Pregnancy & Blood Pressure

What is pre-eclampsia?

Routine blood pressure and urine protein check-up during antenatal care is for the early detection of a condition known as pre-eclampsia, also known as pre-eclamptic toxaemia, or just toxaemia.

Pre-eclampsia is a serious pregnancy disorder characterised by high maternal blood pressure, protein in the urine and severe fluid retention. It is a fairly common complication of pregnancy and 1-2% of cases are severe enough to threaten the lives of both the mother and her unborn child.

There is no cure for the condition, except delivery of the baby.

What increases the risk of getting pre-eclampsia?

The factors that increase the risk of pre-eclampsia include:

  • First pregnancy
  • Different partner for every new pregnancy
  • Family history
  • Diabetes mellitus
  • Multiple pregnancies
  • Obesity
  • Extremes of maternal age
  • Pre-existing hypertension
  • Hydatidiform mole (relatively rare mass or tumour that can form within the uterus at the beginning of a pregnancy)
  • Hydrops fetalis (fluid accumulation in foetus)

The mother’s blood pressure usually returns to normal as soon as the baby is delivered.

What are the signs & symptoms of pre-eclampsia?

Pre-eclampsia can be asymptomatic, and may develop at any time after 20 weeks of pregnancy, but commonly develops during the later stages of pregnancy.

Pre-eclampsia most commonly causes high blood pressure and protein in the urine.

Some advanced symptoms include:

  • Hand and face swelling
  • Headache
  • Visual disturbance
  • Upper abdominal pain
  • Dizziness
  • Nausea and vomiting

How does pre-eclampsia affect your baby?

The placenta in the uterus is a special organ that allows oxygen and nutrients to pass from the mother’s bloodstream to the baby, and waste products (such as carbon dioxide) to pass from the baby’s bloodstream to the mother. In pre-eclampsia, blood flow to the placenta is obstructed. In severe cases, the baby can be gradually starved of oxygen and nutrients, which may affect its growth. All these lead to

  • Neonatal asphyxia (low oxygen)
  • Neonatal hypoglycaemia (low glucose)
  • Intrauterine growth restriction (low birth weight)

This growth restriction threatens the life of the baby and it may be necessary to deliver the baby prematurely. Another serious complication of pre-eclampsia is abruption, which means the placenta separates from the uterine wall and the woman experiences vaginal bleeding and abdominal pain. This is a medical emergency.

How is pre-eclampsia managed?

Since pre-eclampsia can be asymptomatic, regular antenatal check-up is advised. Bed rest, in early stages may control the situation, sometimes medication is needed to control blood pressure. But if the signs of toxaemia and poor foetal growth persist, it will often be necessary to induce labour and get the baby born a week or 2 early.

RANZCOGCalvary John James HospitalCanberra HospitalAustralian  National UniversityWomens HealthICS