What is PIH?
Pre-eclampsia is a serious condition that can occur during pregnancy where there is high blood pressure and increased protein in the urine.
Although most cases of pre-eclampsia are mild and cause no trouble, the condition can get worse and be serious for both mother and baby. It can cause fits (seizures) in the mother, which is called 'eclampsia', and can affect the baby’s growth. It is life-threatening for mother and baby if left untreated.
Women can have pre-eclampsia and have no symptoms. It is therefore vital to have regular antenatal checks of blood pressure and urine to detect the condition before it becomes dangerous for mother and baby. If you have an antenatal appointment that you can’t attend, it is important to reschedule it.
Pre-eclampsia is sometimes called pregnancy-induced hypertension (PIH), pre-eclamptic toxemia or hypertensive disease of pregnancy.
Get medical help immediately if you are pregnant and you have severe abdominal pain, headache, dizziness, vision problems, confusion, nausea or vomiting, or if you experience a seizure, sudden swelling in your hands, ankles or face, trouble speaking, numbness or sudden and rapid weight gain.
Who is at risk?
About 3 to 4 in every 100 pregnant women in Australia and New Zealand develop pre-eclampsia. The exact causes are not known but you may be at higher risk of developing pre-eclampsia if you:
- have chronic hypertension (high blood pressure)
- have a chronic condition such as diabetes, an autoimmune disease or a kidney disorder
- have had pre-eclampsia before
- are aged 40 years or more or aged under 18 years
- are expecting twins or triplets
- have a family history of pre-eclampsia (i.e. your mother had pre-eclampsia)
- are very overweight at the beginning of your pregnancy (body mass index of 35 or more)
- have had a gap of 10 years or more since your last pregnancy
- conceived with in vitro fertilisation (IVF)
- have an autoimmune disorder such as rheumatoid arthritis
If you have any of these risk factors, it is very important to attend regular check-ups to have your blood pressure and urine tested.
What are the symptoms of PIH?
Pre-eclampsia can occur at any time during pregnancy, and up to 6 weeks after birth. It is most common after 20 weeks of pregnancy and in first pregnancies. It can develop gradually over many weeks, or come on suddenly over a few hours.
The first signs of pre-eclampsia are a sudden rise in blood pressure (hypertension) and protein in the urine.
You probably won't notice these symptoms, but your doctor or midwife should pick them up during your antenatal appointments.
As pre-eclampsia develops, it can cause fluid retention (oedema), which often causes sudden swelling of the feet, ankles, face and hands.
Oedema is another common symptom of pregnancy, but it tends to be in the lower parts of the body, such as the feet and ankles. It will gradually build up during the day. If the swelling is sudden, and it particularly affects the face and hands, it could be pre-eclampsia.
As pre-eclampsia progresses, it may cause:
- severe headaches that don’t go away with painkillers
- vision problems, such as blurring or seeing flashing lights
- severe pain in the upper abdomen (just below the ribs)
- heartburn that doesn’t go away with antacids
- excessive weight gain due to fluid retention
- feeling generally unwell
If you experience any of these symptoms, contact your doctor or midwife straight away.
However, it is possible to have severe pre-eclampsia without any symptoms.
Pre-eclampsia can also develop soon after childbirth, and you should alert your doctor or midwife of any concerns you may have after your baby is born.
Symptoms in the unborn baby
The main sign of pre-eclampsia in the unborn baby is slow growth. This is caused by poor blood supply through the placenta to the baby. The growing baby is starved of oxygen and nutrients and this will affect their growth.
How is PIH diagnosed?
If you are pregnant, your blood pressure will be checked at every antenatal appointment because a rise in blood pressure can be the first sign of pre-eclampsia. Pre-eclampsia can also be diagnosed by checking whether there is protein in the urine.
If your doctor or midwife is concerned about pre-eclampsia, they may order blood tests, an ultrasound or monitor the baby’s heart rate.
How is PIH treated?
Once pre-eclampsia develops, it does not go away until after the baby is born. Treatment may start with rest at home, but some women need to be admitted to hospital and to take medicines that lower high blood pressure and control the amount of fluid in the body. You may also have medication to prevent seizures.
Occasionally, the only way to treat pre-eclampsia is to deliver the baby early, either by induction of labour or a caesarean section.
After the birth, pre-eclampsia usually goes away quickly. However, there may still be complications so you may need to stay in hospital for several days and keep taking medication to keep your blood pressure down. If your baby is small or premature, they may need care in a special nursery.
How is PIH managed?
If you are concerned about pre-eclampsia, contact your doctor or midwife straight away.
If you are managing pre-eclampsia at home, make sure you drink enough to keep your urine a pale yellow colour. Do not use alcohol, drugs or cigarettes and make sure you go to all your antenatal appointments.
Gentle exercise and keeping your feet raised when you’re sitting down can help.
Complications of pre-eclampsia
If left untreated, pre-eclampsia can increase the risk of a stroke, impaired kidney and liver function, blood clotting problems, fluid on the lungs and seizures. There is also an increased risk that the placenta will separate from the wall of the uterus, causing bleeding (called placental abruption).
The baby may be born small, prematurely or may even be stillborn.
When should I see my doctor?
If you are still concerned about pre-eclampsia or pregnancy-induced hypertension, use healthdirect’s online Symptom Checker to get advice on when to seek medical attention. Ensure you attend regular antenatal visits as directed by your health professional and discuss then follow any professional advice given.
The Symptom Checker guides you to the next appropriate healthcare steps, whether it’s self-care, talking to a health professional, going to a hospital or calling triple zero (000).
Learn more here about the development and quality assurance of healthdirect content.
Last reviewed: September 2020