For the majority of women, pregnancy is a problem-free experience, although those so-called "minor ailments" such as morning sickness, backache and heartburn can be hard to deal with. Throughout pregnancy you'll have regular antenatal check-ups and it's important to attend all of these, not only for the wellbeing of your baby but to keep an eye on your own health.
One condition which your midwife or GP will check for at every visit is pre-eclampsia, which is symptomless in its early stages and only detectable through routine blood pressure and urine tests. Pre-eclampsia affects one in every 10 pregnancies in the UK and it is a major cause of babies being born prematurely and of low birth weight. While it is usually mild and can be treated if picked up early, in rare cases the condition can be life threatening to both you and your baby.
The condition is called pre-eclampsia because it is the forerunner of a much more serious, although rare, condition called eclampsia. Pre-eclampsia is normally diagnosed by high blood pressure, traces of protein in your urine and sometimes swelling of the hands, feet and face. Slow growth of the baby may also be an indicator of the disease. Other symptoms can include a bad headache, blurred vision or severe pain below the ribs. If untreated and full-blown eclampsia develops this can lead to fits, unconsciousness and, in rare cases, can be fatal.
Pre-eclampsia is thought to affect up to one in five first pregnancies (one in 25 are severely affected) and one in ten of all pregnancies. The exact causes of the condition are still unknown, but it's caused by a partial failure of the blood supply to the placenta. The reason why first-time mums, or women pregnant by a new partner, are most at risk is thought to be to do with an immune reaction to the man's sperm. This reaction normally corrects itself by the second pregnancy. If you've had it once, you have a one in 20 chance of developing it in a subsequent pregnancy.
Lucilla Poston, professor of foetal medicine at King's College, London, has led research into the use of vitamins C and E to prevent pre-eclampsia. "Our research suggests that the action of free radicals may play a role in causing the condition," she says.
The condition is most common during the last few weeks of pregnancy, though you can get it at any time from 20 weeks onwards. Some women are more at risk than others - they include the under 20s and over 35s, women with existing high blood pressure, diabetics and women pregnant with twins or more.
What are the signs?
At every antenatal visit, your blood pressure will be measured and compared with the level it was at the start of your pregnancy. While it's not uncommon for your blood pressure to rise slightly later on in pregnancy, a reading of 140/90 or more is considered high by any standards. A sample of your urine will be tested for any traces of protein, a symptom of the condition. If you have a tiny trace of protein, but no other symptoms, this will be monitored by your midwife but probably won't indicate a problem. However, consistently high blood pressure and traces of protein in your urine will be diagnosed as pre-eclampsia and action will be taken. Your midwife will also check your hands and feet for signs of swelling, although this is also common in a normal pregnancy. A sudden gain in weight may also be a symptom.
What will happen next?
If you have either raised blood pressure or a trace of protein in your urine, you can expect more frequent antenatal check-ups. If nothing else happens, then your pregnancy is likely to continue as normal. However, if you have both high blood pressure and protein in your urine it's likely that you'll be referred to hospital for observation, tests and possibly drugs to reduce your blood pressure if it's very high. This may involve going in each day as an outpatient, but if pre-eclampsia is more severe you'll need to stay in hospital until your condition is stabilised. If pre-eclampsia gets worse, and especially if there are any signs of eclampsia such as severe headaches, your baby will need to be delivered early, either by induction or caesarian, as there is a danger that s/he may be starved of oxygen and food.
Can it be prevented?
If you've had pre-eclampsia in a previous pregnancy, you may be offered a Doppler scan at around 18-20 weeks next time, which can predict if you're likely to suffer from it again. Treatment can then be given to try and stop pre-eclampsia from re-occurring. However, this isn't 100% reliable. There have been cases of false negative and positive results with the scan. In women who have suffered severe, early-onset pre-eclampsia, prescribing low-dose aspirin throughout pregnancy may help to prevent the condition.
Vitamins may be the answer
A trial funded by Tommy's Campaign and led by professor Lucilla Poston, has found that a simple course of vitamins C and E may be able to prevent pre-eclampsia from developing. The trial involved 283 women, some of whom had already had pre-eclampsia and others who had been referred as the result of a Doppler scan. The researchers found that the women who had taken the vitamins displayed a 76% reduction in the occurrence of the disease.