Abortion

(Interruption of Pregnancy)

ByFrances E. Casey, MD, MPH, Virginia Commonwealth University Medical Center
Reviewed/Revised Aug 2023
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Induced abortion is the intentional ending of a pregnancy by surgery or medications.

  • A pregnancy may be ended by surgically removing the contents of the uterus or by taking certain medications.

  • Complications are uncommon when an abortion is done by a trained health care professional in a hospital or clinic.

  • Induced abortion does not increase risks for the fetus or woman during subsequent pregnancies.

In the United States, about 50% of pregnancies are unintended. About 40% of unintended pregnancies end in induced abortion; 90% of abortions are done during the 1st trimester. States may set restrictions (such as mandatory waiting periods, number of weeks of pregnancy, or notarized consent for minors). These restrictions may delay or prevent access to abortion.

In countries where abortion is legal, complications are rare. Worldwide, about 13% of deaths in pregnant women are due to unsafe abortion. Most of these deaths occur in countries where abortion is highly restricted or illegal.

Pregnancy is confirmed before an abortion is started. Often, ultrasonography is used to estimate the age of the fetus, but sometimes a health care professional's evaluation can estimate the age during the 1st trimester. If women have risk factors for problems related to an abortion (such as heart or lung disease, seizures, or a history of cesarean deliveries), they may require further evaluation.

Contraception can be started immediately after an abortion done before 28 weeks of pregnancy.

Methods of Abortion

Abortion methods include

  • Surgical abortion (surgical evacuation): Removal of the contents of the uterus through the cervix

  • Medications to cause (induce) abortion: Use of medications to stimulate contractions of the uterus, which expel the contents of the uterus

The method used depends in part on how long a woman has been pregnant. Ultrasonography is usually done to estimate the length of the pregnancy. Surgical abortion can be used for most pregnancies up to 24 weeks. Medication abortion can be used for pregnancies that are less than 11 weeks or that are more than 15 weeks.

For abortions done early in the pregnancy, only a local anesthetic may be needed. Conscious sedation (medications that relieve pain and help women relax but allow women to remain conscious) may also be used. Rarely, a general anesthetic is needed.

Before a surgical abortion, women are given antibiotics that are effective against infections in the reproductive tract.

After any abortion (surgical or medication), women with Rh-negative blood are given injection of Rh antibodies called Rho(D) immune globulin. If the fetus has Rh-positive blood, a woman who has Rh-negative blood may produce antibodies to the Rh factor. These antibodies can destroy the fetus's red blood cells. Treatment with Rho(D) immune globulin reduces the risk that the woman's immune system will make these antibodies and endanger subsequent pregnancies. Treatment with immune globulin may be optional before 8 weeks of pregnancy.

Surgical abortion

The contents of the uterus are removed through the vagina. Different techniques are used depending on the length of the pregnancy. They include

Dilationprostaglandin) can also be used to dilate the cervix.

For pregnancies between 14 and 24 weeks long, dilation and evacuation (D and E) is usually used. After the cervix is dilated, suction and forceps are used to remove the fetus and placenta. A sharp curet may be used gently to make sure all products of conception have been removed.

If women wish to prevent future pregnancies, contraception, including a copperintrauterine device (IUD), can be started as soon as the abortion is completed.

Medication abortion

Medication abortions can be used for pregnancies of less than 11 weeks or more than 15 weeks. For an abortion during early pregnancy (less than 11 weeks), the abortion process can be completed at home. For an abortion later in pregnancy, the woman typically is admitted to the hospital to take the medications that will induce labor.

In the United States from 2014 to 2017, medication abortion accounted for 53% of abortions done for pregnancies of less than 11 weeks.

taken by mouth, blocks the action of the hormone progesterone

Clinicians confirm the completion of the abortion by one of the following:

  • Ultrasonography

  • A urine test to measure human chorionic gonadotropin (hCG) on the day the medication is given and 1 week later (hCG is produced early in pregnancy)

  • After a medication abortion, a urine pregnancy test 5 weeks

Prostaglandins

  • 95% of pregnancies that have lasted 8 to 9 weeks

  • 87 to 92% of pregnancies that have lasted 9 to 11 weeks

If a medication abortion is unsuccessful, a surgical abortion may be required.

Complications of Abortion

Complications from abortion are rare when it is done by a trained health care professional in a hospital or clinic. Also, complications occur much less often after an abortion than after delivery of a full-term baby. Serious complications occur in fewer than 1% of women who have an abortion. Death after an abortion is very rare. About 6 out of a million women who have an abortion die, compared with about 140 out of a million women who deliver a full-term baby.

The older the fetus is, the higher the number of complications.

The risk of complications is related to the method used.

  • Surgical evacuation: Complications are rare when surgical abortions are done by health care professionals. The uterus is torn (perforated) by a surgical instrument in fewer than 1 of 1,000 abortions. Injury of the intestine or another organ is even rarer. Severe bleeding during or immediately after the procedure occurs in 6 of 10,000 abortions. Very rarely, the procedure or a subsequent infection causes scar tissue to form in the lining of the uterus, resulting in sterility. This disorder is called Asherman syndrome.

  • Medications:

  • Either method: Bleeding and infection can occur if part of the placenta is left in the uterus. If bleeding occurs or if infection is suspected, clinicians use ultrasonography to determine whether part of the placenta remains in the uterus.

Did You Know...

  • Complications from abortion are rare when it is done by a trained health care professional in a hospital or clinic.

Later, particularly if the woman is inactive, blood clots may develop in the legs.

If the fetus has Rh-positive blood, a woman who has Rh-negative blood may produce Rh antibodies—as in any pregnancy, miscarriage, or delivery. Such antibodies may endanger subsequent pregnancies. Giving the woman injections of Rho(D) immune globulin prevents antibodies from developing. Immune globulin may be optional for pregnancies lasting less than 8 weeks.

Psychologic problems after an abortion are more likely if the following are present

  • Psychologic symptoms before pregnancy

  • Limited social support or a sense of disapproval from their support system

Drugs Mentioned In This Article
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