Important Information about Pre-eclampsia and its Dangers

• Pre-eclampsia (PE) leads to high blood pressure and the presence of proteins in urine. In serious cases, liver and kidney function can also be significantly impacted, with the distinct possibility of this leading to blood platelet levels falling to the extent that seizures occur. The condition is a major cause of death in infants and mothers, as well as premature births.
• Current screening techniques for pre-eclampsia enable risk identification in up to 90% of cases, significantly higher than previous methods that were only able to identify risks in only 30% of cases.

An extremely pregnant woman lies at home on a couch,one hand on her head, the other on her stomach, exhausted and possibly feeling ill.

High blood pressure is one of the most common abnormalities to affect a pregnancy, with 10% of pregnant women experiencing this disorder. PE, on the other hand, affects around 2-5% of pregnancies. However, 10-15% of maternal deaths during a pregnancy are attributed to pre-eclampsia!

The symptoms of Pre-eclampsia

The symptoms of PE include high blood pressure and the presence of protein in urine, although swelling may also occur. If the condition is severe, liver and kidney function could be seriously impacted, while low blood platelet count and seizures are also distinct possibilities. All of this means that preeclampsia is one of the major causes of death for both babies and mothers during a pregnancy, as well as premature births.

While PE can be attributed to a number of factors, if the condition occurs before the 37^th week of a pregnancy, the cause is usually abnormal placental development or defective placentation. In cases of PE arising after the 37^th week of a pregnancy, these tend to result from abnormalities affecting the mother’s cardiovascular system, such as pre-existing, chronic high blood pressure and metabolic syndrome.

In the past, doctors would assess a pregnant female’s preeclampsia risk by looking at the following aspects:

• A prior pre-eclampsia pregnancy
• Chronic kidney disease
• Autoimmune disease (SLE)
• Diabetes
• Chronic high blood pressure

• First pregnancy at the age of 40 or above.
• The mother has a body mass index (BMI) score of 35kg/m2 or above during initial screening.
• The mother has a family history of pre-eclampsia.

Screening for the aforementioned risk factors allows medical staff to identify PE risk in only 30% of cases.

However, now there are screening techniques available which can identify the mother’s risk level, and provide protection against the occurrence of PE. Able to be carried out from the 11^th to 13^th week plus 6 days of a pregnancy, this screening technique enables identification in up to 90% of cases. The screening process involves a uterine artery Doppler ultrasound examination of both the right and left sides to be carried out in conjunction with a blood test in order to assess the levels of placental growth factor (PIGF), which are proteins that promotes vessel formation. This method is applied because women who are suffering from abnormal placental development will have lower-than-normal PIGF levels.

The screening requires inputting the uterine artery circulation scores of both sides, the PIGF level, and the maternal blood pressure ratings into software, which then calculates the mother’s personal preeclampsia risk. If the risk is found to be high, protection can be offered in the form of medication to be taken from the 16^th week until the 36^th week of the pregnancy, which will reduce the risk of PE occurring before the 37^th week by up to 70%.

References:

1. Ultrasound obstet gynecol 2018; 51: 743-750
2. Ultrasound obstet gynecol 2018 (ISUOG Practice Guidelines)