Characterized by high blood pressure and protein in the urine, preeclampsia is a condition that, if allowed to develop into full-blown eclampsia, can have implications for you and your baby.
Preeclampsia occurs in about one in 14 pregnancies and usually some time after the 20th week. Its severity varies, but the more severe the condition becomes, the greater the risk of complications.
The condition is especially characterized by high blood pressure. When your blood pressure becomes too high, the amount of blood your body delivers to the developing fetus fails and an undernourished fetus can fail to grow normally. As a result, your baby may be unusually small – a condition known as intra-uterine growth retardation (IUGR). Normal blood pressure in a healthy (pregnant or otherwise) woman is around (or ideally just below) a reading of 120/80mmHg. The upper number is your systolic blood pressure, the most pressure your blood is under during a heartbeat, when your heart is pumping hardest; the lower number is your diastolic blood pressure, the least pressure your blood is under when your heart is at rest, during a heartbeat. The blood-pressure reading is taken in millimeters of mercury (mmHg).
Preeclampsia is classed as mild or severe. In mild preeclampsia, your blood pressure reading will probably be around 140/100mmHg and accompanied by slight swelling in your hands and feet, but no detectable protein in your urine. In severe preeclampsia, your blood pressure can rise much higher, to around 160/110mmHg, and your urine sample will show traces of protein because yoru kidneys are struggling to function properly. These symptoms, as well those given opposite, indicate that your preeclampsia is severe and you need urgent medical treatment.
Occasionally preeclampsia develops very quickly, so don’t hesitate to call your doctor or midwife if you have any of the following symptoms in the second half of your pregnancy (or in the first few days after you’ve had your baby, as preeclampsia is still a risk up to four weeks after the birth); rapid weight gain or sudden swelling in your ankles or face; blurred vision; decreased urine output; headaches; confusion or anxiety; shortness of breath on exertion; nausea or vomiting; and pain in the top of your abdomen.
No one really knows what causes preeclampsia, although some believe it may be a malfunction in the placenta. You’re at greater risk of the condition if you fall into any of the following categories. If this is your first pregnancy; if you’re carrying multiple babies (such as twins or triplets); if you have pre-existing high blood pressure (hypertension), diabetes mellitus, kidney disease, connective tissue disease or vascular disease; if you’re under 25 or over 35; if you’re overweight or obese; or if you or members of your family have had preeclampsia or eclampsia. However, please rest assured that stress, worry, and working during pregnancy will not cause preeclampsia and there’s no reason not to live a normal life while you’re pregnant.
Around one in five women with severe preeclampsia develop hemolysis, elevated liver enzymes and low platelets (HELLP) syndrome. This basically means that blood cells start to break down and your liver stops functioning effectively, which in turn increases your risk of serious bleeding.
However, most serious of all is when preeclampsia deteriorates into a life-threatening condition called eclampsia. About one in a hundred women with preeclampsia develops eclampsia, which is associated with convulsive seizures and coma (in the mother). It’s estimated that approximately 150 women and 1,200 babies in the USA and approximately ten women and several hundred babies in the UK die each year from the complications of severe preeclampsia. The main aim of any treatment program for a woman with preeclampsia, therefore, is to prevent eclampsia. Happily, we are able to diagnose and manage preeclampsia so effectively that eclampsia is now a rare condition.