A miscarriage is the loss of a pregnancy before week 20. About of pregnancies end in miscarriage, though the actual percentage is likely higher because some pregnancies are lost very early, before a woman realizes she is pregnant.

How long a miscarriage lasts can vary, depending on several factors. Read on to learn more about miscarriages.

The risk of a miscarriage increases with age. Women under age 35 have about a chance of miscarriage. Women between the ages of 35 and 45 have a 20–35 percent chance.

If you become pregnant after the age of 45, your chance of miscarriage increases to 80 percent.

A miscarriage can happen to anyone, but the risk is higher if you’ve had prior miscarriages, have a chronic condition such as diabetes, or have uterine or cervical problems.

Other contributing factors include being:

  • smoking
  • alcohol abuse
  • being underweight
  • being overweight

If you experience a miscarriage before realizing you’re pregnant, you may think the bleeding and cramping are due to your menstrual cycle. So, some women have miscarriages and never realize it.

The length of a miscarriage differs for every woman, and it depends on different factors, including:

  • how far along you are in the pregnancy
  • whether you were carrying multiples
  • how long it takes your body to expel the fetal tissue and placenta

A woman early in her pregnancy may have a miscarriage and only experience bleeding and cramping for a few hours. But another woman may have miscarriage bleeding for up to a week.

The bleeding can be heavy with clots, but it slowly tapers off over days before stopping, usually within two weeks.

A miscarriage is the spontaneous loss of a fetus. Most miscarriages take place before week 12 of pregnancy.

Symptoms of a miscarriage may include:

Miscarriages can be caused by many things. Some miscarriages occur because of abnormalities with a developing fetus, such as:

Chromosomal abnormalities caused by an abnormal egg or sperm account for about half of all miscarriages. Another potential cause is trauma to the stomach due to invasive procedures, such as chorionic villus sampling. Early in pregnancy, it would be unlikely that an accident or fall could result in miscarriage, since the uterus is so small and well protected within the bony pelvis.

Other causes include certain maternal diseases that put pregnancies at risk. Some miscarriages are unexplained with no cause known.

Daily activities do not typically cause a pregnancy loss. These include activities like exercise (once your doctor says it’s OK) and sex.

If you think you’re having a miscarriage, seek medical help immediately. Any vaginal bleeding or pelvic pain should be evaluated. There are different tests your doctor can run to determine a miscarriage.

Your doctor will check your cervix during a pelvic examination. Your doctor might perform an ultrasound to check the fetal heartbeat. A blood test can look for the pregnancy hormone.

If you’ve passed pregnancy tissue, bring a sample of the tissue to your appointment so your doctor can confirm the miscarriage.

There are different types of miscarriages. These include:

Threatened miscarriage

During a threatened miscarriage your cervix isn’t dilated, but you do experience bleeding. There is still a viable pregnancy present. There’s a risk of miscarriage, but with observation and medical intervention, you may be able to continue the pregnancy.

Inevitable miscarriage

An inevitable miscarriage is when your cervix is dilated and your uterus is contracting. You may already be passing some of the pregnancy tissue vaginally. This is a miscarriage already in progress.

Incomplete miscarriage

Your body releases some fetal tissue, but some of the tissue remains in your uterus.

Missed miscarriage

During a missed miscarriage, the embryo has died, but the placenta and embryonic tissue remain in your uterus. You may not have any symptoms, and the diagnosis is made incidentally on an ultrasound exam.

Complete miscarriage

During a complete miscarriage your body passes all the pregnancy tissue.

If you ignore a possible miscarriage, you could develop septic miscarriage, which is a rare but serious uterine infection. Symptoms of this complication include a fever, chills, abdominal tenderness, and foul-smelling vaginal discharge.

Treatments vary according to the type of miscarriage. With a threatened miscarriage, your doctor may recommend you rest and limit activity until the pain and bleeding stop. If there’s a continued risk for a miscarriage, you may have to remain on bed rest until labor and delivery.

In some cases, you can let a miscarriage progress naturally. This process can take up to a couple of weeks. Your doctor will review bleeding precautions with you and what to expect. A second option is for your doctor to give you medication to help you pass the pregnancy tissue and placenta faster. This medication can be taken orally or vaginally.

Treatment is usually effective within 24 hours. If your body doesn’t expel all the tissue or placenta, your doctor can perform a procedure called dilation and curettage (D and C). This involves dilating the cervix and removing any remaining tissue. You could also discuss having a D and C with your doctor as first-line treatment, without using medication or letting your body pass the tissue on its own.

A pregnancy loss can occur even if you do eliminate risk factors like smoking and drinking. Sometimes, there’s nothing you can do to prevent a miscarriage.

After a miscarriage, you can expect a menstrual cycle within about four to six weeks. After this point, you can conceive again. You can also take precautions against having a miscarriage. These include:

  • taking prenatal vitamins
  • limiting your caffeine intake to 200 milligrams per day
  • managing other medical conditions you may have, such as diabetes or high blood pressure

Having a miscarriage doesn’t mean you can’t have a baby. But if you have multiple miscarriages, your doctor may suggest testing to determine if there is an underlying cause.