What is a Miscarriage?
A miscarriage is the spontaneous loss of a baby prior to the 20th week of a pregnancy.
It is thought as many as 50 percent of all pregnancies end in miscarriage. The exact figures are hard to determine as many women lose a baby before they know they are pregnant.
Between 10 and 15 percent of women who have established they are pregnant will experience a miscarriage. Many happen before the 12th week (first trimester). Between one and five percent will occur from weeks 13 to 19 (second trimester). (1)
Symptoms
In most miscarriages, the exact cause will not be known. There are, however, some factors which can contribute to the likelihood of miscarriage.
Chromosomes
Many miscarriages, about fifty percent, are as a result of a chromosome abnormality. A chromosome is the part of a cell that contains genes. There are 23 pairs of chromosomes in every person, making a total of 46. For every pair, one chromosome comes from the father and one from the mother.
When a chromosome in the fetus is abnormal, miscarriage can happen. Some chromosome problems include:
When an embryo does not develop into a baby after implantation in the uterus, miscarriage can happen (blighted ovum).
An embryo can stop developing in the uterus and dies (intrauterine fetal demise).
The uterus sometimes forms a tumor at the start of a pregnancy. It happens when the chromosomes are not correct in an embryo and the placenta does not form properly (molar pregnancy).
Part of a chromosome might rearrange itself and join with a different chromosome (translocation). (2)
Cervical and Uterine Issues
Some problems which affect the cervix and uterus can lead to miscarriage.
Sometimes a band of tissue or muscle is present which divides the uterus into two parts (separate uterus). Scar tissue and fibroids are two other factors affecting the uterus which can prevent a viable pregnancy. These can be corrected surgically prior to trying conceive a baby.
If the cervix is what is classed as insufficient, it opens too early in a pregnancy, allowing a miscarriage. This can happen with or without contractions. A stitch can be put into the cervix to keep it closed. (3)
Infections
Some infections, such as sexually transmitted diseases and food poisoning (listeriosis), can lead to miscarriage. (4)
Risk Factors
There are risk factors which might result in a miscarriage. Hormonal issues or health problems like diabetes, autoimmune disorders, thyroid function and obesity can contribute.
Lifestyle choices such as smoking, malnutrition, drug use, excessive alcohol consumption, and too much caffeine can also play a part.
Age might also predispose a woman to the likelihood of miscarriage. Women between 35 and 45 have between a 20 and 35 percent of miscarriage. Over the age of 45 this increases to a 50 percent chance. (5)
Symptoms of Miscarriage
If a woman experiences any of the signs and symptoms of a miscarriage they should see a medical professional. These include:
Back Pain
Some back pain is common during pregnancy. However, if its onset is sudden, becomes increasingly severe, or is accompanied by rhythmic cramps, it is a cause for concern.
One way of assessing this is to compare it to menstrual pains, if it is associated with miscarriage it will generally be worse. (6, 7)
Bleeding
Up to 30 percent of women will experience some bleeding in early pregnancy. About 50 percent of the time this will result in a normal full term pregnancy.
Seeing brown or bright red blood, sometimes accompanied by cramps, could be a sign of a miscarriage. (8)
Vaginal Discharge
vaginal discharge, characterized by mucus that is pinkish-white in color, or clots of tissue-like material discharging from the vagina, are a symptom of miscarriage. (9)
Contractions
A contraction happens when the muscles in the uterus contract and release. They cause a cramping feeling which can be very painful. They are usually rhythmic, happening between every five to 20 minutes.
This pain is usually experienced in the lower tummy and back. (10)
Decrease in Pregnancy Signs
Some of the signs of early pregnancy include breast tenderness, nausea and sickness. If these signs have been present and suddenly stop, it could indicate a miscarriage. (11)
Stages
There are no stages of miscarriage, there are however different types, which include:
Threatened Miscarriage
This type of miscarriage happens when your body indicates some signs of the condition. Vaginal bleeding and lower abdominal pain might be present which can last for a few days or several weeks. The cervix, however, remains closed.
These symptoms may pass and the pregnancy is likely to continue normally. But they could worsen and result in a miscarriage.
