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. Always tell your doctor 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?
Many women may have a small amount of bleeding (spotting) at the time of their missed period. This is sometimes called an 'implantation bleed'. It happens when the fertilised egg implants itself in the wall of your womb (uterus). It is harmless.
The most common cause of bleeding after the time of the missed period is miscarriage. Miscarriage is the loss of a pregnancy at any time up to the 24th week. A loss after this time is called a stillbirth. At least 8 miscarriages out of 10 actually 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.
How common is miscarriage?
Miscarriage accounts for over 40,000 hospital admissions in the UK each year. About 1 in 4 recognised pregnancies end in miscarriage. Far more pregnancies than this do not make it - as many as half. This is because in many cases a very early pregnancy ends before you miss a period and before you are even aware that you 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 that we inherit from our 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 mistake and rarely occurs again. Such genetic mistakes become more common when the mother is older - that is, over 35 years old. This means women aged over 35 years who are having children are more likely to have a miscarriage. This may also be why, if your partner is aged over 45 years, you are more likely to have a miscarriage, even if you are under 35 years old.
You are also at a greater risk of having a miscarriage if you:
- Smoke. The risk increases the more cigarettes you smoke.
- Drink too much alcohol. Even 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 your womb (uterus) or a weakness of the neck of your 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 unless you have three or more miscarriages in a row. This is because most women who miscarry will not miscarry again. Even two miscarriages are more likely to be due to chance than to some underlying cause. Even after three miscarriages in a row, more than seven women out of every ten will not have a miscarriage next time around.
Some myths about the cause of miscarriage
After a miscarriage it is common to feel guilty and to blame the miscarriage on something you have done, or failed to do. This is almost always not 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 also no proof that waiting for a certain length of time after a miscarriage improves your 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 that you are going to miscarry. Often the bleeding settles and the developing infant is healthy. This is called a threatened miscarriage. You do not usually 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 and lower tummy (abdominal) cramps. You may then pass something from the vagina, which often looks like a blood clot or clots. In many cases, the bleeding then gradually settles. 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.
In some cases of miscarriage, there are no symptoms. The baby stops developing or dies but it remains in the womb. You may have no pain or bleeding. You may no longer experience symptoms to suggest you are pregnant (for example, morning sickness or breast tenderness). This type of miscarriage may not be found until you have a routine ultrasound scan. This may be referred to by doctors as a missed miscarriage (also called early fetal demise, an empty sac or a blighted ovum).
The typical pain with a miscarriage is crampy lower tummy pain. If you have severe, sharp, or one-sided tummy pain, this 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 when you open your bowels. Sometimes there are no symptoms until you collapse because of heavy bleeding into the inside of your tummy (internal bleeding). This is called a ruptured ectopic pregnancy and is a potentially life-threatening situation that needs emergency surgery. You should call an ambulance or go to your nearest Accident and Emergency department if you are worried that you may have an ectopic pregnancy.
Do I need to go to hospital?
You should always report any bleeding in pregnancy to your doctor. It is important to get the correct diagnosis, as miscarriage is not the only cause of vaginal bleeding. However, if you are bleeding very heavily or have severe tummy (abdominal) pain when you are pregnant, call for an ambulance immediately.
Dr Sarah Jarvis, November 27th 2021
NICE guidance on miscarriage
The National Institute for Health and Care Excellence (NICE) has updated its recommendations on investigations and treatments in miscarriage. Your doctor will use this guidance to advise on next steps.
The first recommendation is for women who:
- Have a threatened miscarriage; and
- Have had an ultrasound scan which confirms the baby's heartbeat; and
- Have never had a miscarriage before.
If this applies to you, the new guidance recommends that you may not need to be referred straightaway for a scan. However, if your bleeding gets worse or goes on for at least two weeks, you should contact your doctor again. If your bleeding stops, you can continue routine antenatal care.
If you have a scan to confirm your pregnancy but have had a previous miscarriage, you should be offered vaginal progesterone pessaries to use until you have completed 16 weeks of pregnancy.
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 your local hospital. 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).
If it is unclear from your ultrasound scan whether the pregnancy is healthy or not then you may be asked to return for a repeat scan in one to two weeks.
Do I need any treatment?
Once the cause of bleeding is known, your doctor will advise on your treatment options.
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 your pregnancy are passed out naturally and the bleeding will stop within a few days after this, although can take up to 14 days to occur. However, if your bleeding worsens and becomes heavier or does not settle then you may be offered alternative treatment. Expectant management may not be offered if you have had a miscarriage in the past or if you have a bleeding disorder or any evidence of infection. You may decide that you would prefer to have a definitive treatment rather than taking this approach.
If your bleeding and pain settle then you should perform a pregnancy test after three weeks. If this is positive then you will need to see your doctor for an assessment.
Treatment with medicines
In some cases you may be offered what doctors call medical treatment for your miscarriage. That is, you may be offered a tablet to take either by mouth or to insert into your vagina. The medicine helps to empty your womb (uterus) and can have the same effect as an operation. You do not usually need to be admitted to hospital for this. Some women experience quite severe tummy (abdominal) cramps with this treatment.
You may 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.
You should perform a pregnancy test three weeks after receiving medical treatment. If this is positive then you will need to see your doctor for an assessment.
An operation may be offered to you, however, 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 it is likely you will be offered an operation. The operation most commonly performed to remove the remains of your pregnancy is called surgical management of miscarriage (SMM). In this operation, the neck of your womb (the cervix) is gently opened and a narrow suction tube is placed into your womb to remove the remains of your 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). Your doctor will be able to discuss the procedure in more detail with you.
A few women develop an infection after having this operation. If you experience a high temperature (fever), any offensive-smelling vaginal discharge or abdominal pains then you should see a doctor promptly. 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 your partner, friends, a doctor or midwife, 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)
Miscarriage; NICE CKS, May 2018 (UK access only)
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.