Threatened Miscarriage

Reviewed on 7/29/2022

What to Know About Threatened Miscarriage

Picture of a pregnant woman holding her belly.
You should contact your doctor if you are pregnant and have vaginal bleeding.

Facts About Threatened Miscarriage

  • Vaginal bleeding is common in early pregnancy. About 1 in 4 pregnant women has some bleeding during the first few months.
  • About half of these women stop bleeding and have a normal pregnancy.
  • Bleeding and pain associated with threatened miscarriage are usually mild. In the best case scenario, the cervical os (mouth of the womb) is closed. (A health care professional can determine if the cervical os is open by performing a pelvic exam.)
  • Typically, no tissue has been passed from the womb. The womb and Fallopian tubes may be tender.
  • When a miscarriage is inevitable, the cervical os is open (dilated).
    • Bleeding is often heavier, and abdominal pain and cramping often occur.
    • If a miscarriage is incomplete, the cervical os is open, and the pregnancy is in the process of being expelled.
    • An ultrasound examination may reveal some material that is remaining in the womb.
    • Bleeding may be heavy and abdominal pain is almost always present.
  • With a complete miscarriage, bleeding and abdominal pain have occurred but have usually subsided.
    • Products of conception have been passed.
    • The early fetus has been passed and was not alive.
    • Ultrasound reveals an empty womb.

What Is a Threatened Miscarriage?

Any bleeding other than spotting during early pregnancy may indicate a threatened miscarriage. (A miscarriage may also be referred to as a spontaneous abortion.)

What Are the Symptoms and Signs of a Threatened Miscarriage?

Symptoms of a spontaneous miscarriage include vaginal bleeding and abdominal pain.

  • Bleeding may be only slight spotting, or it can be heavy. The healthcare professional may ask how heavy the bleeding is, and how many pads are being soaked through per hour. The healthcare professional will also ask about blood clots or tissue passed.
  • Pain and cramping are in the lower abdomen. They may be on one side, both sides, or in the middle. The pain can go into the lower back, buttocks, and genitals.

What Causes a Threatened Miscarriage?

Although the actual cause of the miscarriage is often unclear, the most common causes include the following:

  • An abnormal fetus is almost always the cause of miscarriages during the first 3 months of pregnancy (first trimester). Problems in the chromosomes cause an abnormal fetus and are found in more than half of miscarried fetuses. The risk of defective chromosomes increases with the woman's age.
  • Miscarriage during the months 4-6 of pregnancy (second trimester) is usually related to an abnormality in the mother rather than in the fetus.
    • Chronic disease: Chronic illnesses, including diabetes, severe high blood pressure, kidney disease, lupus, and an underactive or overactive thyroid gland, are frequent causes of a miscarriage. Prenatal care is important because it screens for some of these diseases.
    • Hormones: Inadequate hormone production is an occasional cause of miscarriages.
    • Infections: Acute infections, including German measles, CMV (cytomegalovirus), mycoplasma (atypical pneumonia) and other unusual germs can also cause miscarriage.
    • Reproductive abnormalities: Diseases and abnormalities of the internal female organs can also cause miscarriage. Some examples are an abnormal womb, fibroids, weakness in the mouth of the womb (cervix), abnormal growth of the placenta (also called the afterbirth), and being pregnant with multiples. (e.g. twins or triplets).
    • Other factors: Other factors, especially certain drugs, including excessive caffeine, alcohol, tobacco, and cocaine, may be the cause.

When to Call a Doctor for a Threatened Miscarriage

A pregnant woman who experiences cramping or bleeding at any time should call her healthcare professional.

A pregnant woman who experiences these symptoms but does not have a doctor should go to the closest emergency medical department to be examined.

A pregnant woman should go to the hospital if she experiences the following symptoms:

  • Heavy bleeding (soaking more than one pad per hour)
  • Passing something that looks like tissue (place this tissue in a container and take it with you to the hospital)
  • Severe cramping (like a menstrual period)
  • Cramping or bleeding accompanied by fever
  • Bleeding or abdominal pain in a woman who has had a previous ectopic pregnancy (tubal pregnancy)
  • Vomiting so severe she can't keep anything down

How Is a Threatened Miscarriage Diagnosed?

Medical history

The doctor or nurse in the emergency department will ask many questions, such as the following:

  • How far along is your pregnancy?
  • When was your last normal period?
  • How many times have you been pregnant?
  • How many living children do you have?
  • How many miscarriages have you had?
  • Have you ever had an ectopic (tubal) pregnancy?
  • Were you using any sort of birth control when you got pregnant this time?
  • Have you had any prenatal care?
  • Have you had an ultrasound yet to show that the pregnancy is in the right place?
  • What medical problems do you have?
  • What medications do you take every day?
  • What herbs or other products do you take every day?

Physical exam

For the pelvic exam, the patient will lie on her back with the knees bent and the feet in stirrups.
  • The patient may have a speculum exam. A metal or plastic device is put in your vagina and then opened, spreading the walls of the vagina apart so the healthcare professional can look right at the mouth of your womb. If there is a lot of blood or clots, the healthcare professional may use a clamp or gauze to remove them. The patient should not feel any pain during this part of the exam, although she may be embarrassed and uncomfortable.
  • You may have bleeding from the vagina before, during, and even after a miscarriage. The healthcare professional
    will assess the opening of the entrance to the womb (called the os) and, depending on the findings, may be able to tell you more accurately which of the stages of miscarriage you might be experiencing.
  • The healthcare professional may put gloved fingers in the patient's vagina and feel the abdomen with the other hand. He or she can feel whether the mouth of the woman's uterus is open, how big the uterus may be, and whether there are any signs of infection or tubal pregnancy. The size of the uterus may be smaller than expected for the fetus if the patient has already miscarried.

