Miriam's casebook - A mother with pre-eclampsia
During Amie's first pregnancy three years ago she had very mild pre-eclampsia in the last trimester. Amie had a normal delivery and a healthy baby, but she's worried pre-eclampsia will come back during her second pregnancy, with more complications. Amie's mother had high blood pressure during pregnancy, a symptom of pre-eclampsia, so Amie knows she has a higher risk of developing the condition.
This condition, which is unique to pregnant women, has the following symptoms: a rise in blood pressure, swollen ankles, feet, and hands, and protein in the urine. Although nothing can be done to prevent pre-eclampsia, good antenatal care can make sure that the condition does not get worse.
Pre-eclampsia is most common in first pregnancies, so I would hope that in a way Amie's been exposed to the highest risk already. Second, her pre-eclampsia was very mild. Her symptoms were slight oedema - swelling of the hands, fingers, feet, and face - and a marginally raised blood pressure that needed no treatment. She didn't have the other important sign of pre-eclampsia, the appearance of protein in the urine. Best of all, the pre-eclampsia came on only four weeks before the birth. Statistics show that the later pre-eclampsia starts in pregnancy, the lower the risk of it happening in a second pregnancy. In the end, Amie had a normal vaginal delivery and her baby was healthy.
What are the causes of pre-eclampsia?
Pre-eclampsia is an illness that happens only in pregnancy, potentially affecting mother and baby, and is most common towards the end of pregnancy. We don't really know what causes pre-eclampsia, although it seems to run in families - the daughters of women who have had pre-eclampsia are slightly more likely to get it themselves. Pre-eclampsia isn't caused or prevented by what you eat; by how you feel about your pregnancy; by whether or not you exercise; by how hard you work; or by how much rest you take.
Amie ate healthily and had heard that a high-protein diet might protect her against pre-eclampsia, but I had to tell her that there's nothing to support this theory. Some people say that calcium and fish oil supplements may help, but the evidence isn't strong enough for me to recommend that she add any supplements to her diet.
How the placenta is affected
What's known for certain is that pre-eclampsia starts in the placenta. Towards the end of pregnancy the placenta gets as large as a dinner plate, about 5cm (2in) thick, and needs a large and efficient blood supply from the mother to keep her baby growing healthily. In pre-eclampsia the placenta seems to run short of an adequate blood supply, and this has potentially serious consequences for mother and baby.
Key symptoms of pre-eclampsia are a rise in blood pressure and swelling of the fingers, hands, feet, and face. An antenatal urine test may also show that protein has leaked into the urine from kidneys that can't function as effectively as before and the blood-clotting mechanism may also be affected. It's likely that if pre-eclampsia did come back in her second pregnancy it would be milder than before. Nonetheless I advised Amie to take a close interest in the results of her antenatal tests.
I told Amie to make sure she has excellent antenatal care throughout her pregnancy. Because she's had the condition before, she may be asked to come for more frequent antenatal visits than usual, especially if any signs of pre-eclampsia are detected.
Understanding tests and treatment
While there are no screening tests that can predict Amie's risk of developing pre-eclampsia, there are some baseline tests that she could have done in the first half of her pregnancy. These can be repeated at regular intervals to give early warning of the onset of pre-eclampsia. So apart from the normal checks on blood pressure, urine, and her weight, she may be offered tests for kidney and liver function; ultrasound scans to track her baby's growth; and Doppler scans to measure the efficiency of blood flow to the placenta.
I reassured Amie that at the first sign of pre-eclampsia, in even its mildest form, she would be taken into hospital so that both she and her baby could be monitored. If necessary, her baby could be delivered before complications set in. Pre-eclampsia is progressive and doesn't get better, so once admitted Amie shouldn't expect to be allowed home until after her baby's been born.
Doctors may prescribe drugs to bring down a mother's blood pressure if it's found to be too high. Although these drugs don't affect the underlying disease, they can reduce the risk of some of the complications that are linked with it.
It's also possible that Amie may be given small daily doses of aspirin during her pregnancy, which could prevent or delay the onset of pre-eclampsia. The dose of aspirin works directly on the clotting blood cells, known as platelets, which are involved in pre-eclampsia.
Ensuring a safe delivery during pre-eclampsia
If pre-eclampsia is getting worse, if the baby shows signs of distress, or if the mother's condition is deteriorating, there's only one treatment: urgent delivery of the baby - sometimes by Caesarean section if the situation demands. Last time Amie had a normal delivery and the chances are she'll have the same this time. I reassured Amie that even if she did have a Caesarean, this wouldn't affect any subsequent deliveries. Women who've had one Caesarean section can try for a normal delivery next time. I suggested to Amie that if she did need a Caesarean, she could have regional rather than general anaesthesia, so she and her partner, Ed, could still take an active part in the birth of their child.
Seeking expert advice
All obstetricians are able to care for women at risk from or with pre-eclampsia. Research shows that the most important factor in a happy outcome to a pre-eclampsia birth is the involvement of doctors and midwives who are familiar with the condition and who can take action at once if there are any warning signs.
I advised Amie to get in touch with Action on Pre-Eclampsia (APEC), 84-88 Pinner Road, Harrow, HA1 4HZ.
Miriam's top tips
Naturally, Amie wants to be as well prepared as possible should there be any signs of pre-eclampsia during this pregnancy. My advice is to:
- keep an extra-careful watch for symptoms such as swollen ankles, hands, fingers, or face. Regular urine tests will alert carers to any traces of protein
- be vigilant about keeping antenatal appointments to ensure close monitoring throughout pregnancy.
- Medical emergencies in pregnancy
- Cervical incompetence
- Ectopic pregnancy
- Intra-uterine growth restriction
- Molar pregnancy
- Placenta praevia
- Placental abruption
- Pre-eclampsia and eclampsia
- Premature rupture of membranes
- Rhesus incompatibility
- Vaginal bleeding in pregnancy
- All about ectopic pregnancy
- Pregnancy: when you should call your doctor
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