Miscarriage

Definition

Miscarriage is the spontaneous loss of a pregnancy before the 20th week. About 15 to 20 percent of known pregnancies end in miscarriage. But the actual number is probably much higher because many miscarriages occur so early in pregnancy that a woman doesn't even know she's pregnant. Most miscarriages occur because the fetus isn't developing normally.


Miscarriage is a relatively common experience — but that doesn't make it any easier. Take a step toward emotional healing by understanding what can cause a miscarriage, what increases the risk and what medical care might be needed.


Miscarriage Statistics

Sadly, miscarriages are a very common occurrence. Sources vary, but many estimate that approximately 1 in 4 pregnancies end in miscarriage; and some estimates are as high as 1 in 3. If you include loss that occurs before a positive pregnancy test, some estimate that 40% of all conceptions result in loss.


Although statistics can vary slightly from one source to the next, here is a general account (based primarily on information provided by the March of Dimes) of the frequency of miscarriages in the United States:



Miscarriage Symptoms

The most common symptom of miscarriage is vaginal bleeding. This can vary from light spotting or brownish discharge, to heavy bleeding and bright red blood. The bleeding may come and go over several days (spotting or bleeding in early pregnancy is fairly common).


Light vaginal bleeding is common during the first trimester of pregnancy (the first 12 weeks), so having this symptom does not necessarily mean that you have had a miscarriage. In most cases, women who experience light bleeding in the first trimester go on to have successful pregnancies. Sometimes even heavier bleeding doesn't result in miscarriage.


However, if you have vaginal bleeding, contact your maternity team or early pregnancy unit at your local hospital straight away.


Other symptoms

Other symptoms of a miscarriage include:



Ectopic pregnancy

On rare occasions, miscarriages happen because the pregnancy develops outside the womb. This is known as an ectopic pregnancy. Ectopic pregnancies are potentially serious because there is a risk that you could experience internal bleeding.


Symptoms of an ectopic pregnancy include:



Symptoms of an ectopic pregnancy usually appear between weeks 5-14 of the pregnancy.

If you experience any of the symptoms above, seek immediate medical attention.


Molar pregnancies

Vaginal bleeding can also be caused by a molar pregnancy. This is a pregnancy that has not developed normally, resulting in a mass of abnormal cells within the womb instead of a baby. A molar pregnancy is usually identified during the first ultrasound scan, at 10-16 weeks of pregnancy.


When to see a doctor

Call your doctor if you experience:



You may bring any tissue that is passed into your doctor's office in a clean container. It's unlikely that any testing would define a cause, but confirming the passage of placental tissue helps your doctor determine that your symptoms aren't related to a tubal (ectopic) pregnancy.


Miscarriage Causes

If a miscarriage happens during the first trimester of pregnancy (the first three months), it is usually due to problems with the unborn baby (fetus).


If a miscarriage happens during the second trimester of pregnancy (between weeks 14 and 26), it is usually the result of an underlying health condition in the mother.


First trimester miscarriages

Most first trimester miscarriages are caused by problems with the chromosomes of the fetus.


Chromosome problems

Chromosomes are blocks of DNA. They contain a detailed set of instructions that control a wide range of factors, from how the cells of the body develop to what color eyes a baby will have.

For a pregnancy to be successful, a fetus needs to have 46 chromosomes in total:



Sometimes, something can go wrong at the point of conception and the fetus receives too many or not enough chromosomes. The reasons for this are often unclear, but it means that the fetus will not be able to develop normally, resulting in a miscarriage.


It is estimated that up to two thirds of early miscarriages are associated with chromosome abnormalities.


Placental problems

The placenta is the organ that links the mother's blood supply to her baby's. If there is a problem with the development of the placenta it can also lead to a miscarriage.


Risk factors

An early miscarriage may happen by chance or unknown reasons. However, there are several known risk factors which increase the risk of problems occurring.


Age

One of the most important risk factor for miscarriage is the age of the mother:



Other risk factors

Other risk factors for having a miscarriage include:



Second trimester miscarriages

Long-term health conditions

There are several long-term (chronic) health conditions that can increase the risk of having a miscarriage. These are:



Infections

There are some infections that may increase the risk of having a miscarriage. These include:



Medicines

Some medicines can also increase the risk of miscarriage:



To be sure that a medicine is safe in pregnancy, always check with your doctor, midwife or pharmacist before taking it.


