the ASRM dug into this issue, they surfaced a set of facts that show best practices are slow to diffuse: 25% of recent fellows have never done a single transfer, the majority of fertility doctors will not ask for help with a transfer, and most clinics do not impose standard transfer protocols on their doctors, even those who fall below thresholds.
To improve standardization the ASRM issued guidelines for how transfers should be carried out. We suggest you ask your doctor early on in the process if they plan to comply with these standards and we recommend you re-familiarize yourself with these leading up to the transfer.
One subject the ASRM guidelines do not address is the “mock transfer” whereby a doctor does a practice transfer (without embryos in the catheter) so they can measure the woman’s anatomy and anticipate challenges. This can be done weeks, or minutes, before the the actual transfer.
There is little data clarifying if doing a mock transfer helps. One clinic, back in 1990, reported doing a mock transfer reduced the number of transfers it considered “challenging” and improved pregnancy rates. We’ve yet to hear doing a mock transfer causes harm and so we suggest asking your doctor if they think it will help.