ENLmedical.com: Conditions And Concerns: Medical Encyclopedia: Abortion, inevitable

Abortion, threatened

Causes and Risks:
Approximately 20% of pregnant women experience some vaginal bleeding, with or without abdominal cramping , during the first trimester of pregnancy. This is known as a threatened abortion. However, most of these pregnancies go on to term with or without treatment. Spontaneous abortion occurs in less than 30% of the women who experience vaginal bleeding during pregnancy .

In the cases that result in spontaneous abortion, the usual cause is fetal death . Such death is typically the result of a chromosomal or developmental abnormality. Other potential causes include infection, maternal anatomic defects, endocrine factors, immunologic factors, and maternal systemic disease. Estimates report that up to 50% of all fertilized eggs abort spontaneously, usually before the woman knows she is pregnant. Among known pregnancies, the rate of spontaneous abortion is approximately 10%. These usually occur between 7 and 12 weeks of gestation. Increased risk is associated with a maternal age of more than 35 years, maternal systemic disease (such as diabetes or thyroid dysfunction ), and a history of three or more prior spontaneous abortions.

Prevention:
Early and comprehensive prenatal care decreases risk. It is preferable to detect and treat known maternal disorders before conception occurs. Avoiding environmental hazards such as X-rays and infectious diseases also decreases the risk of miscarriage in early pregnancy .

Spontaneous abortion is not preventable if there is fetal death. In fact, it is important for the uterus to expel all products of conception in such cases. A missed abortion occurs when a dead fetus is not expelled from the uterus. When only part of the dead fetus is expelled, it is an incomplete abortion .

Symptoms:

Vaginal bleeding during the first 20 weeks of pregnancy (last menstrual period was less than 20 weeks ago).
Abdominal cramps may or may not accompany vaginal bleeding .

Note: With true miscarriage , low back pain or abdominal pain (dull to sharp, constant to intermittent) typically occurs and tissue or clot-like material may pass from the vagina .

Signs and Tests:
Pelvic examination should reveal a cervix that is neither thinned (effaced) nor open (dilated). The presence of effacement and/or dilation is consistent with impending miscarriage .

A serum HCG may be performed to confirm that a pregnancy exists.
An HCG (quantitative) test may be repeated over a period of days or weeks to confirm either continued pregnancy or fetal death.
A CBC may be obtained to determine the degree of blood loss .
A WBC with differential may be obtained to rule out infection.
A pregnancy ultrasound is used to detect fetal movement and/or a heartbeat.

This condition may also alter the results of the following tests:

Treatment:
Activity restrictions vary, from avoiding some forms of exercise to complete bedrest. Restricting activity will not guarantee that a miscarriage will not occur. Providers typically recommend abstaining from intercourse until symptoms resolve. The woman's condition should be monitored carefully. Mild sedatives such as flurazepam may be prescribed.

The use of progesterone is controversial. The potential benefit is the relaxation of smooth muscle , including the muscles of the uterus. However, this may increase the potential risk of an incomplete abortion or an abnormal pregnancy . It also increases the risk of retaining a hydatidiform mole . In the absence of a luteal phase defect, progesterone supplementation should not be used.

Prognosis:
The probable outcome is good if the pregnancy continues to progress and all the symptoms disappear.

Complications:

Spontaneous abortion .
Moderate to heavy blood loss .
Anemia .
Dead fetus syndrome.
Infection.

Call Your Healthcare Provider:
It is imperative for a woman who knows she is (or is likely to be) pregnant and who has any signs or symptoms of threatened abortion to contact her prenatal provider immediately.