Endometrial scratching to increase embryo implantation

One of the most frustrating problems in IVF today is failed implantation. When we transfer perfect looking embryos into a normal uterine cavity, we expect that the patient will get pregnant. When they don’t , it’s hard to figure out what the reason for the failed IVF is.

We know that many Grade A embryos will have a lethal genetic abnormality which will prevent them from implanting. However, we cannot diagnose these, even with the newest genetic technology such as array CGH ( comparative genomic hybridisation) and NGS ( next generation sequencing) . This is because while these tests allows us to check for the number of shape of chromosomes, they do not allow us to screen for problems at the gene level. This is why even embryos which have been proven to be normal on CGH will still fail to implant.

However , rather than fretting about all the things which we cannot control, in clinical practice it makes much more sense to can be focus on some of the things which we can improve in real life.

One of the ways we can improve IVF success rates is by enhancing endometrial receptivity. This is why we monitor endometrial thickness and texture by ultrasound scanning; and this is why we provide luteal phase support after the transfer with estrogen and progesterone.

One of the interventions which has been recently proposed to enhance endometrial receptivity is the technique called endometrial scratching.  This is an extremely easy and inexpensive intervention , in which we injuring the uterine lining in a very controlled fashion. This might sound very counter-intuitive – why would one want to actually inflict damage on the endometrium ? Conceptually, this is like the old-fashioned D&C which gynecologists used to use in the past to “ treat “ unexplained infertility, but it’s much less invasive. Instead of scraping the uterine lining ( as we do in a D&C), in a scratch procedure we just introduce a file plastic catheter into the uterus, in order to remove a small strip of the uterine lining. ( The additional benefit this procedure offers is that it allows us to map the cervical canal , and since it’s very similar to a dummy embryo transfer, it makes the actual ET much easier).

How does this help ?

We know that every time the body sustains an injury, the body’s healing systems mount an inflammatory response to allow the injured tissue to heal. One of the mechanisms is to increase local blood flow, and we believe that controlled endometrial scratching serves exactly the same purpose, thus allowing the uterine lining to enhance its receptivity.

This is easy to do, and while it’s hard to document that this procedure improves IVF success rates because enough controlled clinical trials have still not been done, it’s worth offering to patients who have failed IVF cycles earlier,  on an empirical basis. It’s a low-cost procedure, which is unlikely to cause any harm, and may be worth trying.