Uterine septum: a guideline

•Septate uterus configurations include partial septum, and complete septum in association with cervical septum or duplicated cervix.•There is no uniform definition of septate configurations.•Most women with a septate uterus have efficient reproductive function.•Arcuate uterus, although developmentally considered part of the spectrum of resorption failure, is considered a normal variant and should be differentiated from septate uterus for purposes of prognosis and surgical management.•There is fair evidence that 3-D ultrasound, sonohysterography, and MRI are good diagnostic tests for distinguishing a septate and bicornuate uterus when compared with laparoscopy/hysteroscopy. (Grade B)•The data regarding reproductive implications of septate uteri and treatment effects are limited and comprised primarily of observational, principally descriptive studies without untreated control groups.•There is insufficient evidence to conclude that a uterine septum is associated with infertility. (Grade C)•Several observational studies indicate that hysteroscopic septum incision is associated with improved clinical pregnancy rates in women with infertility. (Grade C)•There is fair evidence that a uterine septum contributes to miscarriage and preterm birth. (Grade B)•Some evidence suggests that a uterine septum may increase the risk of other adverse pregnancy outcomes such as malpresentation, intrauterine growth restriction, placental abruption, and perinatal mortality. (Grade B)•Some limited studies indicate that hysteroscopic septum incision is associated with a reduction in subsequent miscarriage rates and improvement in live-birth rates in patients with a history of recurrent pregnancy loss. (Grade C)•Some limited studies indicate that hysteroscopic septum incision is associated with an improvement in live-birth rate in women with infertility or prior pregnancy loss. (Grade C)•There is insufficient evidence to conclude that obstetric outcomes are different when comparing the size as defined by length or width of uterine septa. (Grade C)•Commonly used techniques to resect uterine septum include incision or removal of the septum utilizing cold scissors, unipolar or bipolar cautery, or laser.•Use of distending media for the uterus is dependent on the incision technique or energy source and includes CO2, saline, glycine, sorbitol, or mannitol.•There is insufficient evidence to recommend a specific method for hysteroscopic septum incision. (Grade C)•Although the available evidence suggests that the uterine cavity is healed by 2 months postoperatively, there is insufficient evidence to advocate a specific length.•There is insufficient evidence for or against recommending danazol or GnRH agonists to thin the endometrium prior to hysteroscopic septum incision. (Grade C)•There is insufficient evidence to recommend for or against adhesion prevention treatment, or any specific method following hysteroscopic septum incision. (Grade C)