HELSINKI, FINLAND – Scratching the endometrium to create a “favorable inflammation” may improve the likelihood of embryo implantation in subfertile women trying to conceive either naturally or by intrauterine insemination, according to a Cochrane review.
The “injury” caused by the process, which is known as endometrial scratching, has been reported to increase the probability of pregnancy in women undergoing in vitro fertilization, especially those with recurrent implantation failure. The inflammatory response to the injury, which is performed by pipelle biopsy or a similar device, is thought to make the endometrium more receptive to implantation.
In the current meta-analysis and systematic review of eight trials comprising 1,180 women, endometrial scratching appeared to approximately double the chance of clinical pregnancy and live birth/ongoing pregnancy (relative risk, 1.92 and 2.26, respectively), compared with either no procedure or a placebo procedure, lead author Sarah Lensen reported in a poster at the annual meeting of the European Society of Human Reproduction and Embryology.
The difference between the groups was statistically significant.
The evidence suggests that endometrial scratching would increase the normal chance of a live birth or ongoing pregnancy over a set period of time from 9% to between 14% and 28%, explained Ms. Lensen, a PhD candidate at the University of Auckland, New Zealand.
No evidence was seen that endometrial scratching has any effect on miscarriage, ectopic pregnancy, or multiple pregnancy.
Pain during the procedure was reported in one of the eight studies, in which the average pain score was 6 out of 10.
Endometrial scratching is a simple and inexpensive procedure that can be conducted without analgesia during a short clinic visit, although the internal examination that is required can be associated with pain and discomfort, Ms. Lensen said.
For the review, she and her colleagues looked at randomized controlled trials evaluating endometrial scratching in women planning to have intrauterine insemination or attempting to conceive spontaneously (with or without ovulation induction), compared with either no intervention, mock intervention, or endometrial scratching performed at a different time or to a greater or lesser degree.
The researchers acknowledged that the quality of the evidence is quite low, with a risk of bias associated with most of the included trials. For this reason, the results should be viewed with caution, they said.
“High quality randomized controlled trials which recruit sufficient numbers of women are needed to confirm to refute these findings,” they wrote.
Ms. Lensen reported having no financial disclosures.