Abnormal uterine bleeding

INTRODUCTION — Under normal circumstances, a woman's uterus sheds a limited amount of blood during each menstrual period. Bleeding that occurs between menstrual periods or excessive bleeding that occurs during menstruation is considered to be abnormal uterine bleeding. Once a woman enters menopause and menstrual cycles have ended, any bleeding, other than the small amounts that can occur in women on hormone replacement therapy, is considered abnormal.

Abnormal uterine bleeding can be caused by many different conditions. A history and physical examination are important first steps in determining the cause.

CAUSES — While most conditions that cause abnormal uterine bleeding can occur at any age, some are more likely to occur at particular times in a woman's life.

Bleeding before menarche — Bleeding before menarche (the first period in a girl's life) is always abnormal and can be caused by trauma, a foreign body (such as toys, coins, or toilet tissue), irritation of the genital area (due to bubble bath, soaps, lotions, or infection), or urinary tract problems. Bleeding can also occur as a result of sexual abuse.

Adolescents — Many girls have episodes of irregular bleeding during the first few years after their periods begin. This usually resolves without treatment when the girl's hormonal cycle and ovulation normalizes. If bleeding persists beyond this time, or if the bleeding is heavy, further evaluation is needed.

Abnormal bleeding in this age group can also be caused by pregnancy, bleeding disorders, some medical illnesses, and infection.

Birth control pills — Girls and women who use oral contraceptives may experience "breakthrough" bleeding between periods. If this occurs during the first months of oral contraceptive use, it may be due to changes in the lining of the uterus. If it persists for more than several months, a different oral contraceptive may be prescribed.

Breakthrough bleeding can also happen if the oral contraceptive is not taken regularly. If this occurs, the breakthrough bleeding may be an indication that the pill is not effective. Additional contraception may be necessary until the oral contraceptives are taken on a regular schedule and the breakthrough bleeding stops. If an adolescent has persistent breakthrough bleeding, further evaluation is needed.

Premenopausal women — Many different conditions can cause abnormal bleeding in women between adolescence and menopause. Abrupt changes in hormone levels at the time of expected ovulation can cause vaginal spotting, or small amounts of bleeding. As noted above, breakthrough bleeding can occur in women who use oral contraceptives.

In women who do not ovulate regularly (anovulatory women), irregular changes in hormone levels can cause bleeding to occur intermittently and in varying amounts. Although anovulation is most common when periods first begin and during perimenopause, it can occur at any time during the reproductive years. (See "Patient information: Menstrual cycle disorders (Absent and irregular periods)").

Among women who ovulate normally, some experience excessive blood loss during their periods or bleed between periods. The most common causes of such bleeding are uterine fibroids or polyps. These irregular growths and benign tumors are composed of uterine tissue that distort the structure of the uterus and lead to abnormal uterine bleeding. Fibroids and polyps can also occur in anovulatory women. (See "Patient information: Fibroids" and see "Patient information: Menorrhagia (Excessive menstrual bleeding)").

Other causes of abnormal uterine bleeding in premenopausal women include: Pregnancy Cancer of the endometrium (lining of the uterus) or benign precancerous endometrial lesions Endometritis or inflammation of the endometrium A pelvic or vaginal infection Clotting disorders such as von Willebrand disease, platelet abnormalities, or problems with clotting factors Some systemic illnesses such as hypothyroidism, liver disease, or chronic renal disease

Perimenopausal women — Before menstruation stops, a woman passes through a period called perimenopause. During perimenopause, normal hormonal cycling begins to change and ovulation may be inconsistent. While estrogen secretion continues, progesterone secretion declines. These hormonal changes can cause the endometrium to grow and produce excess tissue, increasing the chances that polyps or endometrial hyperplasia (thickened lining of the uterus) will develop and potentially cause abnormal bleeding. Women in perimenopause are also at risk for other conditions that cause abnormal bleeding, including cancer, infection, and systemic illnesses. Further evaluation is indicated if a woman experiences persistent irregular menstrual cycles or an episode of profuse bleeding.

Women in perimenopause still ovulate some of the time and can become pregnant; pregnancy can cause abnormal bleeding. In addition, women in perimenopause may use hormonal contraceptive medications, which can cause breakthrough bleeding.

