Important: This is intended as general information only. It may not apply to your specific situation. It is not a substitute for medical advice. If you have a question or concern, please raise it with me at your next appointment or contact me sooner if it's urgent.
Preeclampsia is a disease that only occurs in pregnancy and can only be cured by delivery. It can affect various different organ systems in the mother and can affect the function of the placenta which can, in turn, affect the baby. It varies in severity from a very mild condition to a severe, life-threatening illness. It affects about 10% of pregnancies and is most common in first pregnancies.
Although preeclampsia can affect the mother in various ways, the most common sign is high blood pressure. Other features may include increased swelling, the presence of protein in the urine and blood test evidence of changes in the liver, kidneys and clotting system. Women with preeclampsia may develop headaches, abdominal pain, nausea and vomiting and changes in their vision. Looking at this list of symptoms, you may notice that some of them are common symptoms in pregnancy. Not all headaches are due to preeclampsia – in fact, most are not. Equally, not everyone with preeclampsia will experience all these changes.
If preeclampsia affects the function of the placenta, this can affect the amount of oxygen and nutrients the baby receives. This may affect the baby’s growth and, in severe cases, be acutely dangerous to the baby.
All of this may sound scary (and certainly, preeclampsia can be scary) but it is important to remember that preeclampsia, for many women, is a mild condition requiring a bit of extra monitoring and minimal intervention. Of the 10% of women who get preeclampsia, only 10% of them (so 1% overall) get a severe version of the disease.
What happens if you have high blood pressure in the rooms?
Every time you come to see me in the rooms I will check your blood pressure. We will start this from your very first visit although it is unusual to develop preeclampsia before 28 weeks gestation. If your blood pressure is high, the first thing I will do is repeat the measurement after you have rested for a while – sometimes the stress of getting to your appointment is enough to temporarily raise your blood pressure. If, however, your blood pressure remains high, I will then check a urine sample to see if there is any protein leaking from your kidneys and examine you looking for any other signs such as increased reflexes. I will then usually arrange some blood tests looking for any other abnormalities. The next step will depend on what all these tests show. In very severe cases, delivery may be recommended. Usually, however, this is not necessary immediately and we embark on a program of monitoring of both you and baby. This is to ensure that it safe to continue the pregnancy.
Monitoring of the mother
Monitoring the mother usually takes the form of regular visits to the rooms to check your blood pressure and urine. We may also perform regular blood tests to monitor your liver, kidneys and blood clotting.
Monitoring of the baby
Monitoring of the baby usually starts with a cardiotocograph (CTG) which is a tracing of the baby’s heart rate. This gives us an idea of how healthy the baby is at that time. We may also use ultrasound to assess the growth and wellbeing of the baby.
Treatment of preeclampsia
The only way to ‘cure’ preeclampsia is by delivery. However, in mild cases, this may not be necessary. In cases of early preeclampsia, where the baby is still very premature, we may wish to delay delivery as long as we safely can to allow the baby a little more time to develop in utero. This can become a delicate balance between the risks of delivering a premature baby and the risks to the baby or the mother of continuing the pregnancy. This is why there is so much monitoring – we need to get a clear idea of how well the mother and the baby are doing to make this decision. It’s important to bear in mind that some premature babies are better off out of the uterus if the environment in the uterus becomes unfavourable.
We sometimes use antihypertensive (blood pressure lowering) medications in pregnancy in order to protect the mother from the effects of severe high blood pressure. While this is, in some cases, an important and necessary treatment, it doesn’t actually fix the underlying disease process.
The balance between the advantages of a bit more time for the baby in utero and the potential benefit to the mother or baby of delivery will vary depending on the baby’s gestation. For example, we may tolerate a bit more risk in order to get a baby from 28 weeks to 30 weeks gestation, as this difference is significant. We would tolerate much less risk, however, with a 38 week pregnancy as the benefit to the baby in getting another two weeks in utero is minimal. If we are planning to deliver a baby at less than 34 weeks gestation, we usually give the mother an injection of corticosteroids. These drugs cross the placenta and help the baby’s lungs mature.
The mode of delivery (induction of labour or caesarean section) will depend on the situation and the health of both the mother and the baby. Needless to say, whichever mode is chosen, we monitor both very carefully.
Magnesium Sulphate is sometimes given to women with preeclampsia around the time of delivery. This is to prevent one of the more severe complications of preeclampsia – eclampsia. This is when a women develops generalized seizures (fits) and usually happens in conjunction with severe preeclampsia. Fortunately, it is rare and, if it occurs, treatable. However, prevention is better than treatment and I will suggest an infusion of magnesium sulphate if I think you are at risk.
The signs and symptoms of preeclampsia may take some time (usually several days, rarely several weeks) to resolve after delivery and monitoring and treatment will continue in this time as required.
All of this may sound scary. Remember, severe preeclampsia is rare and even women who develop high blood pressure are unlikely to be at the scarier end of this spectrum. If your blood pressure is raised, I will discuss the situation with you in detail and make sure you understand the results of all your tests monitoring and any plans for the rest of the pregnancy.
Most cases of preeclampsia occur in first pregnancies. If it does recur in subsequent pregnancies, it tends to be later in the pregnancy and less severe. There is a small group of women who are at risk of recurrent, severe preeclampsia. This includes women with underlying medical problems and women who have previously experienced severe, early preeclampsia. If you have had preeclampsia, I will talk to you about your risk of recurrence and, if you are in this high risk group, about what we can do to reduce your risk in subsequent pregnancies.