Vaginal bleeding is any expulsion of blood from the vagina. This bleeding may originate from the uterus, vaginal wall, or cervix. Generally, it is either part of a normal menstrual cycle or is caused by hormonal or other problems of the reproductive system, such as abnormal uterine bleeding.

Regular monthly vaginal bleeding during the reproductive years, menstruation, is a normal physiologic process. During the reproductive years, bleeding that is excessively heavy (menorrhagia or heavy menstrual bleeding), occurs between monthly menstrual periods (intermenstrual bleeding), occurs more frequently than every 21 days (abnormal uterine bleeding), occurs too infrequently (oligomenorrhea), or occurs after vaginal intercourse (postcoital bleeding) should be evaluated.

The causes of abnormal vaginal bleeding vary by age, and such bleeding can be a sign of specific medical conditions ranging from hormone imbalances or anovulation to malignancy (cervical cancer, vaginal cancer or uterine cancer). When vaginal bleeding occurs in prepubertal children or in postmenopausal women, it always needs medical attention. However, bleeding may also indicate a pregnancy complication that needs to be medically addressed.

Etiology

The parameters for normal menstruation have been defined as a result of an international process designed to simplify terminologies and definitions for abnormalities of menstrual bleeding. The causes of abnormal vaginal bleeding vary by age.

Vaginal bleeding in the first week of life after birth is a common observation, and pediatricians typically discuss this with new mothers at the time of hospital discharge. During childhood, one of the most common causes of vaginal bleeding is presence of a foreign body in the vagina which may be caused by normal self-exploration or can be indicative of sexual abuse. This is often associated with pelvic pain, foul discharge, or recurrent genitourinary infections.

Genitourinary injury is also a common cause, and is often the most common cause of hospitalization or emergency department visits for prepubertal vaginal bleeding, comprising up to 45% of such cases.

Premenopausal

Background

In premenopausal women, bleeding can be from the uterus, from vulvar or vaginal lesions, or from the cervix. A gynecologic examination can be performed to determine the source of bleeding. Bleeding may also occur as a result of a pregnancy complication, such as a spontaneous abortion (miscarriage), ectopic pregnancy, or abnormal growth of the placenta, even if the woman is not aware of the pregnancy. This acronym stands for Polyp, Adenomyosis, Leiomyoma, Malignancy and Hyperplasia, Coagulopathy, Ovulatory Disorders, Endometrial Disorders, Iatrogenic Causes, and Not Classified. The FIGO Menstrual Disorders Group, with input from international experts, recommended a simplified description of abnormal bleeding that discarded imprecise terms such as menorrhagia, metrorrhagia, hypermenorrhea, and dysfunctional uterine bleeding (DUB) in favor of plain English descriptions of bleeding that describe the vaginal bleeding in terms of cycle regularity, frequency, duration, and volume.

The PALM causes are related to uterine structural, anatomic, and histolopathologic causes that can be assessed with imaging techniques such as ultrasound or biopsy to view the histology of a lesion. The COEIN causes of abnormal bleeding are not related to structural causes.

  • Leiomyoma (fibroids): Uterine leiomyoma, commonly termed uterine fibroids, are common, and most fibroids are asymptomatic. Von Willebrand disease is the most common coagulopathy, and most women with von Willebrand disease have heavy menstrual bleeding. Heavy menstrual bleeding since menarche is a common symptom for women with bleeding disorders, and in retrospective studies, bleeding disorders have been found in up to 62% of adolescents with heavy menstrual bleeding.
  • Ovulatory dysfunction: Ovulatory dysfunction or anovulation is a common cause of abnormal bleeding that may lead to irregular and unpredictable bleeding, as well as variations in the amount of flow including heavy bleeding. Endocrine, or hormonal, causes of ovulatory disorders include polycystic ovary syndrome (PCOS), thyroid disorders, hyperprolactinemia, obesity, eating disorders including anorexia nervosa or bulimia, or to an imbalance between exercise and caloric intake.
  • Endometrial: Endometrial causes of abnormal bleeding include infection of the endometrium, endometritis, which may occur after a miscarriage (spontaneous abortion) or a delivery, or may be related to a sexually-transmitted infection of the uterus, fallopian tubes or pelvis generally termed pelvic inflammatory disease (PID). Other endometrial causes of abnormal bleeding may relate to the ways that the endometrium heals itself or develops blood vessels. The risk of breakthrough bleeding with oral contraceptives is greater if pills are missed.
  • Not classified: The Not Classified category of the PALM-COEIN system includes conditions that may be rare, or whose contribution to abnormal bleeding has not been well established or understood. Of these, half go on to miscarry and half bring the fetus to term. There are a number of causes including complications to the placenta, such as placental abruption and placenta previa. Other causes include miscarriage, ectopic pregnancy, molar pregnancy, incompetent cervix, uterine rupture, and preterm labor. Bleeding in early pregnancy may be a sign of a threatened or incomplete miscarriage. In the second or third trimester a placenta previa (a placenta partially or completely overlying the cervix) may bleed quite severely. Placental abruption is often associated with uterine bleeding as well as uterine pain.

