Patient information from BMJ

Miscarriage

Last published:Oct 14, 2020

A miscarriage is the unexpected loss of a pregnancy. This can be deeply sad and upsetting for people trying for a baby. Miscarriages can happen to anyone. Most people go on to have healthy pregnancies and babies in future.

What is a miscarriage?

A miscarriage happens when a pregnancy ends unexpectedly before the developing baby is old enough to survive on its own. Miscarriages can happen as late as the 22nd week of pregnancy, but most (97 in every 100) happen during the first 12 weeks.

We do not know exactly how many pregnancies end in miscarriage, because sometimes people with an early miscarriage do not know they were pregnant. Doctors think between 10 in 100 and 30 in 100 pregnancies end in miscarriage.

Most people never know why their pregnancy ended in miscarriage. Studies show that most miscarriages happen because of problems that stop the baby from developing and growing.

These are usually random genetic errors that happen in the early stages of growth, not genetic problems inherited from the parents.

Any woman can miscarry. However, certain things make it more likely. These are called risk factors. Having a risk factor doesn't mean you will have a miscarriage. It just means you have a greater chance than someone without the risk factor of having a miscarriage. Risk factors for miscarriage include:

• older age: a woman's chance of having a miscarriage increases as she gets older. Your risk at age 45 is eight times higher than at age 20. The risk of miscarriage also increases as the father gets older.

• abnormalities in the womb: having an unusually short or weak opening to your womb (cervix) can increase your risk. So can large fibroids (non-cancerous lumps in the womb).

• medical conditions: certain long-term diseases, such as thyroid problems, make a miscarriage more likely. Good antenatal care can reduce this risk.

• blood-clotting disorders: people with these disorders, called thrombophilias, form blood clots too easily. This increases the chance of miscarriage.

• obesity: women who are very overweight (obese) have a greater chance of miscarriage.

• two or more previous miscarriages: if you have had more than one miscarriage before, you are more likely to miscarry again. But if you have had only one miscarriage, you are no more likely to miscarry than women who have never miscarried before.

• smoking or using illegal drugs while pregnant: drinking a lot of caffeine may also increase your risk, although there is only weak evidence that caffeine is linked to miscarriage.

Despite what you might have heard, the following things don't increase your chance of miscarriage:

• exercising

• having sex

• working (as long as you're not working with harmful substances), and

• having an internal examination by a midwife or doctor.

What are the symptoms?

These symptoms may mean you are having a miscarriage:

• Bleeding or spotting: this can be light or heavy. Many women get some bleeding in their first 12 weeks and this does not always lead to miscarriage.

• Abdominal cramps: the cramping can be on one side, on both sides, or in the middle. The pain may be like period pain, or it can be more severe.

  You should always get medical help if you have severe cramps when pregnant. It could be a sign of an ectopic pregnancy (where the embryo grows outside the womb), which needs emergency treatment.

• Low back pain: this is sometimes described as a persistent, dull ache.

• Fluid or tissue passing from your vagina.

These symptoms don't automatically mean you're miscarrying, but you should see your doctor straight away to have them checked out. Your doctor will ask you questions about your symptoms and pregnancy. You will probably be referred to the Early Pregnancy Unit at your local hospital. You are likely to have:

• a pelvic examination: this can show whether your cervix has begun to open (dilate), which is a sign of miscarriage.

• blood tests: one of the main tests measures a hormone called beta hCG.

• an ultrasound scan: this is used to check for a heartbeat and whether the baby is developing normally.

Women’s experience of miscarriage varies a lot. For some women, it’s similar to the experience of having a monthly period. But it can be frightening, especially if you are in a lot of pain and bleeding heavily.

You should be offered painkillers to make you more comfortable. Rarely, women with heavy bleeding need blood or plasma transfusions. But it’s very rare for a miscarriage to cause lasting health problems.

What treatments work?

There’s nothing you can do to prevent or stop a miscarriage. The aim of treatment is to make you as comfortable as possible, and to help your body recover.

Your doctor may describe your miscarriage as missed, incomplete, or complete. This is about whether the tissues from your pregnancy, including the baby and the placenta, have passed out of your body.

• A missed miscarriage means that the pregnancy has ended but the tissues remain in the womb.

• An incomplete miscarriage means that some, but not all, of the tissues have left the body.

• A complete miscarriage means that all the tissues have passed from the body.

Many women who miscarry early in their pregnancy will have a complete miscarriage by the time they see their doctor or soon after. These women do not need further treatment for their miscarriage.

But if a miscarriage is not complete, there are three treatment options. Many hospitals suggest letting the miscarriage finish naturally if possible. You may need surgery if you are bleeding heavily, or if you have any signs of infection.

• Letting the miscarriage finish naturally: After a pregnancy has ended, it can take two to four weeks for all the tissues to leave your body. With an early miscarriage, you are not likely to see the baby.

  Most women who have an early miscarriage only see blood clots. When you have stopped bleeding, the miscarriage is probably complete. You might need an ultrasound scan to check, but this is not often needed.

• Drug treatment: Medicines can help the cervix to open, allowing the tissues to pass out. You may be offered a tablet called misoprostol to put into your vagina.

• Minor surgery: Your doctor can remove the tissues through a surgical procedure. Doctors call this evacuation of retained products of conception (ERPC), or surgical evacuation. Your doctor will gently stretch the neck of your womb and insert a tube to empty the womb. You'll probably have a general anaesthetic, so you'll be asleep for this procedure.

What will happen to me?

Some women bleed for several weeks after a miscarriage. If you've lost a lot of blood, you may need to take iron tablets to avoid anaemia. You may feel very tired, and find you get upset easily.

As well as the trauma and sadness, your body is dealing with changes in hormone levels, which can affect your emotions.

Grieving and emotional recovery

Women react to miscarriage in different ways. You may feel you need to take it slowly and take time off work. Or you may feel better soon and want to get back to your normal routine.

However, the emotional impact of a miscarriage can take longer to heal. You and your partner should be offered counselling to help you work through your emotions. You may feel grief, shock, disappointment, disbelief, anger, and even guilt.

These feelings can take time to surface and to deal with. Talking to a counsellor, and having the support of family and friends, can help you through this grieving process.

Trying again

A woman's body quickly recovers from a miscarriage, and some people start trying to get pregnant again soon after. There is no medical reason to delay trying again if you want to.

If you want to try again, you can start planning for your next pregnancy. Most women who have one miscarriage go on to have a successful pregnancy next time around.

If you've had three or more miscarriages, your doctor may suggest you have tests, to see whether there is a particular cause.

You’ll probably have blood tests for antiphospholipid syndrome, which is a blood-clotting disorder. But because miscarriage is so common, you probably won’t have tests if you've had fewer than three miscarriages.

There are various organisations and groups that support people affected by miscarriage. For example, in the UK, The Miscarriage Association (miscarriageassociation.org.uk) offers help and information.