Miscarriage: Types, Causes, Symptoms, Diagnosis & Treatment

Miscarriage (also called a spontaneous abortion) is the unexpected loss of pregnancy in the first 20 weeks of gestation. It typically happens during the first trimester, or first three months of a pregnancy.

About 10% to 20% of known pregnancies end in miscarriage. But the actual number is likely higher. This is because many miscarriages happen early on, before people realize they’re pregnant.

Miscarriages can happen for a variety of medical reasons, many of which aren’t within a person’s control. But knowing the risk factors, signs, and causes can help you better understand the event and get any support or treatment you may need.

Types of miscarriage

There are many different types of miscarriage. Depending on your symptoms and the stage of your pregnancy, your doctor will diagnose your condition as one of the following:

• Complete miscarriage: All pregnancy tissues have been expelled from your body.
• Incomplete miscarriage: You’ve passed some tissue or placental material, but some still remains in your body.
• Missed miscarriage: The embryo dies without your knowledge, and you don’t deliver it.
• Threatened miscarriage: Bleeding and cramps point to a possible upcoming miscarriage.
• Inevitable miscarriage: The presence of bleeding, cramping, and cervical dilation indicates that a miscarriage is inevitable.
• Septic miscarriage: An infection has occurred within your uterus.
• Recurrent miscarriage: Three consecutive miscarriages. It affects about 1% of couples.

Miscarriage with twins

Twins typically happen when two eggs are fertilized instead of one. They can also happen when one fertilized egg splits into two separate embryos.

Naturally, there are additional considerations when a woman is pregnant with twins. Having multiple babies in the womb can affect growth and development. Women who are pregnant with twins or other multiples may be more likely to have complications such as preterm birth, preeclampsia, or miscarriage.

Additionally, a type of miscarriage called vanishing twin syndrome can affect some who are pregnant with twins. Vanishing twin syndrome occurs when only one fetus can be detected in a woman who was previously determined to be pregnant with twins.

In many cases, the vanished twin is reabsorbed into the placenta. Sometimes this happens so early in the pregnancy that you didn’t even know you were pregnant with twins.

Symptoms of miscarriage

Most miscarriages happen during the first trimester of pregnancy, which is about the first 13 weeks. The symptoms of a miscarriage vary, depending on your stage of pregnancy. In some cases, it happens so quickly that you may not even know you’re pregnant before you miscarry.

Here are some of the symptoms of a miscarriage:

• Bleeding from the vagina with or without pain, including light bleeding called spotting.
• Pain or cramping in the pelvic area or lower back.
• Fluid or tissue passing from the vagina.
• Fast heartbeat.
• A decrease in pregnancy symptoms.

Call your doctor right away if you experience any of these symptoms during your pregnancy. It’s also possible to have these symptoms without experiencing a miscarriage. But your doctor will want to conduct tests to make sure that everything is fine.

You can also read about: Types and Symptoms of Uterine Fibroids

Causes of miscarriage

Chromosomal abnormalities cause about 50% of all miscarriages in the first trimester (up to 13 weeks) of pregnancy. Chromosomes are tiny structures inside the cells of your body that carry your genes. Genes determine all of a person’s physical attributes, such as assigned sex, hair and eye color and blood type.

During fertilization, when the egg and sperm join, two sets of chromosomes come together. If an egg or sperm has more or fewer chromosomes than normal, the fetus will have an abnormal number. As a fertilized egg grows into a fetus, its cells divide and multiply several times. Abnormalities during this process also leads to miscarriage.

Most chromosomal problems occur by chance. It’s not completely known why this happens.

Genetic or chromosome issues

Chromosomes hold genes. In a developing fetus, one set of chromosomes is contributed by the mother and another by the father.

Examples of these chromosome abnormalities include:

• Intrauterine fetal demise: The embryo forms but stops developing before you see or feel symptoms of pregnancy loss.
• Blighted ovum: No embryo forms at all.
• Molar pregnancy: Both sets of chromosomes come from the father, no fetal development occurs.
• Partial molar pregnancy: The mother’s chromosomes remain, but the father has also provided two sets of chromosomes.

Errors can also occur randomly when the cells of the embryo divide, or due to a damaged egg or sperm cell. Problems with the placenta can also lead to a miscarriage.

Underlying conditions and lifestyle habits

Various underlying health conditions and lifestyle habits may also interfere with the development of a fetus. Exercise and sexual intercourse do not cause miscarriages. Working won’t affect the fetus either, unless you’re exposed to harmful chemicals or radiation.

Conditions that can interfere with fetus development include:

• poor diet, or malnutrition
• drug and alcohol use
• advanced maternal age
• untreated thyroid disease
• issues with hormones
• uncontrolled diabetes
• infections
• trauma
• Obesity
• problems with the cervix
• abnormally shaped uterus
• severe high blood pressure
• food poisoning
• certain medications

Always check with your doctor before taking any medications to be sure a drug is safe to use during pregnancy.