Inevitable Miscarriage
This can happen following a threatened miscarriage, or happen spontaneously. Vaginal bleeding will be profuse and cramps in the abdomen quite strong. The neck of the cervix will be open and miscarriage cannot be prevented. The fetus will be lost along with the blood.
If the bleeding and cramps continue the miscarriage might not be complete.
Complete Miscarriage
When all the pregnancy tissue has left the uterus, the miscarriage is classed as complete. Bleeding and cramps might continue for several days.
If this has happened at home or elsewhere, without medical assistance, a check-up should be carried out by a midwife or doctor.
Missed Miscarriage
There are times when a baby dies but remains in the uterus. This is classed as a missed miscarriage. Signs this may have happened include brownish discharge and the absence of pregnancy symptoms, such nausea and breast tenderness.
An ultrasound scan can detect this by revealing a lack of fetal heartbeat.
Recurrent Miscarriage
More than three miscarriages in a row are classed as recurrent. This occurs in about one percent of first trimester pregnancies. (12, 13)
Other Causes of Pregnancy Loss
Ectopic Pregnancy
Another cause of pregnancy loss is an ectopic pregnancy. This happens when an embryo becomes implanted outside the uterus, usually in a fallopian tube.
The signs of this include: bleeding, severe lower abdominal pain, vomiting or pain in the tip of a shoulder. If these symptoms are experienced, emergency medical care is necessary.
A fetus cannot generally survive an ectopic pregnancy.
Molar Pregnancy
This type of pregnancy has failed to develop normally from conception. Surgical intervention is necessary to remove the embryo.
Blighted Ovum
Also known as an anembryonic pregnancy, an ovum sac develops but there is no embryo inside it. It indicates that a baby was conceived but reabsorbed by the uterus early in pregnancy. (14)
Treatment
Once a miscarriage has started, nothing can be done to prevent it. There are options available in respect of what happens next.
Expectant Management
This could be recommended when a miscarriage happens early in the pregnancy. Sometimes referred to as a “wait and watch” approach, a woman would go home and wait until all the pregnancy tissue leaves the body.
This could be very quick or it could take a few weeks.
Medical Management
There are medications which can help speed the process of pregnancy tissue leaving the body. These are generally administered in a hospital and you might be required to stay in hospital.
Surgical Management
If bleeding associated with a miscarriage is heavy, or there are signs of infection or significant pain, surgical intervention may be recommended. Surgery could also be considered if medical management or expectant management have not been successful.
The procedure carried out is a dilation and curettage (D&C). It involves using suction to remove the remaining pregnancy tissue from the uterus. This minor surgery can be performed under local or general anesthetic.
Counselling and/or support might be offered to help individuals or couples cope with the emotional effects of a miscarriage. (15)
FAQ
What is a miscarriage? A miscarriage is the spontaneous loss of a baby prior to the 20th week of a pregnancy.
What are the signs of a miscarriage? Signs of this condition include vaginal bleeding and/or discharge, stomach and back pains or rhythmic cramps.
How do you develop a miscarriage? The cause of many miscarriages is unknown. There could be chromosome abnormalities, lifestyle factors, maternal illnesses, uterine or cervical issues which contribute.
How are you diagnosed for a miscarriage? An ultrasound scan can detect a miscarriage.
What is the best treatment for a miscarriage? A miscarriage cannot be prevented once it takes place. There are treatments which help ensure all pregnancy tissue has left the body.
What are the long term complications of a miscarriage? Most women who experience a miscarriage have subsequent successful pregnancies. If miscarriages are recurrent, tests are likely to be carried out to investigate the cause. (16)
Is a miscarriage considered a disability? A miscarriage is not considered a disability.
Is there a cure for a miscarriage? Unfortunately, a miscarriage cannot be prevented once it has started.
Is a miscarriage life threatening? A miscarriage is not considered life threatening.
Summary
A miscarriage is the spontaneous loss of a baby prior to the 20th week of a pregnancy which once started, cannot be prevented.
The exact cause of the majority of miscarriages is unknown. However, if no other factors are involved, e.g. injury or accident, it is thought a miscarriage is associated with abnormalities in the embryo in early pregnancy.
Fortunately, the majority of women who experience a miscarriage will go on to have a successful pregnancy.