The new buzz word in the world of IVF in recent months is “endometrial scratching”. It has been reported to increase pregnancy rate as much as 20%, according to a recent publication. (1) Suddenly, every IVF patient is asking about endometrial scratching.
So, exactly what is endometrial scratching? Well, it is exactly what it means, gently scratching the lining of the uterus using a fine “pipelle” catheter pass through the cervix. Other terms used are “endometrial scraping” or “endometrial biopsy”.
Endometrial scratching is not a new concept. The experienced gynaecologist would tell you D & C (dilatation and curette) can improve pregnancy rate. The link between endometrial scratching and improve pregnancy rate in subsequent ART (artificial reproductive treatment) was first described more than ten years ago. Cochrane review, considered to be the highest level of research by the medical profession, published in 2012 summarised the currently available evidence on endometrial scratching and suggested that, the procedure doubled the chances of pregnancy and live birth after IVF treatment. The review, however stress that the evidence of benefit was restricted to women who had undergone previous unsuccessful IVF or ICSI cycles.
A recent randomised study published in September 2013 looked at endometrial scratching for all women undergoing ART. Their findings suggest that endometrial scratching done 7 to 14 days before the start of IVF cycle, increase the chance of pregnancy and live birth rate. Clinical pregnancy rate was 49% in the endometrial scratch group and 29% in the sham procedure group. The study was terminated prematurely because of the significant difference in the outcome.
How does endometrial scratching improve pregnancy rate? Researchers can’t tell us the exact mechanism, but we believe it has something to do with improving endometrial receptivity to embryos implanting. By causing an injury to the endometrium, the healing process that follows improves the signalling system within the endometrium, and allowing better synchronicity between endometrium and the implanting embryo.
How is endometrial scratching done? It can be done as outpatient or as an office procedure. A fine pipelle catheter is passed through the cervix and three or four strips of endometrium scraped off. During the procedure, some women might experience period cramps, and oral analgesia such as paracetamol is advisable. However, in majority of cases, the procedure is tolerated very well.
Finally, a word of caution for women considering the procedure, will it work for me? In the study published in September, the women studied were all under the age of 38. So, outcome for the older age group women is unknown. The study shows improvement in pregnancy rate from 29% to 49%. At Genea, our pregnancy rate is 46% for women under 38 (2011 internal data). Will addition of endometrial scraping further improve our pregnancy rate? Only time will tell, as fertility doctors move into a new era of performing routine endometrial scratching before the start of IVF treatment.
1: Endometrial scratching performed in the non-transfer cycle and outcome of assisted reproduction: a randomized controlled trial. C. O. NASTRI, R. A. FERRIANI, N. RAINE-FENNING & W. P. MARTINS. Ultrasound Obstet Gynecol 2013; 42: 375–382