Professor and Head, Department of Obstetrics and Gynaecology, School of Medicine and Pharmacy, University Hospital, Vrije Universiteit Brussel, Brussels
What is pre-eclampsia and eclampsia?
Pre-eclampsia and eclampsia are conditions associated with high blood pressure, loss of protein in the urine and swelling of the body that occur during pregnancy. Pre-eclampsia is also called toxaemia of pregnancy, which may develop into eclampsia if it is complicated by fits. These conditions usually develop in the second half of pregnancy though sometimes they develop shortly after birth.
What are the causes?
The exact cause of this problem is not known. The disorder is at any rate triggered by one or more substances produced by the placenta (the afterbirth), which induce a generalised reaction in the pregnant woman. One of the main features of this reaction is a constriction of the small arteries of the body.
What are the symptoms?
Rapid weight gain
Swelling of the feet, ankles, hands and face
Headache and dizziness
Ringing in the ears
Decreased production of urine
Nausea and vomiting
A state of confusion.
Who is at greater risk?
Women who are pregnant for the first time
Women who have a family history of such a problem
Women who are 40 years old or more
Women with pre-existing high blood pressure
Women expecting twins or triplets.
What are the complications associated with the problem?
A very high blood pressure interferes with the placenta's ability to transfer oxygen and nutrients to the baby resulting in a low birth weight baby with other developmental problems.
Very high blood pressure can cause malfunctioning of the kidneys.
There can be destruction of the red blood cells, disturbed liver function and a decrease in the number of platelets (blood cells that play a key role in the clotting process). A decreased platelet count can lead to uncontrollable bleeding during delivery .
If the blood pressure is not kept under control it can lead to eclampsia wherein the woman develops fits leading to a decreased supply of oxygen to the baby. The placenta (the afterbirth) may also start to separate from the wall of the uterus.
How is it diagnosed?
A woman's blood pressure is always measured at every visit to the doctor and a record is maintained. If the diastolic (lower reading) blood pressure is found to be high (95mmHg or more instead of the normal 80mmHg) and the systolic (upper reading, 150-160 mmHg instead of the normal 120 mmHg) or if there is protein in the urine as diagnosed by urine examination , the condition is called pre-eclampsia.
What is the treatment?
The treatment of pre-eclampsia is bed rest and as soon as the foetus has a good chance of survival outside the womb the doctor should decide on delivery. Careful monitoring of blood pressure, weight and urine checks for protein are needed. Delivery can be induced in the following instances:
The diastolic blood pressure increases from 80mmHg (normal) to 100 or 110mmHg consistently for a 24-hour period.
Persistent or severe headache.
Pain in the abdomen.
Abnormal liver functions as diagnosed by the tests.
Abnormal fetal heart rate.
How can it be prevented?
There are no known preventive methods for this condition. An early diagnosis through regular visits to the doctor during pregnancy thus becomes important.
Taking a calcium tablet daily in pregnancy may possibly somewhat decrease the risk of developing these disorders.