Intrauterine adhesion (IUA), and its severe form Asherman syndrome (Asherman’s syndrome), is a mysterious disease, often accompanied with severe clinical problems contributing to a significant impairment of reproductive function, such as menstrual disturbance (amenorrhea), infertility or recurrent pregnancy loss. Among these, its correlated infertility may be one of the most challenging problems. Although there are many etiologies for the development of IUA, uterine instrumentation is the main cause of IUA. Additionally, more complicated intrauterine surgeries can be performed by advanced technology, further increasing the risk of IUA. Strategies attempting to minimize the risk and reducing its severity are urgently needed. The current review will expand the level of our knowledge required to face the troublesome disease of IUA. It is separated into six sections, addressing the introduction of the normal cyclic endometrial repairing process and its abruption causing the formation of IUA; the etiology and prevalence of IUA; the diagnosis of IUA; the classification of IUA; the pathophysiology of IUA; and the primary prevention of IUA, including (1) delicate surgical techniques, such as the use of surgical instruments, energy systems, and pre-hysteroscopic management, (2) barrier methods, such as gels, intrauterine devices, intrauterine balloons, as well as membrane structures containing hyaluronate–carboxymethylcellulose or polyethylene oxide–sodium carboxymethylcellulose as anti-adhesive barrier.

The pregnancy patterns and other factors of live birth for patients with intrauterine adhesions (IUAs) were identified by analyzing the clinical features of pre-, intra-, and post-hysteroscopic adhesiolysis (HA).

Intrauterine adhesion after hysteroscopic myomectomy contributes to infertility, recurrent miscarriages, menstrual irregularities, and hinders pregnancy outcomes. The aim of this study was to apply the indwelling Malecot catheter in prevention of intrauterine adhesion after hysteroscopic myomectomy and to further evaluate the effectiveness of this approach with reported live birth rates in infertile patients who underwent subsequent infertility treatment.Seventeen patients with FIGO Classification System PALM-COIEN Type 0 or 1 submucous myoma that received hysteroscopic myomectomy were recruited in this retrospective analysis. Post-operative insertion of the Malecot catheter via the aid of the uterine sound was performed and the catheter was left in place for seven days.The mean duration of TTP (time to pregnancy) was 15.6 months after hysteroscopy. Within three years after the operation, 10 out of 17 infertility patients achieved ongoing pregnancy over 12 weeks. Ongoing pregnancy rate was 58.8% (10/17). Eight patients achieved live birth (seven singletons, one twin pregnancy) with mean gestational age of 38 weeks. Live birth rate was 47.1% (8/17).The Malecot catheter is an inexpensive, easy-to-operate, and effective physical barrier method for preventing IUA in infertile patients undergoing hysteroscopic myomectomy with high live birth rate and no obvious visible post-operative adhesions.Copyright © 2020. Published by Elsevier B.V.

Intrauterine adhesion (IUA) is one of the most common diseases of the reproductive system in women. It is often accompanied by serious clinical problems that damage reproductive function, such as menstrual disorder, infertility, or recurrent abortion. The clinical effect of routine treatment is not ideal, and the postoperative recurrence rate is still very high. Therefore, exploring the pathological mechanism of IUA and finding new strategies for the effective prevention and treatment of IUA are needed. The main pathological mechanism of IUA is endometrial fibrosis and scar formation. Noncoding RNA (ncRNA) plays an important role in the fibrosis process, which is one of the latest research advances in the pathophysiology of IUA. Moreover, the exosomal miRNAs derived from mesenchymal stem cells can be used to improve IUA. This paper reviewed the role of ncRNAs in IUA pathogenesis, summarized the core pathways of endometrial fibrosis regulated by ncRNAs, and finally introduced the potential of ncRNAs as a therapeutic target.

Intrauterine adhesions are a severe complication after miscarriage. Hyaluronic acid gel has been used to prevent intrauterine adhesions after miscarriage.To systematically evaluate the efficacy of adjuvant therapy with hyaluronic acid gel to prevent intrauterine adhesions after miscarriage.The Cochrane Library, Embase and PubMed databases were searched for articles published before 31 July 2018 using the terms: ('hyaluronic acid gel' or 'gel') and ('dilatation and curettage' or 'D&C' or 'abortion' or 'miscarriage' or 'hysteroscopic') and ('intrauterine adhesions' or 'Asherman syndrome' or 'IUA' or 'endometrial injury' or 'intrauterine adhesion').Randomized controlled trials of hyaluronic acid gel therapy after miscarriage.Four studies were included in the meta-analysis (625 patients in total). Dichotomous outcomes were expressed as relative risk (RR) with 95 % confidence intervals (CI). Continuous variables were expressed as standardized mean differences (SMD).Hyaluronic acid gel reduced the intrauterine adhesion scores after miscarriage (SMD -0.68, 95 % CI -1.08～-0.28; p = 0.0008) and the incidence of postoperative intrauterine adhesions after miscarriage (RR 0.44, 95 % CI 0.29～0.67; p = 0.0001). Subgroup analysis found that hyaluronic acid gel reduced the incidence of moderate and severe intrauterine adhesions after miscarriage (RR 0.18, 95 % CI: 0.07～0.47; p = 0.0004), but had no effect on the incidence of mild intrauterine adhesions (RR 0.77, 95 % CI 0.42～1.19; p = 0.19). Hyaluronic acid gel also improved the pregnancy rate after miscarriage (RR 1.94, 95 % CI 1.46～2.60; p < 0.00001).Hyaluronic acid gel significantly reduced the incidence of moderate and severe intrauterine adhesions and significantly improved the pregnancy rate after miscarriage.Copyright © 2019 Elsevier B.V. All rights reserved.

To evaluate whether the cross-linked hyaluronan (cHA) gel can improve the clinical pregnancy rate of patients with moderate to severe intrauterine adhesion (IUA) who underwent operative hysteroscopy followed by embryo transfer.Women with moderate to severe IUA desiring to undergo embryo transfer were recruited in this randomized controlled trial. The patients were randomized on the day of receiving hysteroscopy. The control group received standard hysteroscopy, while cHA gel was applied to the treatment group at the end of hysteroscopy and 5-7 days after operation. All patients were expected to undergo in vitro fertilization (IVF)/intracytoplasmic sperm injection and frozen-thawed embryo transfer (FET).A total of 306 patients were enrolled in this study, of which 202 were assigned to the treatment group and 104 to the control group. Both the clinical pregnancy rate (26.3% [49/186] vs. 15.3% [13/85], P = 0.045), the implantation rate (17.7% [57/322] vs. 9.8% [15/153], P = 0.025), and the endometrial thickness on the day of embryo transfer (7.97 ± 1.37 vs. 7.50 ± 0.60 mm, P < 0.001) were significantly higher in the treatment group compared to the control group. In addition, histological assessment of the paired endometrial tissues collected before and after operation revealed a relatively higher number of tubular glands after operation (15.1 ± 13.2 vs. 28.8 ± 30.4, P = 0.166).To conclude, the application of cHA gel in patients with moderate to severe IUA during hysteroscopy can improve the quality of endometrium and uterine receptivity and consequently enhance the clinical pregnancy rate after IVF/CSI and FET.