About 1 in 7 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. Losing a pregnancy can be hard for both partners. However, most women who have a miscarriage go on to have a successful pregnancy next time.
What is a 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.
Note: in the past, medical information has sometimes referred to a miscarriage as a spontaneous abortion. This can be upsetting, as in usual language the word abortion is used to mean a procedure to end a pregnancy.
How common is miscarriage?
Early pregnancy loss accounts for over 50,000 admissions in the UK each year. About 1 in 7 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 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.
What causes miscarriage?
It is thought that most early miscarriages are caused by a one-off chromosomal fault. This is usually an isolated genetic 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.
You are at a greater risk of having a miscarriage if you:
- Smoke. Smoking more than 14 cigarettes per day doubles the risk compared with non-smokers.
- 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.
- Are overweight or obese. If you are overweight, you may be able to reduce your chances of having a miscarriage if you lose weight before you try to get pregnant.
- Have any abnormalities of your womb (uterus) or a weakness of the neck of your womb (the cervix).
- Have certain medical conditions (eg, systemic lupus erythematosus, antiphospholipid syndrome).
- Have diabetes mellitus that is not well controlled.
There are other less common causes of miscarriage. These include: hormonal imbalance, abnormalities of the womb, weakness of the cervix and certain infections like listeria and German measles (rubella). Alcohol abuse, cigarette smoking, illicit drug use and obesity may also increase the risk of miscarriage.
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.
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, constipation, straining at the toilet, stress, worry, sex, eating spicy foods or 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 sometime in the first 12 weeks of pregnancy. This does not always mean that you are going to miscarry. Often the bleeding settles and the growing baby 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 some tissue 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 severe in some cases.
In some cases of miscarriage, there are no symptoms. The fetus stops developing or dies but it remains in the womb (uterus). 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.
Some women may experience some mild bleeding but not have any pain (or only a little amount of pain). The pregnancy then progresses normally thereafter. This is called a threatened miscarriage.
The typical pain with a miscarriage is crampy lower abdominal pain. If you have severe, sharp, or one-sided abdominal pain, this may suggest ectopic pregnancy. This is a pregnancy that develops outside the womb. There may be very little blood lost, or the blood may look almost black. A ruptured ectopic pregnancy 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 bleed heavily or have severe tummy (abdominal) pain when you are pregnant, call for an ambulance immediately.
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 - no pregnancy inside the womb).
If it is unclear from your ultrasound scan whether the pregnancy is viable 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.
Many women now opt to 'let nature take its course'. In most cases the pregnancy tissue is passed out naturally and the bleeding will stop within a few days after this. This can take up to 14 days to occur. This is not usually offered if you have had a miscarriage in the past or if you have a bleeding disorder or any evidence of infection. However, if your bleeding worsens and becomes heavier or does not settle then you may be offered alternative treatment. Alternatively, 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 medication to take either by mouth or to insert into your vagina. The medication 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.
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 postiive then you will need to see your doctor for an assessment.
An operation may be offered to you though 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 evacuation of retained products of conception (ERPC). 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 remaining pregnancy tissue. This operation takes around 10 minutes.
This may be performed without the need for a general aneasthetic in some cases. 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 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 husbands or partners, friends, with a doctor or midwife, or with someone 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 & references
- Satpathy HK, Fleming A, Frey D, et al; Maternal obesity and pregnancy. Postgrad Med. 2008 Sep 15;120(3):E01-9.
- Diagnosis and initial management in early pregnancy of ectopic pregnancy and miscarriage; NICE clinical guideline (Dec 2012)
- Andersen AM, Andersen PK, Olsen J, et al; Moderate alcohol intake during pregnancy and risk of fetal death. Int J Epidemiol. 2012 Apr;41(2):405-13. doi: 10.1093/ije/dyr189. Epub 2012 Jan 9.
- Bhattacharya S, Smith N; Pregnancy following miscarriage: what is the optimum interpregnancy interval? Womens Health (Lond Engl). 2011 Mar;7(2):139-41.
|Original Author: Dr Tim Kenny||Current Version: Dr Louise Newson||Peer Reviewer: Dr John Cox|
|Last Checked: 11/02/2013||Document ID: 4300 Version: 40||© EMIS|
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