Risk factors of miscarriage

Most miscarriages are due to natural and unpreventable causes. However, certain risk factors can increase your chances of having a miscarriage. These include:

• Age. If you’re older than age 35, you have a higher risk of miscarriage than a younger person. At age 35, you have about a 20% risk. At age 40, the risk is about 33% to 40%. And at age 45, it ranges from 57% to 80%.
• Past miscarriages. If you’ve had one or more prior miscarriages before, you’re at higher risk of pregnancy loss.
• Long-term conditions. If you have an ongoing health condition, such as uncontrolled diabetes, you have a higher risk of miscarriage.
• Uterine or cervical problems. Certain uterine conditions or weak cervical tissues, also called incompetent cervix, might raise the chances of a miscarriage.
• Smoking, alcohol, caffeine and illegal drugs. People who smoke have a greater risk of miscarriage than do nonsmokers. Heavy use of caffeine or alcohol use also raises the risk. So does using illegal drugs such as cocaine.
• Weight. Being underweight or being overweight has been linked with a higher risk of miscarriage.
• Genetic conditions. Sometimes, one of the partners may be healthy but carry a genetic problem that raises the risk of a miscarriage. For example, one partner could have a unique chromosome that formed when the pieces of two different chromosomes attached to each other. This is called translocation. If either partner carries a chromosome translocation, passing it to an unborn child makes a miscarriage more likely.

Talk to your pregnancy care provider about the risk factors for miscarriage. They can discuss your risk after they’ve reviewed your medical history.

You can also read about: Causes and Risk factors of Preeclampsia

Complications of miscarriage

Sometimes, pregnancy tissue that stays in the uterus after a miscarriage can lead to a uterine infection about 1 to 2 days later. The infection is called a septic miscarriage. Symptoms include: 

• Fever higher than 100.4 degrees Fahrenheit more than two times.
• Chills.
• Pain in the lower stomach area.
• Foul-smelling fluid called discharge from the vagina.
• Vaginal bleeding.

Call your health care professional’s office or your local OB triage or emergency department if you have these symptoms. The illness can get worse fast and become life-threatening without treatment.

Heavy bleeding from the vagina, called a hemorrhage, is another miscarriage complication. Along with the bleeding, a hemorrhage often happens with symptoms such as:

• Fast heartbeat.
• Dizziness from low blood pressure.
• Tiredness or weakness due low red blood cells, also called anemia.

Get medical care at once. Some people who have a hemorrhage need blood from a donor or surgery.

Prevention of miscarriage

Not all miscarriages can be prevented. However, you can take steps to help maintain a healthy pregnancy. Here are a few recommendations:

• Get regular prenatal care throughout your pregnancy.
• Avoid alcohol, drugs, and smoking while pregnant.
• Maintain a healthy weight before and during pregnancy.
• Avoid infections. Wash your hands thoroughly, and stay away from people who are already sick.
• Limit the amount of caffeine to no more than 200 milligrams per day.
• Take prenatal vitamins to help ensure that you and your developing fetus get enough nutrients.
• Eat a healthy, well-balanced diet with lots of fruits and vegetables.

Remember that having a miscarriage doesn’t mean you won’t conceive again in the future. Most women who miscarry have healthy pregnancies later. Get additional information about ways to prevent miscarriage.

You can also read about: Complications and Prevention of Abnormal Uterine Bleeding

Diagnosis of miscarriage

Your health care provider might do a variety of tests to rule out miscarriage, these include:

• Ultrasound. These test check for fetal heartbeat or the presence of a yolk sac (one of the first fetal structures your provider can see on ultrasound).
• Blood tests. To measure human chorionic gonadotropin (hCG), a hormone produced by the placenta. A low hCG level can confirm a miscarriage.
• Pelvic exam. To check if the lower end of your uterus, called the cervix, has begun to open. If it has, that makes a miscarriage more likely.
• Tissue tests. If you’ve passed what looks like tissue, it can be sent to a lab to confirm that a miscarriage has happened — and that your symptoms aren’t tied to another cause.
• Chromosomal tests. If you’ve had two or more previous miscarriages, your health care professional may recommend blood tests for both you and your partner. The tests can help find out if your or your partner’s chromosome make-up might be linked with increased risk for miscarriage.

What tests should I have after repeat miscarriages?

Blood tests or genetic tests might be necessary if you’ve more than three miscarriages in a row (called repeated miscarriage). These include:

• Genetic tests: You and your partner can have blood tests, like karyotyping, to check for chromosome abnormalities. If tissue from the miscarriage is available, your provider may be able to test it for chromosome irregularities.
• Blood tests: You may have a blood test to check for autoimmune or hormone conditions that could be causing miscarriages.