Menopausal women — A number of conditions can cause abnormal bleeding during the menopause. Many women are on hormone replacement therapy at some point during menopause and may experience cyclical bleeding. Any other bleeding that occurs during menopause is abnormal and should be investigated. Causes of abnormal bleeding during menopause include: Atrophy or thinning of the tissue lining the vagina and uterus Cancer of the uterine lining or endometrium Polyps or fibroids Endometrial hyperplasia Infection of the uterus Use of blood thinners or anticoagulants Side effects of radiation therapy

EVALUATION

Initial assessment — While taking a woman's medical history, a clinician will review a number of factors that can help identify the cause of abnormal bleeding. These include: the duration and quantity of the bleeding; factors that seem to bring the bleeding on; symptoms that occur along with the bleeding such as pain, fever, or vaginal odor; the relationship between bleeding and sexual relations; whether there is a personal or family history of bleeding disorders; the woman's medical history and medications she is taking; and whether the woman has experienced a weight change, stress, started a new exercise program, or has any underlying medical problems.

The clinician will perform a general physical exam to evaluate the woman's overall health, and a pelvic examination to confirm that the bleeding is from the uterus and not from another site like the external genitals or the rectum. During the pelvic exam, the clinician will look for any obvious lesions (cuts, sores, or tumors) and will examine the size and shape of the uterus. They will examine the cervix to look for signs of cervical bleeding, and a Pap smear may be obtained to examine the cells of the cervix (the lower end of the uterus, where it opens to the vagina).

In addition to a careful history and physical examination, laboratory tests and diagnostic procedures may be used to identify the cause of abnormal bleeding.

Lab tests — In premenopausal women, a pregnancy test is usually performed. If there is any abnormal vaginal discharge, a culture may be performed. Lab tests may also be conducted to determine whether there are problems with blood clotting or other systemic conditions, such as hypothyroidism, liver disease, or kidney problems.

Tests to determine ovulatory status — Because hormonal irregularities can contribute to abnormal uterine bleeding, blood tests may be performed in premenopausal women to determine whether they ovulate (produce an egg) during each monthly cycle. As an example, a woman may be asked to record when her periods begin and end for several months and to note any premenstrual changes, like cramps or breast tenderness, that occur. Progesterone, which is released at the time of ovulation, may be measured with a blood test.

Endometrial assessment — Tests that assess the endometrium (lining of the uterus) may be performed to rule out endometrial cancer and structural abnormalities such as uterine fibroids or polyps. Such tests include:

Endometrial biopsy — An endometrial biopsy is often performed in women over age 35 to rule out endometrial cancer or unusual endometrial growths. A biopsy may also be performed in women younger than 35 if they have risk factors for endometrial cancer. Risks include obesity, chronic anovulation, history of breast cancer, tamoxifen use or a family history of breast cancer or some other cancers. During the biopsy, a thin instrument is inserted through the vagina into the uterus to obtain a small sample of endometrial tissue. The biopsy can be performed in a healthcare provider's office without anesthesia. Because only a small portion of the endometrium is sampled, the biopsy may miss some causes of bleeding and other tests may be necessary.

Transvaginal ultrasound — An ultrasound uses sound waves to measure an organ's shape and structure. In a transvaginal ultrasound, a small ultrasound probe is inserted into the vagina so that it is closer to the uterus and can provide a cleare image of uterine contents. A transvaginal ultrasound is a minimally invasive way to determine whether abnormal uterine structures, or signs of excessive endometrial growth, are present. However, because it cannot distinguish between different types of structural abnormalities, further testing may be necessary if any are found.

Saline infusion sonography or sonohysterography — In this test, a transvaginal ultrasound is performed after sterile saline is instilled into the uterus. This procedure gives a better picture of the inside of the uterus, and small lesions can be more easily detected. However, because tissue samples cannot be obtained during the procedure, a final diagnosis is not always possible and additional evaluation through hysteroscopy or dilation and curettage (D&C) may be necessary.

Magnetic resonance imaging (MRI) — MRI is non-invasive and uses a magnetic field and radio waves to visualize organs. It is sometimes used to determine the presence of fibroids or other structural abnormalities.

