Many women experience some bleeding in early pregnancy. About 1 in 5 recognised pregnancies end in miscarriage. Most are caused by a one-off fault in the genes. Seek medical advice if you have vaginal bleeding when you are pregnant.
Call an ambulance if the bleeding is very heavy or if you have severe tummy (abdominal) pain. Bleeding with pain can also be a sign of an ectopic pregnancy. This is less common than miscarriage but is serious and needs urgent medical care.
Losing a pregnancy can be hard for both partners. However, most couples who experience this will go on to have a successful pregnancy next time.
What causes bleeding in early pregnancy?
About 25 out of 100 pregnant women have a small amount of bleeding (spotting) at the time of their missed period. This is sometimes called an 'implantation bleed', because it happens when the fertilised egg implants itself in the wall of the womb (uterus). It is harmless.
The most common cause of bleeding after the time of the missed period is a miscarriage. Miscarriage is the loss of a pregnancy at any time up to the end of the 24th week. A loss after this time is called a stillbirth.
More than 8 miscarriages out of 10 occur before 13 weeks of pregnancy. These are called early miscarriages. A late miscarriage is one that happens from 13 weeks to 24 weeks of pregnancy.
A less common cause of bleeding in pregnancy is an ectopic pregnancy. This is a pregnancy that occurs outside the womb. It occurs in about 1 in 100 pregnancies. This is a medical emergency. It is important to seek medical advice with bleeding in pregnancy - this should be sought urgently if the bleeding is heavy (heavier than a normal period) or there is pain.
How common is miscarriage?
About one in four recognised pregnancies end in miscarriage. It is thought that about half of all pregnancies end in miscarriage but that half of these are so early that women may be unaware that they are pregnant.
The vast majority of women who miscarry go on to have a successful pregnancy next time.
Recurrent miscarriages (three or more miscarriages in a row) occur in about 1 in 100 women.
Why do miscarriages happen? When is a miscarriage most likely to occur? Who should you call if you have a miscarriage? All your questions answered.
What causes miscarriage?
It is thought that most early miscarriages are caused by a one-off problem with the chromosomes of the developing baby (fetus) in the womb. Chromosomes are the structures that contain the genetic information inherited from the parents.
If a baby (fetus) doesn't have the correct chromosomes, it can't develop properly and so the pregnancy will end. This is usually a one-off event and rarely occurs again. Such genetic errors become more common as the mother gets older. Approximately eight out of 100 pregnancies end in miscarriage in women under the age of 30; this number increases to 16 out of 100 in women aged between 35 and 37, to 33 out of 100 in women aged between 40 and 41 and to 60 out of 100 in women aged between 44 and 46.
The risk of miscarriage also increases with increasing age of the father. In women under 30, the age of the father does not seem to make a difference. However in women over 30, there is an increased risk of miscarriage if the father is over 40.
Women are also at a greater risk of having a miscarriage if they:
- Smoke. The risk increases the more cigarettes you smoke.
- Drink too much alcohol. Drinking four units of alcohol a week (one unit is half a pint of beer or a small glass of wine) has been shown to increase the risk of miscarriage.
- Use recreational drugs.
- Have had fertility problems or it has taken a long time to conceive.
- Have any abnormalities of the womb (uterus) or a weakness of the neck of the womb (the cervix).
- Have certain medical conditions (for example, systemic lupus erythematosus, antiphospholipid syndrome).
- Have diabetes mellitus that is not well controlled.
- Have particular infections like listeria and German measles (rubella).
Investigations into the cause of a miscarriage are not usually carried out until after three or more miscarriages in a row. This is because most women who miscarry will not miscarry again.
Two miscarriages are more likely to be due to chance than to some underlying cause. Even after three miscarriages in a row, six women out of every ten will have a successful pregnancy next time around.
Some myths about the cause of miscarriage
After a miscarriage, many women feel guilty and to blame the miscarriage on something they have done or failed to do. This is almost never the case. In particular, miscarriage is not caused by lifting, straining, working too hard, constipation, straining at the toilet, sex, eating spicy foods or taking normal exercise.
There is no evidence that waiting for a certain length of time after a miscarriage improves the chances of having a healthy pregnancy next time.
What is a threatened miscarriage?
It is common to have some light vaginal bleeding at some point in the first 12 weeks of pregnancy. This does not always mean a miscarriage will happen. Often the bleeding settles and the developing infant is healthy. This is called a threatened miscarriage. It is unusual to have pain with a threatened miscarriage. If the pregnancy continues, there is no harm done to the baby.
In some cases, a threatened miscarriage progresses to a miscarriage.
What are the symptoms of miscarriage?
The usual symptoms of miscarriage are:
- Vaginal bleeding.
- Lower tummy (abdominal) cramps.
The time it takes for the bleeding to settle varies. It is usually a few days but can last two weeks or more. For most women, the bleeding is heavy with clots but not severe - it is more like a heavy period. However, the bleeding can be extremely heavy in some cases.
Missed miscarriage (no symptoms)
In some cases of miscarriage, there are no symptoms. The baby stops developing and dies but remains in the womb. There is no pain or bleeding. Some women will stop experiencing pregnancy symptoms (for example, morning sickness or breast tenderness).
