A miscarriage is the loss of a pregnancy during the first 23 weeks.
The main sign of a miscarriage is vaginal bleeding, which may be followed by cramping and pain in your lower abdomen.
If you have vaginal bleeding, contact your GP or midwife. Most GPs can refer you to an early pregnancy unit at your local hospital straight away if necessary. You may be referred to a maternity ward if your pregnancy is at a later stage.
However, bear in mind that light vaginal bleeding is relatively common during the first trimester of pregnancy (the first 12 weeks) and doesn't necessarily mean you're having a miscarriage.
Read more about the symptoms of miscarriage.
There are probably many reasons why a miscarriage may happen, although the cause isn't usually identified. The majority aren't caused by anything the mother has done.
It's thought most miscarriages are caused by abnormal chromosomes in the baby. Chromosomes are genetic "building blocks" that guide the development of a baby. If a baby has too many or not enough chromosomes, it won't develop properly.
If a miscarriage happens during the second trimester of pregnancy (between weeks 14 and 26), it's sometimes the result of an underlying health condition in the mother.
For most women, a miscarriage is a one-off event and they go on to have a successful pregnancy in the future.
Read more about what causes a miscarriage.
The majority of miscarriages can't be prevented. If a woman has suffered from more than three miscarriages, some women can be helped to keep their pregnancy with medication under the care of a specialist.
However, there are some things you can do to reduce the risk of a miscarriage. Avoid smoking, drinking alcohol and using drugs while pregnant. Being a healthy weight before getting pregnant, eating a healthy diet and reducing your risk of infection can also help.
Read more about preventing miscarriages.
If you have the symptoms of a miscarriage, you'll usually be referred to a hospital for tests. In most cases, an ultrasound scan can determine whether the pregnancy is ongoing or you're having a miscarriage.
When a miscarriage is confirmed, you'll need to talk to your doctor or nurse about the options for the management of the end of the pregnancy.
In the majority of cases, the pregnancy tissue will pass out naturally in a week or two. Sometimes medication to assist the passage of the tissue may be recommended, or you can choose to have minor surgery to remove it if you don't want to wait.
A miscarriage can be an emotionally and physically draining experience. You may have feelings of guilt, shock and anger.
Advice and support is available at this time from hospital counselling services and charity groups. You may also find it beneficial to have a memorial for your lost baby.
You can try for another baby as soon as your symptoms have settled and you've had one period, although you should ensure you're emotionally and physically ready first.
Having a miscarriage doesn't necessarily mean you'll have another if you get pregnant again. Most women are able to have a healthy pregnancy after a miscarriage, even in cases of recurrent miscarriages.
Read more about what happens after a miscarriage.
Miscarriages are much more common than most people realise. Among women who know they're pregnant, it's estimated one in six of these pregnancies will end in miscarriage. Many more miscarriages occur before a woman is even aware she has become pregnant.
Losing three or more pregnancies in a row (recurrent miscarriages) is uncommon and only affects around 1 in 100 women.