What causes bleeding during pregnancy?

Bleeding during pregnancy is relatively common, with around one in 10 women experiencing some bleeding.

However, always contact your GP or midwife immediately if you have bleeding at any stage during your pregnancy. It’s not often caused by something serious, but it’s important to make sure. Lie down and rest until you can see a healthcare professional and do not take any medication while you are waiting.

Early pregnancy

In early pregnancy, you might get some light bleeding called "spotting", when the foetus plants itself into the wall of your womb. This is also known as implantation bleeding and it often occurs around the time that your first period after conception would have been due.

During the first three months of pregnancy, vaginal bleeding can be a sign of miscarriage or ectopic pregnancy (when the foetus starts to grow inside your fallopian tubes instead of your womb).

Most miscarriages occur during the first 12 weeks of pregnancy and, sadly, most cannot be prevented. Ectopic pregnancies are much less common than miscarriages, affecting about one in 100 pregnancies.

Later stages of pregnancy

In the later stages of pregnancy, vaginal bleeding can have many different causes. Some of the more common causes are described below.

Cervical ectropion

Cervical ectropion is where there are harmless changes in the neck of the womb (cervix). It’s the most common cause of bleeding during the later stages of pregnancy.

A "show"

A "show" is where a plug of mucus from the cervix comes away just before labour. It can look like a lump of discharge and may be bloodstained. If it happens before you are due to give birth, it might be a sign of early labour.

Placental abruption

Placental abruption is a serious condition where the placenta starts to come away from the inside of the womb wall. It usually causes stomach pain, even if there is no bleeding. If it happens close to your baby's due date, your baby may be delivered early.

Placenta praevia

Placenta praevia is where the placenta lies low in the womb, partially or completely blocking the baby's path to the cervix.

The placenta usually moves gradually upwards during pregnancy, but if it's still low when the baby is due to be born, you might need to have a Caesarean section (where the baby is delivered through an incision in your tummy and womb).

Miscarriage

Vaginal bleeding in the later stages of pregnancy can also be a sign of a miscarriage. However, miscarriages are very rare after the third month of pregnancy.

Finding the cause of your bleeding

To work out what is causing your bleeding, you may need to have a vaginal or pelvic examination, an ultrasound scan, or blood tests to check your hormone levels. Your doctor will also ask you about other symptoms, such as cramp, pain and dizziness, and what foods, medication and exercise you've been taking recently.

If your symptoms are not severe and your baby is not due for a while, you will be monitored and, in some cases, kept in hospital for observation. You might have to stay in overnight or until the birth, depending on the cause of the bleeding and how far you are into your pregnancy. This will enable staff to keep an eye on you and your baby so that they can act quickly if there are any further problems.

Further information:

Page last reviewed: 16/05/2013

Next review due: 15/05/2015