The septate uterus is the most common structural uterine anomaly. It results from failure of the partition between the two fused Müllerian ducts to resorb;it is associated with the highest incidence of reproductive failure and with first- and second-trimester pregnancy loss and infertility.

Hysteroscopic division of the uterine septum is performed using microscissors, electrosurgery, or laser. Several studies shown significant improvement in pregnancy outcome after hysteroscopic metroplasty.

Purpose of this study is to verify the effectiveness of 5 ml, instead of 10 ml, of autocross-linked hyaluronic acid gel in the prevention of the formation of intrauterine adhesions, through second look office hysteroscopy after three months.

Inclusion Criteria:

• uterine septum
• history of ≥1 miscarriage or infertility;
• desire to have children in the future

Exclusion Criteria:

• pregnancy;
• menopause;
• precancerous state or malignancy of the reproductive organs;
• benign lesions in the myometrium of the uterine fundus (myomas or adenomyosis)
• lesions distorting the uterine cavity (submucosal myomas or intrauterine adhesions) on ultrasonography;
• withdrawal of patient consent;
• rare complex uterine congenital anomalies without an ASRM classification such as uterine septum with double cervix ;
• presence of external intercornual cleft;
• incomplete (internal fundal indentation 10 mm) or non-standardized septum resection (internal fundal indentation ,10 mm and uterine myometrial thickness .10 mm at the fundus), confirmed intraoperatively
• excessive fundal incision (uterine myometrial thickness ,6 mm at the fundus confirmed intraoperatively)