Other names :
Spontaneous abortion.
Introduction :
Failure of a pregnancy to progress beyond twenty weeks. Early Pregnancy period.
Cause :
A miscarriage occurs when a pregnancy fails to progress, due to the death of the foetus, or a developmental abnormality in the foetus or placenta. A few definitions are probably useful here. A foetus is the developing baby in the womb (uterus). The placenta (or afterbirth) takes nutrition from the mother, and passes it to the foetus through the umbilical cord. The cervix is the opening of the womb into the vagina. A pregnancy normally lasts for 40 weeks from the first day of the last menstrual period.
If the baby is lost before 20 weeks (early pregnancy), it is considered to be a miscarriage. After 20 weeks, doctors consider it to be a premature birth, although the chances of the baby surviving if born before 28 weeks, are very slim. Most miscarriages occur in the first twelve weeks of pregnancy. Many occur so early, that the woman may not even know that she has been pregnant, and may dismiss the problem as an abnormal period.
In more than half the cases, the miscarriage occurs because there is no baby developing. What develops in the womb can be considered to be just placenta, without the presence of a foetus (a blighted ovum is the technical term). There is obviously no point in continuing with this type of pregnancy, and the body rejects the growth in a miscarriage.
Some women do not secrete sufficient hormones from their ovaries to sustain a pregnancy, and this can also result in a miscarriage. These women can be given additional hormones in subsequent pregnancies to prevent a recurrence of the problem.
Malformations of the womb are another, though rarer, cause. This problem may be surgically corrected to prevent the cervix from opening prematurely, or to remove fibrous growths that may be distorting the womb. There are dozens of other reasons for a miscarriage, including stress (both mental and physical), other diseases of the mother (eg: diabetes, infections), injuries, and drugs taken in early pregnancy. Each case has to be considered individually.
Incidence :
Miscarriages are far more common than most women realise. Up to 15 percent of diagnosed pregnancies, and possibly 50 percent of all pregnancies, fail to reach 20 weeks.
Prevention :
Only if a specific cause for repeated miscarriages can be diagnosed can any preventative action be taken.
Investigations :
Those women who have repeated miscarriages will be thoroughly investigated by hormone assays, ultrasound scans and operations to inspect their reproductive parts.
Course :
One of the most emotionally traumatic experiences for a young woman is a miscarriage. A woman who is miscarrying develops abnormal bleeding during pregnancy, in association with pain low in the abdomen, and sometimes the passing of tissue. If any of these symptoms develop, a doctor should be consulted immediately.
Treatment :
There is virtually no treatment for a threatened miscarriage except strict rest, sedatives and pain relievers. If the body has decided to reject the foetus, medical science is normally helpless to prevent it. Once a miscarriage is inevitable, doctors usually perform a simple operation to clean out the womb, and ready it as soon as possible for the next pregnancy.
Complications :
Heavy bleeding, that may lead to anaemia, infections in the uterus, and the retention of some tissue in the uterus are the most common complications. Retained tissue may make it difficult for a further pregnancy to occur.
Outcome :
In most cases, there is no reason why a subsequent pregnancy should not be successful. It is only if a woman has two miscarriages in succession that doctors become concerned, and investigate the situation further.
Further information :
A miscarriage is very distressing to any woman, and they should receive as much support and reassurance as possible from family, friends and medical practitioners. SANDS (Stillbirth and Neonatal Death and Miscarriage Support) is a self-help group that operates in several states.