Antibodies

Antibodies are proteins that are produced by the immune system (the body's natural defense system) to fight infection.


Some women who have had three or more miscarriages in a row (recurrent miscarriages) have a higher than usual level of an antibody called antiphospholipid (aPL) in their blood. The aPL antibodies are known to cause blood clots. These blood clots can block the supply of blood to the fetus, which can cause a miscarriage.


Having a high number of aPL antibodies in your blood is known as Hughes syndrome.


Womb structure

Problems and abnormalities with the womb can also lead to second trimester miscarriages. Possible problems with the structure of the womb include:



Weakened cervix

In some cases, the muscles of the cervix (neck of the womb) are weaker than usual. This is known as a weakened cervix or cervical incompetence. A weakened cervix may be due to a previous injury to this area, or may have been something you were born with.


The muscle weakness can cause the cervix to open too early during pregnancy, leading to a miscarriage.


Hyperprolactinaemia

Prolactin is a hormone which is produced during pregnancy. Prolactin helps to prepare the breasts for breastfeeding. Sometimes, women have a higher level of prolactin in their body than usual. This is known as hyperprolactinaemia.


Some limited evidence suggests that hyperprolactinaemia may be linked to an increased risk of miscarriage.


Polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a condition where the ovaries are larger than normal. It can lead to hormonal imbalances inside the womb.


Polycystic ovary syndrome is known to be a leading cause of infertility. There is some evidence to suggest that it may also be linked to an increased risk of miscarriage in women who are still fertile. However, the exact role that polycystic ovary syndrome plays in miscarriages is unclear.


Misconceptions about miscarriage

There are a number of widely held assumptions about the possible causes of miscarriages. However, there is no evidence to support such claims.


An increased risk of miscarriage is not linked to:



Miscarriage Complications

Most of the time, a first-trimester miscarriage is a tragic but relatively uncomplicated event from a health perspective -- your body recovers fairly quickly and you can go on to get pregnant again without further concerns. Sometimes, however, complications can arise. Make sure to see your doctor if you suspect you have any of these problems.









Some women who miscarry develop a uterine infection, also called a septic miscarriage. Signs and symptoms of this infection include:



Miscarriage Treatments and drugs

Your treatment for a miscarriage depends on whether there is any foetal tissue left in your womb (a complete or incomplete miscarriage).


Complete miscarriage

If there is no fetal tissue left in your womb (a complete miscarriage), no further medical treatment is required. However, a miscarriage can have a significant emotional effect and you and your partner may need counseling or support.


Incomplete miscarriage

If there is fetal tissue left in your womb (an incomplete miscarriage), this needs to be removed as there is a risk that it could become infected. This can be done in three ways:



There are benefits and risks of each option that you should consider when making your decision.


If you have surgery, any bleeding or pain you are experiencing because of your miscarriage should quickly improve. However, all surgical procedures carry their own risks. Medication avoids the need for surgery but can cause increased pain and bleeding. Waiting for the tissue to pass naturally avoids taking medication or having surgery, but can take several weeks. It is also possible that not all of the tissue will be removed, and that you will later require surgery.


Discuss the options with the doctor in charge of your care.


Surgery

Surgery usually takes place within a few days of a miscarriage. However, there are circumstances where you may be advised to have immediate surgery, including:



Surgery is usually performed under general anesthetic. Your cervix (neck of the womb) will be opened with a small tube, known as a dilator, and the tissue will be removed using a suction device. This type of surgery is known as evacuation of retained products of conception (ERPC).


Before surgery, you may be given medication to soften the cervix and to make it easier to perform the surgery.


This type of surgery is usually very safe. However, as with all surgery, there is a small risk of complications.

Possible complications include:


Around 2 in 100 women will experience a serious complication, such as a tear to their womb or cervix.


Medication

Using medication to remove the tissue involves taking tablets that cause the cervix to open, allowing the tissue to pass out. There are two types of tablets:



The effects of the tablets usually begin within a few hours. You will experience symptoms similar to a heavy period, such as cramping and heavy vaginal bleeding. You may also experience vaginal bleeding for up to three weeks.


Medication is successful in removing fetal tissue in around 9 out of 10 cases. However, you will need to have surgery if the medication is unsuccessful.


