Embryological–clinical classification of female genital tract malformations – a review and update

Based on updated knowledge on genitourinary embryology and after analysing published cases of female urogenital malformations, including those deemed unclassifiable, the authors reviewed and updated their embryological-clinical classification of female genital tract malformations to include all cases with genital or genitourinary malformations. This classification includes: Class 1, abnormalities of the intermediate mesoderm, such as unilateral genitourinary agenesis or hypoplasia, and multiple mesodermal abnormalities; Class 2, mesonephric or Wolffian anomalies, including unilateral renal agenesis and ipsilateral blind or atretic hemivagina syndrome; Class 3, Müllerian anomalies affecting the Müllerian ducts (tubal and common uterine anomalies), the Müllerian tubercle, or the Müllerian tubercle and ducts; Class 4, dysfunctions of the gubernaculum; Class 5, abnormalities of the urogenital sinus and cloaca; and Class 6, malformative combinations. The reproductive outcomes of a given uterine malformation are not the same if that malformation is a consequence of a Wolffian or purely Müllerian anomaly. Additionally, certain malformations often receive inappropriate or inadequate surgery, resulting in persistent problems such as chronic pelvic pain or loss of reproductive function, especially if the anomaly is complex. Updating the embryological-clinical classification will enable all cases with female genital or genitourinary malformation, including those not considered in other classification systems and those previously designated as unclassifiable, to be catalogued and managed.