Intrauterine adhesion (IUA) is the adhesion of intrauterine tissues due to the exposure of myometrial tissues caused by the endometrial basal injury. IUA is clinically manifested as symptoms such as abdominal pain, hypomenorrhea or amenorrhea, sterility and habitual abortion, which seriously affect the patients quality of life.

Preventing IUA has been tried using different methods such as barrier or stent in order to separate the opposing endometrium during the tissue healing processes. Although some successes have been reported there are still some challenges need to be dealt with.

One of the barrier materials for preventing IUA is made of hyaluronic acid (HA). HA is a natural ECM of human tissue with excellent biocompatibility and promotes the scar-free wound repair. The self-crosslinked esterified HA gel has demonstrated the capacity to prevent IUA in clinical studies.

A novel self-crosslinked HA gel is developed by BioRegen Biomedical（Changzhou）Co., Ltd with proprietary technologies. This product is a highly viscoelastic crosslinked gel that overcomes the shortcoming of sodium hyaluronate with high motility and too quick degradation in vivo. For this product, the results of animal experiments and various safety features have been designed and tested conforming to the national regulations and standards. In order to launch this product to the market, this prospective, randomized and controlled clinical trial is designed and will be performed to verify its safety/efficacy.

Inclusion Criteria:

• Female patients who are 20-40 years old who is diagnosed as intrauterine adhesion, and did not receive adhesiolysis surgery.
• Patients who signed the informed consent form (ICF) and agreed to take contraceptive measures within 3 months after the surgery.
• Physical examination and routine laboratory tests demonstrated no systemic diseases.
• According to the AFS scoring system on the IUA (1988) only those patients with moderate to severe IUA (i.e. total AFS score larger than 4 points) were enrolled in this clinical trial.

Exclusion Criteria:

• Patients who is allergic to hyaluronan or its derivatives.
• Patients with inflammation of reproductive organs, pelvic cavity inflammation, malignant tumor of reproductive organs and other systemic diseases that could cause metrorrhagia.
• Patients with malformation of reproductive organs.
• Patients who may not take effective contraceptive measures within 3 months after the surgery. Patients who were suffering severe systemic diseases such as coagulative disorders, cardiovascular diseases and long-term alcoholism and drug abuse were also excluded from this clinical trial.