Your provider may also look at your uterus using one of the following procedures:

• Hysterosalpingogram (an X-ray dye test of your uterus and fallopian tubes).
• Hysteroscopy (a test during which your provider views the inside of your uterus with a thin, telescope-like device).
• Laparoscopy (a procedure during which your provider views the pelvic organs with a lighted device).

Treatments of miscarriage

If you have bleeding from the vagina early in your pregnancy, your health care team might recommend that you rest until your symptoms get better. Bed rest and other treatments haven’t been proved to prevent miscarriage, but sometimes they’re prescribed as a safeguard. Don’t use tampons or have sex while you still have bleeding, because these could lead to an infection of the uterus.

In some cases, it’s also a good idea to delay any traveling, especially to areas where it would be hard to get medical care quickly. Ask your health care team if you should put off any trips you’ve planned.

If tests show that you’re having or will have a miscarriage, your health care team might recommend one of the following treatment choices:

• Expectant management. If you have no symptoms of an infection, you might choose to let the miscarriage progress naturally. This often happens within a couple of weeks of finding that the embryo has died. But it might take up to eight weeks. This can be an emotional time. Most often, expectant management is used in the first trimester. If the pregnancy tissue isn’t passed from the body on its own, you’ll need treatment with medicines or surgery.
• Medical treatment. This helps the uterus pass pregnancy tissue out of the body. A combination of the medicines mifepristone (Korlym, Mifeprex) and misoprostol (Cytotec) is more effective than is misoprostol alone. Combined treatment has a higher rate of helping the body release all remaining pregnancy tissue. Mifepristone combined with misoprostol also is linked with a lower risk of needing surgery to complete treatment compared with misoprostol alone.
• Surgical treatment. Another option is a minor procedure called suction dilation and curettage (D&C). During this procedure, your health care team opens your cervix and removes tissue from the inside of your uterus. The procedure also is called uterine aspiration. Complications are rare, but they might include damage to the connective tissue of the cervix or the wall of the uterus. You need surgical treatment if you have a miscarriage along with heavy bleeding or signs of an infection.

After a miscarriage, if you are blood type Rh negative, you also may get a shot of medicine called Rh immunoglobulin. Ask your health care team about your blood type and need for Rh immunoglobulin. If you are RH positive, you will not need Rh immunoglobulin. The shot can help prevent problems with a future pregnancy. It’s given to some people whose blood type is Rh negative, often depending on how many weeks they were pregnant. Rh negative means you don’t have a protein in your blood called Rh factor. If you get pregnant again and the unborn baby is Rh positive, meaning its blood has the protein, that can lead to life-threatening anemia or other problems for the baby.

You can also read about: Diagnosis and Treatments of Ectopic Pregnancy

Physical recovery

In most cases, physical recovery from miscarriage takes only a few hours to a couple of days. In the meantime, call your health care professional if you have:

• Heavy bleeding, such as soaking through more than two menstrual pads an hour for more than two hours in a row.
• Fever.
• Chills.
• Belly pain.

Most people who have a miscarriage get their period about two weeks after any light bleeding or spotting stops. You can start using any type of birth control right after a miscarriage. But don’t have sex or put anything in your vagina, such as a tampon, for 1 to 2 weeks after a miscarriage. This helps prevent an infection.

Most women (87%) who have miscarriages have subsequent normal pregnancies and births. Having a miscarriage doesn’t necessarily mean you have a fertility problem. Remember, most miscarriages occur because of a chromosomal abnormality, not because of something you did.

The decision on when you should begin trying to get pregnant again is between you and your pregnancy care provider. Most women can get pregnant again after they’ve had one “normal” menstrual period.

Taking time to heal both physically and emotionally after a miscarriage is important. Counseling is available to help you cope with your loss. A pregnancy loss support group might also be a valuable resource to you and your partner. Ask your healthcare provider for more information about counseling and support groups. Above all, don’t blame yourself for the miscarriage. Take the time you need to grieve.

If you’ve had three miscarriages in a row, ask your provider about performing tests to figure out an underlying cause. You should use birth control until you receive the results. After your provider reviews the test results, they may suggest going off birth control and trying to conceive again.

Conclusion

A miscarriage is a very emotional moment for expectant parents and it’s natural to grieve the loss. Remember that a miscarriage can’t be prevented, and it’s not caused by something you did wrong. It doesn’t mean that you can’t have children or that you’ll have another miscarriage. If you’re planning to become pregnant, reach out to your healthcare provider to discuss the timing of your next pregnancy and ask any questions you have. It’s OK to be sad. Find support from family, friends online support groups or a licensed counselor.