Vaginal bleeding during pregnancy can be normal, especially in early pregnancy. Light spotting early on in pregnancy can be a result of the fertilized egg implanting into the uterus. Additionally, during pregnancy, the blood supply to the cervix increases, which can cause the cervix to be more friable and bleed more easily than a non-pregnant woman's cervix. Because of this, some light spotting after intercourse can be normal. However, bleeding may also indicate a pregnancy complication that needs to be medically addressed and any vaginal bleeding during pregnancy should prompt a call to the patient's obstetric provider.

Perimenopausal

While many of the causes of premenopausal bleeding still apply to perimenopausal women, there is an additional cause of abnormal uterine bleeding in this category of women, which is the hormonal changes. Around age 40, women's hormones begin to change and this can cause variation in menstrual patterns. This can last for years, with menstrual periods lasting various lengths and coming at various intervals. Menopause is considered complete after a woman has gone 12 months without a menstrual period.

Postmenopausal

Endometrial atrophy, uterine fibroids, and endometrial cancer are common causes of postmenopausal vaginal bleeding. About 10% of cases are due to endometrial cancer. Uterine fibroids are benign tumors made of muscle cells and other tissues located in and around the wall of the uterus. Women with fibroids do not always have symptoms, but some experience vaginal bleeding between periods, pain during sex, and lower back pain. <!--This article has a delayed release (embargo) and will be available in PMC on August 6, 2019-->

Diagnostic evaluation

The cause of the bleeding can often be discerned on the basis of the bleeding history, physical examination, and other medical tests as appropriate. The physical examination for evaluating vaginal bleeding typically includes visualization of the cervix with a speculum, a bimanual exam, and a rectovaginal exam. These are focused on finding the source of the bleeding and looking for any abnormalities that could cause bleeding. In addition, the abdomen is examined and palpated to ascertain if the bleeding is abdominal in origin. Typically a pregnancy test is performed as well. If bleeding was excessive or prolonged, a CBC may be useful to check for anemia. Abnormal endometrium may have to be investigated by a hysteroscopy with a biopsy or a dilation and curettage.

In 2011, the International Federation of Gynaecology and Obstetrics (FIGO) recognized two systems designed to aid research, education, and clinical care of women with abnormal uterine bleeding (AUB) in the reproductive years. Endometrial sampling is indicated if having the following findings and/or symptoms:thumb|FIGO System 1. The system for definition and nomenclature of normal and abnormal uterine bleeding (AUB) in the reproductive years.

Complications

Severe acute bleeding, such as caused by ectopic pregnancy and post-partum hemorrhage, leads to hypovolemia (the depletion of blood from the circulation), progressing to shock. This is a medical emergency and requires hospital attendance and intravenous fluids, usually followed by blood transfusion. Once the circulating volume has been restored, investigations are performed to identify the source of bleeding and address it. Eliminating the cause will resolve the anemia, although some women require iron supplements or blood transfusions to improve the anemia. Long-term treatments include hormonal IUD insertion, birth control pills, progestin pills or progestin shots (Depo-Provera), and NSAIDs such as ibuprofen