Congenital anomalies of the uterus are often asymptomatic and therefore unrecognized. They may affect a young woman due to pain at the time of menarche, or a woman's obstetric and/or gynecologic health.
The classification, diagnosis, and clinical manifestations of congenital uterine anomalies will be reviewed here. Treatment of these anomalies and congenital cervical and vaginal abnormalities are discussed separately. (See "Surgical management of congenital uterine anomalies" and "Congenital cervical anomalies and benign cervical lesions" and "Diagnosis and management of congenital anomalies of the vagina".)
A classification system is an attempt to group by symptomatology, treatment, or prognosis. It is through use of standardized nomenclature that physicians can more accurately codify the symptomatology, treatment, and outcome of patients with uterine anomalies. Unfortunately, there is no universally accepted and interpreted classification system for uterine anomalies.
- The American Fertility Society in 1988 produced a standard form for classification of müllerian defects (table 1 and figure 1) . This descriptive form focuses largely on vertical fusion defects and, therefore, on uterine dysgenesis. Associated anomalies in the vagina, cervix, fallopian tubes, and renal system should also be noted.
- Other classification systems have been described, such as the clinical embryological system shown in the table (table 2) .
Overview — The incidence of congenital uterine anomalies is difficult to determine since many women with such anomalies are not diagnosed, especially if they are asymptomatic. Uterine anomalies occur in 2 to 4 percent of fertile women with normal reproductive outcomes [3-9]. In one of the better designed studies, the uteri of 679 women with normal reproductive outcomes were evaluated with laparoscopy or laparotomy prior to tubal ligation, and then by follow-up hysterosalpingogram (HSG) five months after sterilization . The incidence of congenital uterine anomalies was 3.2 percent . The type and frequency of abnormality were septate uteri (90 percent), bicornuate uterus (5 percent), and didelphic uterus (5 percent).