Curettage, especially postpartum
Secondary to infections
Any transverse blockage of the m¨ullerian system will cause amenorrhea (59). Such outﬂow obstructions include imperforate hymen, transverse vaginal septum, and absence of the cervix or vagina. Transverse blockage of the outﬂow tract with an intact endometrium frequently causes cyclic pain without menstrual bleeding in adolescents. The blockage of blood ﬂow can cause hematocolpos, hematometra, or hemoperitoneum, and endometriosis.
Mayer-Rokitansky-K¨uster-Hauser syndrome includes vaginal agenesis with variable m¨ullerian duct abnormalities accompanied in some cases by renal, skeletal, and auditory abnormalities (60). M¨ullerian agenesis accounts for approximately 10% of cases of primary amenorrhea (2). Of the patients with this syndrome, 15% have an absent, pelvic, or horseshoe kidney, 40% have a double urinary collecting system, and 5% to 12% have skeletal abnormalities(61–63).Mayer-Rokitansky-K¨uster-Hausersyndrome isassociated with abnormal galactose metabolism (64).
Absence of Functioning Endometrium
Amenorrhea may occur if there is no functioning endometrium. When the findings of the physical examination are normal, anatomic abnormalities of the uterine cavity should be considered. A congenitally absent endometrium is a rare finding in patients with primary amenorrhea.
Asherman syndrome, which is more common with secondary amenorrhea or hypomenorrhea, may occur in patients with risk factors for endometrial or cervical scarring (Fig. 30.3). Such risk factors include a history of uterine or cervical surgery, infections related to use of an intrauterine device, and severe pelvic inﬂammatory disease. Asherman syndrome is found in 39% of patients undergoing hysterosalpingography who previously underwent postpartum curettage (65). Infections such as tuberculosis and schistosomiasis may cause Asherman syndrome but are not common for women who have lived their whole lives in the United States. Cervical stenosis resulting from surgical removal of dysplasia (cone biopsy, loop electroexcision procedure) may lead to amenorrhea.
Androgen Insensitivity Phenotypic females with complete congenital androgen insensitivity (previously called testicular feminization) develop secondary sexual characteristics but do not have menses (Fig. 30.2). Genotypically, they are male (XY) but have a defect that prevents normal androgen receptor function, leading to the development of the female phenotype. Serum testosterone is in the normal male range. The vagina may be absent or short.