Waiting method

If you wait for the tissue to pass naturally out of your womb, it may be some time before you experience vaginal bleeding. This tends to be heavier than your usual period and you may also experience cramping. Bleeding can last for up to three weeks.


If the bleeding becomes particularly heavy or you experience severe pain, contact your hospital. You should be given a 24-hour helpline number to call in case of emergency.


For more than half of miscarriages, this method is unsuccessful in removing fetal tissue. In this situation, you will need either medication or surgery.


Treating the cause of the miscarriage

In some cases, if a cause of the miscarriage has been identified, it may be possible to have treatment to prevent this causing any more miscarriages.


Hughes syndrome

Hughes syndrome, an autoimmune condition that causes blood clots, can be treated with medication. Research has shown that a combination of aspirin and heparin (a medicine used to prevent blood clots) can improve pregnancy outcomes in women with Hughes syndrome.


Weakened cervix

A weakened cervix, also known as cervical incompetence, can be treated with an operation to put a small stitch of strong thread around your cervix to keep it closed. This is usually carried out after the first 12 weeks of your pregnancy, and is removed around week 37.


Suggested treatments

Other suggested treatments for recurrent miscarriages have been studied. These include:



However, the results of all these studies have been disappointing so far and there is no evidence that these treatments can prevent miscarriages.


Lifestyle and Home Remedies

Physical recovery

Physical recovery from miscarriage in most cases will take only a few hours to a couple of days. Expect your period to return within six weeks. In the meantime, call your doctor if you experience heavy bleeding, fever, chills or severe pain. These signs and symptoms could indicate an infection. Avoid having sex or putting anything in your vagina — such as a tampon or douche — for two weeks after a miscarriage.


Future pregnancies

It's possible to become pregnant during the menstrual cycle immediately after a miscarriage. But if you and your partner decide to attempt another pregnancy, make sure you're physically and emotionally ready. Your doctor may recommend waiting at least one menstrual cycle, if not longer.

If you experience multiple miscarriages, generally more than three in a row, consider testing to identify any underlying causes - such as uterine abnormalities, coagulation problems or chromosomal abnormalities. In some cases your doctor may suggest testing after two consecutive losses, but two losses are still often due to genes and not to an underlying medical cause. If the cause of your miscarriages can't be identified, don't lose hope. Even without treatment, about 70 percent of women with repeated miscarriages go on to have successful pregnancies.


Coping and Support

Emotional healing may take much longer than physical healing. Miscarriage can be a heart-wrenching loss that others around you may not fully understand. Your emotions may range from anger to despair. Give yourself time to grieve the loss of your pregnancy, and seek help from those who love you. Keeping the loss to yourself isn't necessary.


You'll likely never forget your hopes and dreams surrounding this pregnancy, but in time acceptance may ease your pain. Talk to your doctor if you're feeling profound sadness or depression.


Preventing Miscarriage

In the vast majority of cases, there's nothing you can do to prevent a miscarriage. Simply focus on taking good care of yourself and your baby. Seek regular prenatal care, and avoid known risk factors — such as smoking and drinking alcohol. If you have a chronic condition, work with your health care team to keep it under control.


Even if you take the best care of yourself during pregnancy, you often can't prevent a miscarriage.

However, there are ways to lower your risk of miscarriage:



Your weight

Obesity increases your risk of miscarriage. A person is obese when they have a body mass index (BMI) of over 30. You can check your BMI using the healthy weight calculator. However, if you are pregnant the calculator may not be accurate, so you should consult your midwife or doctor instead.


The best way to protect your health and your baby's wellbeing is to lose weight before you become pregnant. By reaching a healthy weight, you cut your risk of all the problems that are associated with obesity in pregnancy. Contact your GP for advice about how to lose weight. They may be able to refer you to a specialist weight-loss clinic.


As yet, there is no evidence to suggest that losing weight during pregnancy will lower your risk of miscarriage, but eating healthily and activities such as walking and swimming are good for all pregnant women. If you were not active before becoming pregnant, you should consult your midwife or doctor before starting a new exercise regime while you are pregnant.

Read more on if you're pregnant and overweight and find out about exercises and keeping active during pregnancy.


Miscarriage Risk factors

Various factors increase the risk of miscarriage, including: