Threatened Miscarriage - Bleeding In the First 20 Weeks

This Common Pregnancy Complication Usually Does Not Progress to Miscarriage

Female doctor examining pregnant woman, mid section, close-up
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A threatened miscarriage is when a pregnant woman has vaginal bleeding before week 20, but has other indicators of a healthy pregnancy. Threatened miscarriage is a common complication of early pregnancy and does not mean that a miscarriage is inevitable.

Some doctors refer to threatened miscarriage as a threatened abortion or threatened spontaneous abortion. This is different from a medical or surgical abortion.

What Is a Threatened Miscarriage?

A threatened miscarriage is diagnosed when an expectant mother is experiencing vaginal bleeding or spotting, with or without cramping, but the doctor has determined that the cervix is closed and that the baby has a heartbeat. Threatened miscarriage can lead to pregnancy loss, but it usually does not. The statistics differ widely on how many threatened miscarriages lead to miscarriage.

What Causes It?

The causes of threatened miscarriage are largely unknown. Some doctors believe that bleeding in the first trimester can be a sign of an underlying problem with the placenta. If you experience a threatened miscarriage, it's unlikely that it's your fault. The same is true if your threatened miscarriage turns into a miscarriage - it's not because of something you did wrong.

Other Possible Outcomes

Although many women with threatened miscarriages go on to have healthy pregnancies and babies, some women experience more problems.

In 2011, Scottish researchers looked at 14 studies of women who experienced first-trimester bleeding with normal ultrasounds or pregnancies that continued. Based on this research, they concluded that women who have a threatened miscarriage may be more likely to have problems later in their pregnancy, although they stated that these risks are still low.

The authors wrote: "In conclusion, the current meta-analysis reports that women with first-trimester threatened miscarriage are at increased risk of adverse maternal and perinatal outcome, although in the majority of women the risks are low."

Problems the mothers may experience:

  • pregnancy-induced hypertension or preeclampsia - high blood pressure conditions in pregnancy

  • eclampsia - seizures related to preeclampsia

  • antepartum haemorrhage - bleeding in the second half of pregnancy but before labor

  • preterm prelabor rupture of membranes - early rupture of membranes

  • placental abruption - separation of the placenta from the uterus

Problems the babies may experience:

  • preterm delivery
  • intrauterine growth restriction - poor growth of the baby in the womb
  • low birthweight

  • perinatal mortality - stillbirth or early infant death

  • perinatal morbidity - low Apgar score or admission to the neonatal unit

  • congenital malformations - birth defects

How is a Threatened Miscarriage Diagnosed?

If you're experiencing bleeding, with or without pain, your doctor will examine you.

The doctor will do a physical exam to determine that your cervix is closed and will use one of two tests to check for your baby's heartbeat:

Your doctor may also do a blood test to check your hCG (a pregnancy hormone) level. This test might be repeated a few days later. Your doctor may also continue to monitor your baby with ultrasounds more frequently than usual.

Treatment - What to Do If You Have a Threatened Miscarriage

There's no proven treatment for a threatened miscarriage and there's nothing you can do to change the outcome.

Your doctor may recommend bed rest and avoiding sex, heavy exercise and heavy lifting, but it's important to know that there's no proof that these strategies lower miscarriage rates in threatened miscarriages. These approaches may help you feel more comfortable, though.

One of two things will happen if you have a threatened miscarriage:

  • The bleeding will stop and the pregnancy will continue to term.
  • The bleeding will become heavier and a miscarriage will occur.

Treatment with Progestins

Doctors are researching the use of progestins to prevent miscarriage in women with threatened miscarriage. Although early results show that the treatment is promising, its use is controversial. Although progestins may help some women avoid a miscarriage, they are unlikely to help in cases when there is a genetic problem.

Also Known As: Threatened Abortion, Spontaneous Threatened Abortion

Sources:

Saraswat L, Bhattacharya S, Maheshwari A, Bhattacharya S. Maternal and perinatal outcome in women with threatened miscarriage in the first trimester: a systematic review. BJOG 2010;117:245–257.

Patient information: Miscarriage (Beyond the Basics). UpToDate. July 16, 2015.

Spontaneous abortion: Management. UpToDate. July 15, 2015.

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