What Are Abortion and Miscarriage?

What Is Abortion versus Miscarriage?

Abortion refers to the termination of a pregnancy, which may happen naturally or with medical intervention. A miscarriage is known as a
Abortion refers to the termination of a pregnancy, which may happen naturally or with medical intervention. A miscarriage is known as a "spontaneous abortion."

Abortion is a term that refers to the termination of a pregnancy. This can occur with medical intervention such as medications or surgical procedures or it can occur on its own. 

A miscarriage is called a spontaneous abortion, and refers to a pregnancy loss before the 20th week of gestation or the expulsion an embryo or fetus weighing 500 g or less. Miscarriage at this stage occurs in about 31% of pregnancies.

What Are Symptoms of Miscarriage?

Some women may have no symptoms of miscarriage and it is discovered on a routine ultrasound in early pregnancy.

When symptoms of miscarriage occur, they may include:

If you are pregnant and have any signs of a miscarriage, see your doctor right away.

What Causes Miscarriage?

Causes of miscarriage include:

  • Chromosomal abnormalities
    • Present in up to 70% of pregnancy losses before 20 weeks
  • Maternal anatomical abnormalities
  • Trauma
    • Penetrating injuries
    • Gunshot wounds
    • Intimate partner violence

Risk factors for miscarriage include:

  • Increasing maternal age, over 35 years
  • Medical conditions
  • Medication and/or substance use
  • Environmental exposures
    • Ionizing radiation
    • Lead or arsenic exposure
    • Air pollution
  • Race and ethnicity
    • Women of color have an increased risk of miscarriage compared to white women 

How Is Miscarriage Diagnosed?

Once a pregnancy has been diagnosed, a miscarriage may be diagnosed by a doctor with:

  • Pelvic exam
  • Ultrasound
  • Blood tests
  • Tests on tissue you may have passed to confirm a miscarriage
  • Chromosomal tests if you have had previous miscarriages to determine if your chromosomes or your partner’s chromosomes play a role

What Is the Treatment for Miscarriage?

If an ultrasound confirms a miscarriage and determines the embryo is no longer viable or has not fully formed, there are several treatment options:

  • Expectant management
    • Let the miscarriage progress naturally and allow the embryo to pass on its own
    • This may take up to 4 weeks and can be difficult emotionally
    • If the embryo does not pass on its own within 4 weeks, medical or surgical intervention is recommended because of the risk of infections, potential for loss of the uterus, or threat to the mother’s life
  • Medical treatment
    • Medications can be given to help the body expel the pregnancy tissue
    • For most women, these medications work within 24 hours
  • Surgical treatment
    • Suction dilation and curettage (D&C) is a procedure in which the cervix is dilated and tissue from the inside of the uterus is removed
    • If miscarriage occurs with heavy bleeding or signs of infection, surgical treatment is recommended