Health · 6 Aug
Cochrane: no reliable evidence that common embryo-transfer preparation techniques improve IVF success
A new Cochrane systematic review pooled 11 trials covering 2,524 women and found no reliable evidence that three routine embryo-transfer preparation techniques improve pregnancy rates: arriving with a full bladder to straighten the utero-cervical angle, removing cervical mucus before transfer, and "afterloading" to guide the embryo through the cervix. The included trials were small and methodologically weak, so the evidence was rated low or very low certainty.
For someone going through IVF, the practical takeaway is that these routines reflect tradition, clinic protocol and clinician preference rather than demonstrated benefit. There is no evidence-based reason to pay extra for them, and no evidence that skipping them lowers the chance of success; the techniques are generally considered safe, with a full bladder's discomfort the main downside.
The review authors recommend none of the techniques over standard care and call for properly powered trials, noting that 16 years of research have not settled the question. All included studies were conducted in high-income countries, so findings may not transfer elsewhere. This is an absence of evidence, not proof the techniques fail.