Spontaneous miscarriage is defined as the loss of a pregnancy before 20 weeks gestation. Vaginal bleeding is the most common symptom of a threatened miscarriage, but not all women who experience bleeding will miscarry. The cause of miscarriage is usually not found. Women who have had three consecutive (recurrent) miscarriages are at risk of miscarrying again.
Spontaneous miscarriage is defined as the loss of a pregnancy before 20 weeks gestation. Most spontaneous miscarriages (75 to 80 per cent) occur in the first 12 weeks of pregnancy. It is estimated that one in four pregnancies end in miscarriage. Many miscarriages are unreported or go unrecognised because they occur very early in the pregnancy.
Causes of a miscarriage
A miscarriage usually occurs because the pregnancy is not developing properly. The development of a baby from a female and a male cell is a very complicated process. If something goes wrong with the process, the pregnancy will stop developing. Miscarriages are more common in older women than younger women, largely because chromosomal abnormalities are more common with increasing age.
Another cause of miscarriage may be that the developing pregnancy did not embed itself properly into the lining of the uterus (womb). The natural reaction of the uterus is to expel the non-viable pregnancy.
Symptoms of a miscarriage
Pain and bleeding in early pregnancy can mean that you are having a miscarriage, but not always. Bleeding is very common in early pregnancy, affecting about one in four women, many of whom will go on to have a healthy baby. Early bleeding that does not lead to miscarriage will not have caused your baby any harm.
If the bleeding is being caused by a miscarriage, there is no treatment or therapy that can stop the miscarriage from occurring. However, it is still very important that you see a health professional.
Treatment for a miscarriage
Unfortunately nothing can be done to stop a miscarriage once it has begun. Treatment is aimed at avoiding heavy bleeding and infection. It is also aimed at looking after you, physically and emotionally.
You may need to wait a short period of time before treatments begin. If you experience heavy bleeding with clots and crampy pain in that time, it is likely that you are passing the pregnancy tissue. The bleeding, clots and pain will usually settle when most of the pregnancy tissue has been passed. Sometimes, the bleeding will continue to be heavy and you may need further treatment. If you think you are having, or have had, a miscarriage, you should see a doctor or go to an emergency department.
You should go to your nearest emergency department if you have:
- Increased bleeding – for instance, soaking two pads per hour or passing golf ball-sized clots
- Severe abdominal pain or shoulder pain
- Fever or chills
- Dizziness or fainting
- Vaginal discharge that smells unpleasant
- Diarrhoea or pain when you open your bowels.
Types of miscarriage
The types of miscarriage that can occur include:
- Missed abortion– occurs when the pregnancy has failed, although there has not been any bleeding or other signs. Occasionally, the aborted pregnancy may remain in the uterus for weeks or even months until bleeding commences. Missed abortion is suspected when pregnancy symptoms disappear and the uterus stops growing. It is diagnosed by an ultrasound examination.
- Blighted ovum– this occurs when a pregnancy sac is formed, but there is no developing baby within the sac. This is diagnosed by ultrasound, usually after some bleeding.
- Ectopic pregnancy– this occurs when the developing pregnancy implants in the fallopian tubes rather than in the uterus. One to two per cent of all pregnancies are ectopic and without treatment, an ectopic pregnancy can seriously impact on your health and fertility.
Reactions to miscarriage
There is no ‘right way’ to feel after a miscarriage. A range of feelings is normal, and they often linger for some time after the miscarriage. Reactions may include feelings of:
- Anger and disbelief
- Sadness and a sense of isolation.
Some degree of grief is very common, even if the pregnancy wasn’t planned. Partners may react quite differently, just as people can respond differently to a continuing pregnancy. Try to take it a day at a time and acknowledge your feelings and reactions as they arise.
In addition to the grief you may feel, your body will be undergoing many hormonal changes, which may make you feel very emotional. Family or close friends can be a great source of support at these times. Alternatively, you may choose to seek professional support.
Don’t blame yourself for a miscarriage
Pathology tests are sometimes performed after a miscarriage, but usually, no cause can be identified. This can add to feelings of distress and disbelief, and may lead to feelings of guilt. However, doctors agree that a miscarriage is rarely caused by anything the mother did – or didn’t – do (for example, drank a glass of wine, ate a particular food, had sex or did not rest enough). In the majority of cases, the next pregnancy proceeds to full term.
After a miscarriage
Often, some of the pregnancy tissue remains in the uterus after a miscarriage. If it is not removed by scraping the uterus with a curette (a spoon-shaped instrument), you may bleed for a long time or develop an infection. Unless all the pregnancy tissue has been passed, your doctor will usually recommend that a curette (also called a ‘D&C’ – dilation and curettage) be performed. This is done under a light general anaesthetic and you can usually go home later the same day. A sample of tissue is usually sent for pathology tests.
After the curette
Most women bleed for five to 10 days following a curette. Contact your doctor if you experience:
- Prolonged or heavy bleeding
- Blood clots or strong abdominal pain
- Changes in your vaginal discharge
- Fever or flu-like symptoms.
Your next period after a miscarriage
Your ovaries will usually produce an egg about two weeks after your miscarriage. Your first period should occur within four to six weeks. You should have a check-up with your doctor six weeks after your miscarriage to make sure there are no problems and to ensure your uterus has returned to normal size. You can also ask any questions about your miscarriage at this time, including the results of any pathology tests.
The effect of miscarriage on future pregnancies
Most of the problems that cause miscarriage happen by chance and are not likely to happen again. One miscarriage does not significantly increase the risk of the same thing happening with your next pregnancy, as long as no specific cause has been found. Testing is not usually offered to women who have miscarried once or twice because it is very unlikely that anything would be found.
However, women who have had three consecutive miscarriages are at risk of miscarrying again. If you fall into this category, you can attend the Recurrent Miscarriage Clinic at The Royal Women’s Hospital for further investigations, counselling and management of future pregnancies.
Trying for another pregnancy after miscarriage
There is no right time to try for another pregnancy. Some couples decide they need time to adjust to their loss, while others want to try again right away. It is usually suggested you wait until after your next period before trying again. As it is possible to become pregnant again straight away, it is important to use contraception until you are ready to try again.
If you are Rh (Rhesus) negative
If you have an Rh negative blood group, you will require an injection of anti-D immunoglobulin following a miscarriage. This will prevent problems with the Rh factor in future pregnancies. Your doctor will discuss this with you further.
Preparing for another pregnancy after a miscarriage
Although the common reasons for miscarriage cannot be prevented, you can improve your chances for long-term fertility and a successful pregnancy by:
- Stopping smoking
- Taking regular exercise and having a balanced diet
- Reducing stress
- Maintaining your weight within recommended limits.
Take folic acid
It is recommended that all women planning a pregnancy take folic acid as it helps promote the normal development of a baby’s nervous system. You will need to take 0.5 mg per day for one month prior to pregnancy and up to 12 weeks gestation.