A miscarriage happens when the fetus spontaneously dies and leaves the womb before week 24 of pregnancy: If a baby dies in the womb after week 24 it is referred to as stillbirth.
As early pregnancy testing has become both possible and increasingly accurate and early awareness of pregnancies has increased, it has become clear that early miscarriage is very common. The NHS estimates that as many as one in four pregnancies end in miscarriage, 80% of which take place in the first eight weeks: Research indicates that most women are likely to experience at least one miscarriage in their lifetime. Miscarriage may take place so early that a woman may not even have missed a period, or be aware that she is pregnant - particularly if she is not actively trying to conceive - and she may not even realise that she is miscarrying.
If you are aware of the pregnancy, however, then experiencing a miscarriage can be very traumatic, even in the very early days of pregnancy, and getting the support you need to see you through may not be easy. But the positive news is that the vast majority of those who do have a miscarriage will go on to experience a healthy pregnancy afterwards.
Miscarriage signs
The most usual signs of a miscarriage are heavy bleeding, perhaps with clots or tissue, and with strong abdominal cramps. The cramps are an indication that your uterus is contracting. You should contact your doctor right away, particularly if you are also feeling unwell and/or running a temperature, as these are signs of a possible infection.
If you experience very heavy vaginal bleeding then don't wait to see your doctor, go to your nearest A&E or call an ambulance if necessary.
If you have strong abdominal pain on one side then you should also seek medical advice as soon as possible, as this could be a sign of an ectopic pregnancy (where the embryo implants outside of the womb, usually in one of the fallopian tubes), which can be life-threatening for the mother.
For some women the first symptom of a miscarriage isn't bleeding, but simply losing the sensation of feeling pregnant with the disappearance of pregnancy signs.
Threatened miscarriage
If you experience bleeding during early pregnancy and your doctor diagnoses a threatened miscarriage, then don't panic, threatened miscarriage is simply the name given to unexplained vaginal bleeding in early pregnancy. Bleeding in early pregnancy is very common, it can happen any time in the first 24 weeks but it's most often seen in the first twelve weeks. Explained causes of bleeding in early pregnancy include implantation bleeding and hormonal bleeding, but when doctors can't give a reason for the bleeding then it's 'unexplained bleeding' or threatened miscarriage. When bleeding is light and isn't accompanied by painful abdominal cramping then it's most likely to be fine and the pregnancy will probably continue as normal. If bleeding is heavy and accompanied by pain then your chances of continuing the pregnancy are lower, but the bleeding doesn't necessarily mean that you'll suffer a miscarriage. Lighter period-like cramps are very common in early pregnancy and are a result of your uterus beginning to grow and stretch, so there's no need to worry about every twinge and ache.
Whenever you have any vaginal bleeding in pregnancy you should talk to your doctor as soon as possible, in most cases he or she will simply advise you to get plenty of rest, and with heavier bleeding s/he may tell you to get complete bed rest until the bleeding has stopped. You may be offered an early ultrasound scan to check whether the the baby is alright, or just told to wait and see.
What happens
If you miscarry before week nine of your pregnancy, which is when most miscarriages take place, you will usually fully miscarry within a week of the onset of bleeding and the miscarriage will be like a very heavy period, usually lasting up to ten days. Unless you have very heavy bleeding or one-sided abdominal pain you are unlikely to be admitted to hospital and will usually have to go through the experience at home. If you lose any blood clots or tissue then it's an unpleasant, but good idea to collect them in a sterile jar to show to your doctor.
Your doctor may conduct an internal examination to check your cervix. If your cervix has opened then a miscarriage is inevitable, even though it may not happen straight away.
If the bleeding has fully stopped within two weeks then the miscarriage is probably complete and you won't need any further treatment. However, it's important to be sure that there are no remnants of the pregnancy left in the womb, so you should have a check-up with your doctor, who may refer you for an ultrasound to confirm that the womb is empty.
If you experience a miscarriage after week nine, or you have prolonged bleeding (over 2 weeks), then the miscarriage may be 'incomplete', meaning that your uterus hasn't expelled all the pregnancy tissue. If your doctor suspects that the miscarriage is incomplete s/he will probably recommend that you go into hospital for a simple operation, called Dilation and Curettage, to ensure that the uterus is cleared of all the pregnancy tissue and so prevent infection. If you are diagnosed with an infection then you will be prescribed a course of antibiotics.
If a miscarriage takes place after months three or four it may be more like going through labour and you are more likely to be sent to hospital to deliver.
Missed miscarriage
Very rarely the fetus dies but the uterus doesn't expel the pregnancy tissue for some time, even as long as several weeks. This is known as a missed miscarriage and affects only 1% of pregnancies. Signs of a missed miscarriage might be the disappearance of pregnancy symptoms or a simple feeling that something is wrong. There may be no signs at all, and the miscarriage may be first picked up at a routine ultrasound or check.
If a missed miscarriage is diagnosed in the first three months of pregnancy you may have the choice of waiting for the miscarriage to complete on its own, or of having a dilation and curettage to remove the pregnancy tissue. For many women having the simple medical procedure is preferable to waiting for the miscarriage once they know that the fetus has died.
When a missed miscarriage occurs in later pregnancy the doctor may need to induce labour to remove the fetus, which will require a visit to hospital.
Causes of miscarriage
Genetic abnormalities
When a miscarriage occurs in the first three months of pregnancy, by far the most likely cause is chromosomal abnormality, a genetic problem. In these cases the body recognises that the pregnancy is unsustainable because of a problem with the fetus and so ends the pregnancy. The same problem is unlikely to occur again in future pregnancies. Because the quality of a woman's eggs is affected by age, the risk of miscarriage gradually rises as women become older.
Maternal problems and illnesses
A miscarriage may also be caused by hormonal imbalances, abnormalities of the womb or cervix, such as incompetent (weak) cervix, blood clotting disorders and maternal infections such as German Measles and Listeria.
External factors
External factors have been linked to an increased chance of miscarriage, including smoking (whether active or passive), excessive alcohol consumption, and very high caffeine consumption. In rare cases miscarriage may be caused by a severed fall or other accident. However, research has not shown any link between early miscarriage and lifting heavy loads, moderate exercise, stress or sex.
Will it happen again?
As we've said above, miscarriage is very common, and most women are likely to experience at least one miscarriage in their lifetime, even though they may not be aware of it happening at the time. If you experience a miscarriage your chances of having a second are not any higher for future pregnancies. If you have two miscarriages then your chances of a further miscarriage are slightly higher, however. Women who experience repeated miscarriage, which is termed as three or more consecutive miscarriages, may have a structural problem preventing the successful establishment of a pregnancy. It's usually only after two or three miscarriages that your doctor will look into the causes of the miscarriages - if not obvious - so that treatment can be recommended to prevent the problem recurring.
Sometimes a structural problem is evident with a first miscarriage, and if so, doctors may be able to make special recommendations or offer preventative treatment for subsequent pregnancies.