Lab tests

Pregnancy tests may be run on urine or blood. The healthcare professional or emergency department doctor, if the woman goes to the hospital with alarming symptoms, will act quickly to determine if she is pregnant.

  • A urine pregnancy test along with blood samples will be sent to the laboratory to check for blood loss or anemia, blood type, and the level of the pregnancy hormone. This hormone is called human chorionic gonadotropin or hCG.
    • A number too low may suggest that it is an abnormal pregnancy. No single number is "normal." A very low number (under 1,000) suggests an abnormal pregnancy, although it could just be an early pregnancy.
    • A very high number (over 100,000) strongly suggests a normal living pregnancy. Most other numbers by themselves do not help a lot but can be compared to another test done in 2 to 3 days to see if everything is developing normally.
  • A complete blood count (CBC) may be ordered. If the patient has been bleeding a lot, she may be anemic due to the loss of too much blood.
  • If she has a fever, the white cell count may suggest she has an infection.
  • If the patient does not know her blood type, this will also be checked. If she is Rh-negative, the patient will probably receive a special medicine called RhoGAM to prevent maternal and fetal blood from interacting.
  • If the patient has symptoms of a urinary infection, a urine sample will be taken and examined.


If a woman is pregnant, an ultrasound may be performed to look for evidence of a pregnancy within the uterus. If the radiologist, gynecologist, or emergency department doctor cannot find evidence of a pregnancy within the uterus, the patient will likely be evaluated further for a pregnancy that is outside of the uterus. When the fertilized egg implants in the Fallopian tube, this is called a tubal or ectopic pregnancy.

The technician may put some jelly on the abdomen for transabdominal ultrasound and press down with a probe to see the internal organs. The ultrasound technician may also use a vaginal probe inside the vagina to get a better look at the Fallopian tubes and ovaries. Neither of these studies should be painful.

What Medications Are Available for Pain Relief From a Threatened Miscarriage?

Is There Surgery for a Threatened Miscarriage?

Dilation and curettage (D&C) is a procedure that involves dilating the uterine cervix so that the lining tissue (endometrium) of the uterus can be removed by scraping or suction. D&C is a safe procedure that is done for a variety of reasons. It is minor surgery performed in a hospital or ambulatory surgery center or clinic. A D&C is usually performed as a diagnostic procedure.

A D&C is often planned as treatment when the source of the problem is already known. One situation is an incomplete miscarriage or even full-term delivery when, for some reason, the fetal or placental tissue inside of the uterus has not been completely expelled. If tissue is left behind, excess and potentially life-threatening bleeding can result.

Your healthcare professional will avoid D&C in the following situations, except when absolutely necessary:

  • Pelvic infection: If you have an infection involving the reproductive organs, there is a chance the surgical instruments that will enter the vagina and cervix can carry the bacteria from your vagina or cervix into your uterus. There is also an increased risk of injury to infected tissue. For these reasons, the doctor may prefer to wait until after the infection is cleared up with antibiotics before performing the D&C.
  • Blood clotting disorders: Doctors depend on the body's natural ability to clot to stop bleeding after curettage. Women with certain blood disorders may not be candidates for this surgery.
  • Serious medical problems: Heart and lung disease, for example, can make general, and sometimes local, anesthesia more risky.

What Should You Do After a Miscarriage?

Although rest will not prevent miscarriage, you may feel better if you avoid physical exertion. You should also take the following precautions:

  • Do not douche or insert anything (including tampons) into the vagina.
  • Do not have sex until symptoms have been completely gone for one week.
  • Return to the emergency department in the following cases:
    • Cramping worsens
    • Bleeding worsens (requiring more than one pad per hour)
    • Tissue has passed
    • Fever occurs
    • Anything else alarming
  • Another blood test may be performed in 48 to 72 hours to check the hCG level. The rise or fall of this level is helpful in predicting the status of the pregnancy. If the level is falling, the pregnancy may have ended.
  • A follow-up ultrasound may be performed.

What Is the Prognosis for a Threatened Miscarriage?

More than half of women who bleed during the first 12 weeks of pregnancy will stop bleeding and continue to have a healthy pregnancy.

For the other half of these women, cramping and bleeding worsen and they will eventually miscarry. A woman may not know whether she is going to miscarry when she leaves the emergency department.

How Do you Prevent Threatened Miscarriage?

While there is no way to predict or prevent miscarriage in most cases, certain steps can be taken to improve the chance of a pregnancy continuing to term.

  • Enroll in prenatal care and follow the advice of your healthcare professional
  • Avoid alcohol, cigarettes, and street drugs, especially cocaine.
  • Avoid or reduce caffeine intake.
  • Control high blood pressure and diabetes.
  • Get treatment for infections.

Health Solutions From Our Sponsors

How Much Bleeding Is Normal during Early Pregnancy?

First trimester bleeding is any vaginal bleeding during the first three months of pregnancy. Vaginal bleeding may vary from light spotting to heavy bleeding with clots. Vaginal bleeding is a common problem in early pregnancy, complicating 20% to 30% of all pregnancies.

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Reviewed on 7/29/2022
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Early Pregnancy Loss. Medscape. Updated: Jun 08, 2019.