Uterine bleeding may occur in the absence of current or recent pregnancy, during pregnancy, or in the postpartum period.1 Abnormal uterine bleeding (AUB) is a term that defines menstrual bleeding that occurs on an abnormal schedule, for an abnormal duration of time, or with an abnormal quantity of blood loss.2-6 The term dysfunctional uterine bleeding is no longer used.7,8 Dysfunctional uterine bleeding is a general term that was used to describe irregular bleeding in the nonpregnant patient. AUB can manifest as heavy menstrual bleeding (HMB). HMB is cyclical or ovulatory bleeding and was previously termed menorrhagia. Intermenstrual bleeding (IMB) refers to bleeding that occurs between menses. This was previously termed metrorrhagia. IMB often has a cervical etiology. Approximately 3% of women have physiologic IMB associated with ovulation.9 Approximately 66% of women who have had one or more cesarean births have a defect in the uterus. This is reported as regular postmenstrual spotting.10 Irregular AUB is caused by ovulatory dysfunction (AUB-O) and is often reported as no cycle for 2 to 3 months. When cycles occur, they are often heavy.
A normal menstrual cycle frequency is 21 to 35 days with a duration of 5 to 7 bleeding days. The International Federation of Gynecology and Obstetrics (FIGO) created the PALM-COEIN classification system in 2011 to help categorize bleeding abnormalities based on the underlying etiology and the bleeding pattern.11,12 The acronym divides the causes into structural (PALM) and nonstructural (COIEN). The most common causes of AUB in women of reproductive age include uterine pathology or the “PALM” portion of the classification system.
This chapter will focus on nonpregnant reproductive-age women. Postpartum uterine bleeding or postpartum hemorrhage is discussed in Chapter 166. Perimenopausal bleeding is generally secondary to hormonal imbalances. Postmenopausal bleeding is a concern for benign etiologies (e.g., fibroids) and malignant etiologies (e.g., cancers). Postmenopausal bleeding is considered cancer until proven otherwise. An endometrial biopsy and transvaginal ultrasound (US) should be performed if a uterine source for bleeding is suspected in a postmenopausal woman. Lower genital tract atrophy is the most common benign cause of postmenopausal bleeding and is easily treated with estrogen cream. All postmenopausal bleeding requires follow-up with a Gynecologist.
The most important interventions in AUB are to obtain hemostasis and provide volume repletion if needed (e.g., intravenous fluids or blood products). It is essential to determine if the bleeding is occurring in the presence or absence of a pregnancy, the source of the bleeding, and the most appropriate method for hemostasis.
Acute and more conservative management measures (e.g., conjugated equine estrogen, oral contraceptives, medroxyprogesterone acetate, minor surgical interventions, and tranexamic acid) are warranted when uterine bleeding occurs in a stable patient (Figure 161-1). Stabilization with more invasive measures is warranted when hypovolemia and hemodynamic instability exist (Figure 161-1).