This type of miscarriage may not be found until a routine ultrasound scan. This may be referred to by doctors as a missed miscarriage.
The typical pain with a miscarriage is crampy lower tummy pain. Severe, sharp, or one-sided tummy pain may suggest ectopic pregnancy. This is a pregnancy that develops outside the womb.
The symptoms of an ectopic pregnancy usually occur at around 6-8 weeks of pregnancy. There may be very little blood lost or the blood may look almost black. Other symptoms may also occur such as diarrhoea, feeling faint and pain on opening the bowels. Medical advice should be sought urgently with any symptoms of an ectopic pregnancy.
Ruptured ectopic pregnancy
Sometimes there are no symptoms before heavy bleeding into the inside of the abdomen (internal bleeding) causes a collapse. This is called a ruptured ectopic pregnancy and is a potentially life-threatening situation that needs emergency surgery.
Always call an ambulance or go immediately to the nearest Accident and Emergency department if you are worried that you may have a ruptured ectopic pregnancy.
Do I need to go to hospital?
Any bleeding in pregnancy should be reported. It is important to get the correct diagnosis, as miscarriage is not the only cause of vaginal bleeding.
Most women with bleeding in early pregnancy are seen by a doctor who specialises in pregnancy - an obstetrician. This is often in an Early Pregnancy Assessment Unit at the local hospital. Some early pregnancy units allow women to self-refer into them; others require a GP referral or referral from a doctor in ED. It is usual to have an ultrasound scan. This is usually done by inserting a small probe inside your vagina. This helps to determine whether the bleeding is due to:
- A threatened miscarriage (a heartbeat will be seen inside the womb (uterus)).
- A miscarriage (no heartbeat is seen).
- Some other cause of bleeding (such as an ectopic pregnancy - see above).
Sometimes blood tests to look for the pregnancy hormone (beta-HCG) are used. If it is unclear from the ultrasound scan or blood tests whether the pregnancy is healthy or not then a repeat scan in one to two weeks is often suggested.
Women who have already had a scan confirming the baby's heartbeat and who have never had a miscarriage before may be advised that they do not need another scan. However, the early pregnancy unit will advise further on this.
Women who have had a scan confirming the presence of a heartbeat and who have had a previous miscarriage should be offered vaginal progesterone pessaries to be used until the end of the 16th week of pregnancy. This will be arranged in the early pregnancy unit.
Do I need any treatment for miscarriage?
Once the cause of bleeding is known, treatment options will be discussed.
Natural or expectant management
Many women now opt to 'let nature take its course'. This is called expectant management. In most cases the remains of the pregnancy are passed out through the vagina and the bleeding stops within a few days of this, although can take up to 14 days to occur.
However, if the bleeding worsens and becomes heavier or does not settle then alternative treatment may be offered. Expectant management may not be advised if there has been a previous miscarriage or if there is a bleeding disorder or any evidence of infection.
Some women prefer to have a definitive treatment rather than taking this approach.
Treatment with medicines
In some cases medical treatment for a miscarriage is suggested. This is a tablet taken either by mouth or inserted into the vagina. This medicine helps to empty the womb (uterus) and can have the same effect as an operation.
Some women experience quite severe tummy (abdominal) cramps with this treatment. It is possible to continue to bleed for up to three weeks when medical treatment is used. However, the bleeding should not be too heavy. Many women prefer this treatment because it usually means that they do not need to be admitted to hospital and do not need an operation.
An operation may be offered if the bleeding does not stop within a few days, or if the bleeding is severe.
Treatment with an operation
If the options above are not suitable or are not successful then an operation is likely to be offered. The operation most commonly performed to remove the remains of the pregnancy is called surgical management of miscarriage (SMM).
In this operation, the neck of the womb (the cervix) is gently opened and a narrow suction tube is placed into the womb to remove the remains of the pregnancy. This operation takes around 10 minutes.
This may be performed without the need for a general anaesthetic in some cases. This is called a manual vacuum aspiration (MVA).
A few women develop an infection after having this operation. Prompt medical advice should be sought if there is a high temperature (fever), any offensive-smelling vaginal discharge or abdominal pains after a SMM. Any infection is usually treated successfully with antibiotics.
Many women and their partners find that miscarriage is distressing. Feelings of shock, grief, depression, guilt, loss and anger are common. It is best not to bottle up feelings but to discuss them as fully as possible with partner, friends, a healthcare professional or anyone else who can listen and understand.
As time goes on, the sense of loss usually becomes less. However, the time this takes varies greatly. Pangs of grief sometimes recur out of the blue. The time when the baby was due to be born may be particularly sad.
Further reading and references
Ectopic pregnancy and miscarriage: diagnosis and initial management; NICE Guidance (last updated November 2021)
Nanda K, Lopez LM, Grimes DA, et al; Expectant care versus surgical treatment for miscarriage. Cochrane Database Syst Rev. 2012 Mar 143:CD003518. doi: 10.1002/14651858.CD003518.pub3.
Sapra KJ, Joseph KS, Galea S, et al; Signs and Symptoms of Early Pregnancy Loss. Reprod Sci. 2017 Apr24(4):502-513. doi: 10.1177/1933719116654994. Epub 2016 Sep 27.
Miscarriage; NICE CKS, December 2022 (UK access only)