P-333 Thin endometrium, randomised clinical trial using plasma rich in growth factors
Authors: Castells I , Quintana F , Matorras R , Fernandez G , De la Fuente M , Ferrando M 
Published: June 2023

Abstract

Study question
Does the use of platelet growth factors instilled into thin endometrium in oestrogen-replacement treatment cycles improve endometrial thickness?

Summary answer
The use of growth factors in thin endometrium improves endometrial growth

What is known already
Thin endometrium impairs implantation rates and IVF outcomes. To date there is no effective treatment to improve the proliferation.
PRGF-Endoret is used in multiple clinical indications. The autologous collection of growth factors (PRGF), applied to the area to be treated, produces a controlled release of multiple molecules with regenerative capacity in the focus of the lesion.

Study design, size, duration
Prospective randomised clinical trial to determine the effects of PRGF-ENDORET therapy in patients with thin endometrium undergoing oestrogen treatment for embryo transfer.
Twenty-two patients were included from March 2018 to May 2021.
At the end of the trial, a complementary retrospective study was conducted analysing all the treatments of these patients without live birth(21) before and after participating in the study until December 2022. 15 embryotransfer in study group and 27 in control group.

Participants/materials, setting, methods
Patients of IVI Bilbao clinic with endometrium less than or equal to 5mm after 10 days of treatment.
PRGF was prepared according to the PRGF-Endoret technique using the medical device developed by BTI Biotechnology Institute.
The study group received three instillations of PRGF Endoret using a kitazato IUI cannula.
The first instillation was performed with in situ activated coagulum and the 2nd and 3rd instillations with PRGF-rich supernatants that were previously stored at -20 °C.

Main results and the role of chance
The clinical trial showed a significant increase in endometrial thickness 1.3 ± 0.67 mm compared to the control group of 0.58 ± 0.51 mm. Prior to treatment the mean endometrial thickness was 4.29 ± 0.88 in the control group and 4.44 ± 0.40 in the study group. After randomisation the mean was 4.87 ± 0.76 in the control group and 5.74 ± 0.87 in the study group.
2 pregnancies only in the study group and 1 live birth.
The retrospective study shows 0.7mm increase in mean endometrial thickness in the post-PRGF cycles in the study group patients. Of the 15 transfers that were performed a posteriori, there were implantation rate of 40% and a 20% live birth rate, 40% biochemical miscarriage and 20% clinical miscarriage, with a significant increase of 0.94mm compared to the endometrium of the instillation cycle.
In the control group of patients who received a posteriori factors there was also a significant increase in thickness of 1.6mm compared to the study cycle with an implantation rate of 58.33% and a 33% live birth rate, 58.33 biochemical miscarriage and 25% clinical miscarriage.
Comparing all the cycles of these patients before and after PRGF, no statistical significance was found, although there was an increase of 0.29mm.

Limitations, reasons for caution
The number of patients included was lower than initially planned, but once the statistical power was adjusted, its safety and efficacy was demonstrated.
More studies should be done to demonstrate when to instil, how many times, when transfer, but it is clear that it is safe and effective.

Wider implications of the findings
The use of factors has been shown to increase endometrial thickness. It could be thought to open the door to favouring endometrial receptivity and therefore live birth.

Trial registration number
2016-001716-38