Hysteroscopy — In a hysteroscopy, a small scope is inserted through the cervix and into the uterus. Air or fluid is injected to expand the uterus and to allow the physician to see the inside of the uterus. Tissue samples may be taken. Sedation with regional anesthesia (eg, spinal or epidural) or general anesthesia (medicine given to induce sleep) is used to minimize discomfort during the procedure.

Dilation and curettage (DC) — In a D&C, the cervix or opening of the uterus is dilated, and instruments are inserted and used to remove endometrial or uterine tissue. A D&C usually requires anesthesia. It may be used to more completely sample the tissue inside the uterus. It can sometimes be used as a treatment for prolonged or excessive bleeding that is due to hormonal changes and that is unresponsive to other treatments. (See "Patient information: Dilation and curettage (D&C)").

TREATMENT — The treatment of abnormal bleeding is based upon the underlying cause.

Oral contraceptives — Oral contraceptives are often used to treat uterine bleeding that is due to hormonal changes or hormonal irregularities. Oral contraceptives may be used in women who do not ovulate regularly to establish regular bleeding cycles and prevent excessive growth of the endometrium. In women who do ovulate, they may be used to treat excessive menstrual bleeding. Nonsteroidal anti-inflammatory drugs (NSAIDS, eg ibuprofen, naproxen sodium) may also be helpful in reducing blood loss and cramping in these women.

During perimenopause, oral contraceptives or other hormonal therapy may be used to regulate menstruation and prevent excessive growth of the endometrium. (See "Patient information: Menorrhagia (Excessive menstrual bleeding)").

Intrauterine device — An intrauterine contraceptive device (IUD) that secretes progestin may be recommended for women who do not ovulate regularly. IUDs are devices that are inserted by a healthcare provider into the uterus through the vagina and cervix. Most are made of molded plastic and include an attached plastic string that projects through the cervix, enabling the woman to check that the device remains in place (show picture 1).

Levonorgestrel-releasing IUDs decrease menstrual blood loss by 40 to 50 percent and decrease pain associated with periods. Some women completely stop having menstrual bleeding as a result of the IUD, although this effect is reversible if the IUD is removed. (See "Patient information: Contraception").

Surgery — Surgery may be necessary to remove abnormal uterine structures. Women who have completed childbearing who have heavy menstrual bleeding can consider a surgical procedure such as endometrial ablation. This procedure is done while the woman is under general or regional anesthesia, and uses heat, cold, or a laser to destroy the lining of the uterus.

Women with fibroids can have surgical treatment of their fibroids, either by removing the fibroid(s) (eg, myomectomy) or by reducing the blood supply of the fibroids (eg, uterine artery embolization). (See "Patient information: Fibroids").

Bleeding due to endometrial cancer, systemic diseases such as hypothyroidism or clotting disorders, or infection require treatment of the specific cause.

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem. Because no two patients are exactly alike and recommendations can vary from one person to another, it is important to seek guidance from a provider who is familiar with your individual situation.

This discussion will be updated as needed every four months on our web site (www.patients.uptodate.com). Additional topics as well as selected discussions written for healthcare professionals are also available for those who would like more detailed information.

A number of web sites have information about medical problems and treatments, although it can be difficult to know which sites are reputable. Information provided by the National Institutes of Health, national medical societies and some other well-established organizations are often reliable sources of information, although the frequency with which they are updated is variable. National Library of Medicine

(www.nlm.nih.gov/medlineplus/healthtopics.html)
American Academy of Family Physicians

(www.familydoctor.org)
The Nemours Foundation

(www.kidshealth.org, search for menstrual)
The Hormone Foundation

(www.hormone.org)


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3. Farquhar, CM, Lethaby, A, Sowter, M, et al. An evaluation of risk factors for endometrial hyperplasia in premenopausal women with abnormal menstrual bleeding. Am J Obstet Gynecol 1999; 181:525.
4. Iatrakis, G, Diakakis, I, Kourounis, G, et al. Postmenopausal uterine bleeding. Clin Exp Obstet Gynecol 1997; 24:157.