Endometrial scratching in women with one failed IVF/ICSI cycle-outcomes of a randomised controlled trial (SCRaTCH)
A large multicentre, non-blinded, randomised control trial was conducted to test if (mid-luteal phase) endometrial scratching in women, after one failed IVF or ICSI cycle, changed the probability of having a live birth in the following fresh IVF or ICSI cycle.
A total of 1071 women were recruited, across 32 hospitals in the Netherlands, with a final number of 933 women completing the trail as per protocol and included in the analysis. Per group, 448 women received the endometrial scratch, and 461 women did not (Control). Median pain level of the procedure, reported using a visual analogue scoring system, was 4.5/10. A week after the procedure 53.9% of women reported symptoms of blood loss, abdominal pain and or fever, however none required antibiotics or hospitalisation.
After twelve months post randomisation followed by IVF / ICSI treatments, initial intention-to-treat analysis showed that live birth rates following second fresh IVF / ICSI treatment was not significantly different, 23.7% vs 19.1%, between the scratch group vs control, respectively. Biochemical pregnancy loss was reported as 17.6% vs 14.6% and miscarriage rates in 11.1% vs 15.3%, between the scratch and control group respectively.
As-treated statistical analysis produced similar but different results, regarding live births (28.0% vs 22.2%), biochemical pregnancy loss (16.8% vs 14.3%) and miscarriage rates (10.9% vs 15.6%), between the scratch and control groups respectively. Implantation rate followed a similar trend, 27.8% vs 24.0%, between scratch and control groups.
Although the live birth rate was 4.6% higher in the endometrial scratch group this was not statistically significant since the study was only designed to detect a difference of 9%. The true effect of endometrial scratching on live births lies in the range of -0.7% to +9.9% according to this study. A much larger study is required to validate the exact difference.
SUMMARY: SHOULD YOU HAVE AN ENDOMETRIAL SCRATCH
This randomized control trial, comparing endometrial scratch to no scratching, in women before their second IVF or ICSI cycle, found no statistically significant increase in implantation rates, clinical pregnancy or live births rates, in the 12 months following endometrial scratching.
- Non-blinded trial
- Insufficiently powered to detect significant differences
Lensen S, et al. (2019). A Randomized Trial of Endometrial Scratching before In Vitro Fertilization. https://doi.org/10.1056/nejmoa1808737
Olesen M S, et al. (2019). Therapeutic endometrial scratching and implantation after in vitro fertilization: a multicenter randomized controlled trial. https://doi.org/10.1016/j.fertnstert.2019.08.010
Mak J S, et al. (2017). The effect of endometrial scratch on natural-cycle cryopreserved embryo transfer outcomes: a randomized controlled study. https://doi.org/10.1016/j.rbmo.2017.04.004
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