Chapter 2 ABNORMAL PREMENOPAUSAL UTERINE BLEEDING

In women of childbearing age, abnormal uterine bleeding includes any change in menstrual period frequency, duration, or amount of flow, as well as bleeding between cycles. A menstrual cycle of fewer than 21 days or more than 35 days is considered abnormal. Likewise, a menstrual flow of fewer than 2 days or more than 7 days is abnormal.

When abnormal uterine bleeding is evaluated (Figs. 2-1 and 2-2), it is important to make certain that the bleeding is not from a gastrointestinal or urinary source. Once it is clear that the bleeding is vaginal, pregnancy should be the first consideration in women of childbearing age. After pregnancy has been ruled out, iatrogenic causes of abnormal uterine bleeding should be considered. Medications linked to abnormal premenopausal uterine bleeding are outlined later in this chapter. After pregnancy and iatrogenic causes have been excluded, systemic conditions should be considered. These systemic causes and the suggested workup, outlined later in the chapter, include thyroid, hematologic, pituitary, hepatic, adrenal, and hypothalamic disorders.

Figure 2-1. Abnormal uterine bleeding in women of childbearing age. Sequential steps through the differential diagnosis of abnormal uterine bleeding in women of childbearing age.

Figure 2-2. Presumed dysfunctional uterine bleeding in women of childbearing age: evaluation based on risk factors for endometrial cancer.^*†‡

Genital tract disease should be considered. Diagnoses that should be considered include cervical pathologic processes, sexually transmitted disease, trauma, uterine fibroids, endometrial polyps, endometrial hyperplasia and atypia, and endometrial cancer.

Dysfunctional uterine bleeding occurs during the childbearing years, but the diagnosis is one of exclusion that should be made only after pregnancy, iatrogenic causes, systemic conditions, and obvious genital tract disease have been ruled out.

Further evaluation of abnormal uterine bleeding depends on the patient’s age and the presence of risk factors for endometrial cancer. These risk factors include anovulatory cycles, obesity, nulliparity, age greater than 35 years, and tamoxifen therapy. Anovulation occurs at the extremes of reproductive age (during the postmenarchal and perimenopausal periods).

Because endometrial cancer is rare in 15- to 18-year-old girls, dysfunctional uterine bleeding in most adolescents can be treated safely with hormone therapy and observation, without the need for diagnostic testing.

Of cases of endometrial carcinoma, 20% to 25% occur before menopause, and the risk of developing endometrial cancer increases with age. Thus, the American College of Obstetricians and Gynecologists recommends endometrial evaluation in women aged 35 and older who have abnormal uterine bleeding. Endometrial evaluation is also recommended for patients younger than 35 who are at high risk for endometrial cancer. Women with vaginal bleeding who are younger than 35 years and have no identifiable risk factors for neoplasia can be assumed to have dysfunctional bleeding and treated accordingly. However, if bleeding continues in a patient at low risk for neoplasia despite medical management, endometrial evaluation is indicated.

Endometrial evaluation may be accomplished by endometrial biopsy, transvaginal ultrasonography, saline-infusion sonohysterography, dilatation and curettage, or hysteroscopy with biopsy. Endometrial evaluation usually proceeds with endometrial biopsy, which can be performed in the office using the Pipelle technique. The efficacy of transvaginal ultrasonography in the premenopausal population is not as well defined as it is in postmenopausal women. For this reason, endometrial evaluation usually begins with endometrial biopsy. However, because endometrial biopsy may miss a significant percentage of benign endometrial lesions such as polyps and fibroids, some clinicians recommend proceeding to saline-infusion sonohysterography or dilatation and curettage with hysteroscopy.