Uterine Agenesis

Introduction

• Description: Uterine agenesis is the failure of the Müllerian system to fuse in the midline to form the uterus. Incomplete variations of this failure result in a didelphic, bicornuate, septate, or arcuate uterus. It is also known as Mayer–Rokitansky–Küster–Hauser syndrome (MRKH).

• Prevalence: 1/4000–5000 female births. Second most common (15%) cause of primary amenorrhea but only 3% of uterine anomalies.

• Predominant Age: Congenital. Diagnosed when the patient fails to menstruate at puberty.

• Genetics: Isolated developmental defect except for androgen insensitivity syndrome.

Etiology and Pathogenesis

• Causes: Isolated developmental defect in most patients, production of antimüllerian hormone by Sertoli cells in fetal testes (in androgen resistance syndrome). 17α-Hydroxylase deficiency, 17, 20-desmolase deficiency, and agonadism may account for those rare individuals with no breast or uterine development and a male karyotype (vanishing testes syndrome). Müllerian agenesis (MRKH syndrome) is a congenital malformation characterized by a failure of the Müllerian ducts to develop, resulting in a missing uterus and variable malformations of the vagina. Development of the upper tract occurs independent of the ovaries, so these women have normal ovarian function. Unlike other intersex conditions, MRKH is not associated with virilization but only absence of upper genital tract structures.

• Risk Factors: None known.

Signs and Symptoms

• Primary amenorrhea (accounts for 15% of primary amenorrhea, second most common cause)

• Shortened or absent vagina (difficult or painful intercourse)

• Breast development may be absent in some syndromes but most often present and normal

• Pelvic examination demonstrates complete or partial absence of the cervix, uterus, and vagina

• Those with rudimentary uterine elements may experience cyclic abdominal pain with a growing pelvic mass (hematometra).

Diagnostic Approach