P-739 Hysteroscopic metroplasty and thin endometrium, some new indication? Results of a multicenter retrospective study

Abstract Study question Is there a place for hysteroscopic metroplasty in the management of thin endometrium? Summary answer Hysteroscopic metroplasty appears to significantly improve the chances of live birth in a population of infertile patients with thin endometrium. What is known already A thin endometrium is found in 1 to 12 % of the cases for patient treated in an infertility center. When a thin endometrium is repeatedly observed there is no specific protocol for resolving the situation. Numerous study have been carried out on this subject but here is insufficient evidence to recommend a specific treatment because the results are inconclusive, or not strong enough. Hysteroscopic-metroplasty is use by several teams to treat infertile women with T-Shaped uterus. We assumed that metroplasty could improve results in patients with a thin endometrium by stimulating endometrial recolonisation as observed in cases of synechia section. Study design, size, duration This is a multi-center retrospective observational study conducted between 1er January 2015 and 31 December 2021 at the Clinique Mutualiste de la Sagesse, Rennes, France and in the University Hospital of the Kremlin Bicêtre, APHP, France. T-Shaped uterus was diagnosed by an ultrasound expert, and a thin endometrium was defined as an endometrium less than 7mm thick after a minimum of 14 days of well-conducted stimulation. Participants/materials, setting, methods Exclusion criteria were age < 18 years, previous hysteroscopic metroplasty, past history of more than one synechia treatment. The primary outcome was first live birth after surgery. Secondary endpoints were pregnancy rate and spontaneous pregnancy rate, surgery complications, neonatal outcomes. This retrospective study used data collected prospectively. Main results and the role of chance Our objective was to evaluate hysteroscopic metroplasty in the management of infertile patients with T-shaped uterus type dysmorphia and / or a thin endometrium. The primary endpoint was the occurrence of a live birth rate post-surgery. One hundred and forty five infertile patients were included, including 126 nulliparous women (86.9%). The post-surgery live birth rate was 40.7% during the total post-operative follow-up, with similar result in case of thin endometrium or in case of T-Shaped uterus. In terms of pregnancy, we recorded 75 post-surgery pregnancies (51.7%), of which one third was obtain spontaneously. The duration of infertility suffered by patients before surgery ranged from 1 to 7 years and the average duration of conception after surgery was less than 1 year. We did not raise any major per or post operative complication for both mother and the future baby. Hysteroscopic metroplasty appears to significantly improve the chances of live birth in a population of infertile patients with at least one uterine pathology such as T-shaped uterus or thin endometrium Limitations, reasons for caution This is a retrospective study, with all the biases that this implies. More robust studies are therefore needed before the practice can be generalised. Furthermore these results were obtained in 2 expert centres. Although the technique is easily reproducible, caution must be exercised before generalising it. Wider implications of the findings This study is the first one to the best of our knowledge to provide an opportunity to consider this new treatment option for thin endometrium, what is still an under-recognised pathology. Our results can be used to justify the initiation of a randomised controlled trial. Trial registration number not applicable