Endometrial intravascular thrombi are typically associated with shedding but may be the sentinel feature of an underlying thrombotic disorder

A randomized, controlled clinical study of low-molecular-weight heparin improving pregnancy outcomes in PCOS women undergoing IVF: study protocol

BACKGROUND

Polycystic ovary syndrome (PCOS), an incidence of 10-15% in women of reproductive age, shows sex hormone disorders, luteal insufficiency, and the tendency of placental villus space thrombus. The incidence of early pregnancy loss in women with PCOS is three to eight times higher than that in non-PCOS women. PCOS women were reported in a pre-thrombotic state, which was manifested by accelerated thrombin production, increased PAI-1 activity, and fibrinogen. Other research also found an over-activated state of women with PCOS in immune system. Therefore, changing the prethrombotic state of PCOS through anticoagulation may be a new way to improve the adverse pregnancy outcome of PCOS. Low-molecular-weight heparin (LMWH) is the most common used anticoagulant drug in pregnancy, and it also was proposed for the prevention of recurrent abortion, although the application of LMWH in PCOS population during early pregnancy has not been reported. The objective of this study is to investigate the effect of LMWH on pregnancy outcomes after invitro fertilization-frozen embryo transfer (IVF-FET) in patients with polycystic ovary syndrome.

METHODS

A total of 356 PCOS women aged between 20 and 38 years which prepared for IVF followed with FET will be enrolled in the study. The patients, from four different hospitals stratified by age and body mass index (BMI), will be randomly divided into the study group who will be treated with LMWH started on the day of progesterone transformation (hormone therapy) during FET cycle and the control group without additional medicine. Serum or urine hCG test will be given 14 days after embryo transfer to confirm biochemical pregnancy. If pregnancy is positive, LMWH+ hormone therapy/hormone therapy will be continued for another 2 weeks. Transvaginal ultrasonography will be performed 14 days later to confirm intrauterine pregnancy. The primary outcome is the ongoing pregnancy, which is defined as intrauterine live fetus with ultrasound after 12 weeks of gestation.

DISCUSSION

This is the first study protocol to investigate the efficacy of LMWH as an adjuvant drug for IVF-FET outcomes in PCOS women, by comparing differences in ongoing pregnancy rate, clinical pregnancy rate, live birth rate, and early pregnancy loss rate between LMWH group and the control group.

TRIAL REGISTRATION

ClinicalTrials.gov ChiCTR2000036527. Registered on August 24, 2020.

Effect of Blood Gel Derivatives on Wound Healing in Mouse Injured Tissue Models

Several previous studies in the field of assisted reproduction have focused on the use of blood gel derivatives, such as platelet-rich fibrin (PRF), as a treatment for endometrial rehabilitation. However, the ability to release growth factors and the gel form of this product led to the evolution of platelet lysates. In this study, blood gel derivatives, including PRF lysate, which was in liquid form, and PRF gel, were collected and evaluated for growth factors. It was shown to be effective in endometrial wound healing and regeneration in mouse injured uterine tissue models through structure and function (pinopode expression, embryo implantation) evaluation. The results demonstrated that the concentrations of growth factors, including PDGF-AB and VEGF-A, were higher in the PRF lysate compared to the PRF gel (p < 0.05). PRF lysate could release these growth factors for 8 days. Furthermore, both PRF gel and PRF lysate restored the morphology of injured endometrial tissues in terms of luminal and glandular epithelia, as well as uterine gland secretory activity. However, the presence of pinopodes and embryonic implantation were only observed in the PRF lysate group. It can be concluded that PRF lysate promotes wound healing in mouse injured tissue models in vitro, which can act as healing products in tissue repair.

Platelet-rich fibrin improves repair and regeneration of damaged endometrium in rats

Purpose

Intrauterine adhesion (IUA) is the most common cause of uterine infertility. This study aims to evaluate whether platelet-rich fibrin (PRF) treatment can stimulate damaged endometrium regeneration in rats.

Methods

First, hematoxylin and eosin (HE) staining, scanning and transmission electron microscopy, and ELISAs were used to evaluate the microstructure of PRF. Then, mechanical damage was used to establish an IUA rat model. A total of 40 SD female rats were randomized to three groups: PRF transplantation group, IUA group, and sham group. Rats were sacrificed at 3, 7, and 14 days and uteruses were obtained for further analysis. Finally, functional and histological recovery of the damaged endometrium was analyzed by pregnancy test, HE staining, Masson's staining, and immunohistochemistry.

Results

PRF has two distinct zones, platelets and fibrin zone. Long and narrow fibrin fibers interconnected with each other and formed a three-dimensional, flexible, and elastic structure; platelet aggregates were trapped in fibrin fibers, and each platelet is associated with several fibrin fibers. PRF exudates promoted endometrial stromal cell proliferation and migration in vitro. PRF transplantation was beneficial for maintaining uterine structure, promoting endometrial luminal epithelium and endometrial gland regeneration, and decreasing fibrotic areas in vivo.

Conclusion

Intrauterine administration of PRF was demonstrated to be effective in preventing IUA and stimulating damaged endometrium regeneration in rats. This study not only provided a promising method for its potential in endometrial regeneration in women who suffer from uterine infertility but also may prevent IUA after intrauterine surgery in clinical cases.