Pre-eclampsia is a common complication of pregnancy that causes high blood pressure and may lead to a number of serious problems including convulsions (eclampsia) and kidney failure.
What is pre-eclampsia
Pre-eclampsia is a common complication of pregnancy that causes high blood pressure (over 140/90). It often causes leakage of protein in the urine, and excessive swelling of the legs, hands and face. It can also affect almost any organ in the body, but doesn’t always do so. It only occurs in the last half of the pregnancy or in the first few days after the baby is delivered. It always resolves within a few days to weeks after delivery of the baby, and ultimately almost all mothers and babies do well.
It is not known why some women develop pre-eclampsia, although some factors make development of the disease more likely (such as first pregnancy, family history of pre-eclampsia, pre-existing high blood pressure, multiple pregnancy). There is no test that will predict who will get the disease, and no way to prevent it.
Pre-eclampsia is sometimes called by other names, including ‘toxaemia’, ‘pregnancy-induced hypertension’, and ‘pre-eclamptic toxaemia’.
Pre-eclampsia can be mild or severe. It is called ‘eclampsia’ if a seizure occurs. One severe form of the disease is called “HELLP” syndrome if a particular combination of problems develops (Haemolysis, Elevated Liver enzymes, Low Platelets). Haemolysis is excessive auto-destruction of red cells in the blood.
How does pre-eclampsia cause these problems?
The body’s arteries are surrounded by muscle that is normally relaxed to allow blood to flow easily to all the organs in the body, and thus supply oxygen and nutrients to those organs. During pre-eclampsia, there is constriction of the muscles around the small arteries that then damages the internal lining of the arteries (‘endothelium’) and the red cells in the blood as they try to squeeze through the constrictions. Ultimately the constrictions cause high blood pressure and reduced blood flow to the liver, kidneys, eyes and brain. When the internal lining of the blood vessels is damaged, fluid can leak out into the tissues, causing the swelling of the legs, hands and face.
Does pre-eclampsia affect the baby?
Arteries carrying blood to the baby are also affected. If the process is severe enough, the baby’s growth can slow down, the amount of fluid surrounding the baby can decease, and there is increased risk of placental separation from the uterus and bleeding (‘abruption’). All of these things are harmful to the baby. A premature delivery is required if the pre-eclampsia is severe, before the mother or baby are harmed. The baby is monitored regularly before delivery to assess its health and evaluate the effect of the pre-eclampsia, by measuring the baby’s heartbeat and using ultrasound.
What is the treatment for pre-eclampsia?
There is no treatment except delivery of the baby. The mother’s blood pressure needs to be lowered to reduce the risk of having a stroke, but lowering the blood pressure does not reduce the artery constrictions, and thus does not change the course of the pre-eclampsia by itself. Several drugs can be used safely to lower the blood pressure (for example, labetalol, hydralazine, nifedipine, methyl-dopa).
Seizures occur in 1% of women with pre-eclampsia if they are not given any medication to prevent them. Signs and symptoms that sometimes precede seizures include very brisk reflexes, persistent visual disturbances or persistent headaches. Giving magnesium intravenously reduces the risk of seizures.
The swelling is uncomfortable but not harmful, and will resolve by itself. Losing protein in the urine does not damage the kidney.
Why does my relative need to go to intensive care?
Women with severe pre-eclampsia or eclampsia generally come to the Intensive Care after delivery of the baby to continue intravenous treatment with the magnesium and drugs to lower the blood pressure. If a mother has developed kidney failure or fluid in the lungs, she may need to come to the Intensive Care before the baby is delivered.
What Happens in Intensive Care?
Frequent nursing and medical observations are required to ensure control of the blood pressure and reduce the risk of seizures. A bedside monitor will be used to closely monitor blood pressure and an indwelling urinary catheter inserted to measure urine output. The mother’s blood and urine are tested frequently to check liver and kidney function, platelet count and for red cell destruction (‘haemolysis’).
Depending upon the condition of the baby and the mother efforts will be made to bring the two together. The baby will be kept in a nursery appropriate for their condition. In most cases the father and other relatives will be encouraged to be involved with the care of the baby by maternity staff. Breastfeeding will be facilitated by both the ICU and maternity staff if this is what the mother wishes.
How long will the patient remain in Intensive Care?
A mother will generally leave the Intensive Care and go to the post-natal ward when she no longer requires the magnesium infusion (1-2 days after the delivery) and the raised blood pressure is easily controlled with tablets.
The information contained in this sheet is general in nature and therefore cannot reflect individual patient variation. It is meant as a back up to specific information which will be discussed with you by the Doctors and Nurses caring for your loved one. ICCMU attests to the accuracy of the information contained here BUT takes no responsibility for how it may apply to an individual patient. Please refer to the Disclaimer.
- First publishing December 2005
- Written by Dr Louise Cole Staff Specialist ICU, Nepean Hospital, Penrith NSW, Australia.
- Edited by Kaye Rolls Clinical Project Officer, ICCMU NSWHealth and CWPWP.