What is Pre-eclampsia?
Pre-eclampsia is a potentially serious pregnancy complication that affects roughly 2.5% of pregnancies. The symptoms usually present in the third trimester of pregnancy, but may occur at any time after 20 weeks gestation. Pre-eclampsia is characterised by high blood pressure and protein in the urine; swelling of the face, feet and hands are also frequently present. It can lead to significant, even fatal, complications for both mother and baby.
Some of the potential complications associated with pre-eclampsia include:
- Severe hypertension
- Renal problems
- Severe headaches
- Changes in vision, including temporary loss of vision, blurred vision or light sensitivity
- Upper abdominal pain, usually under your ribs, on the right side
- Nausea or vomiting
- Decreased urinary output
- Decreased levels of platelets in the blood (thrombocytopenia)
- Impaired liver function
- Placental abruption
Patients with a high risk of pre-eclampsia should be monitored and managed closely.
Pre-eclampsia screening is a simple way to identify a patient’s risk of developing pre-eclampsia and should be undertaken at the beginning of pregnancy for patients exhibiting known risk factors.
It can be offered to pregnant women of any age or risk category. It can be ordered for all naturally conceived or in vitro fertilisation (IVF) singleton pregnancies, including those with egg donors.
Some of the key known risk factors for pre-eclampsia include:
- Personal or family history of pre-eclampsia
- Chronic hypertension
- First pregnancy or new paternity
- Pre-existing diabetes
- High BMI
What is involved in Pre-eclampsia Screening?
Screening provides an individualised quantified representation of the patient’s overall risk of developing pre-eclampsia during their pregnancy.
The patient’s treating doctor will need to provide a specific referral for pre-eclampsia screening when requesting the 12-13+ weeks scan.
The patient will attend WUMe for their ultrasound and pre-eclampsia screening between 12 and 13w6d gestation.
At the time of the patient’s pregnancy scan, the following information will be gathered:
- Maternal history via questionnaire
- Levels of placental growth factor (PlGF) via a blood test (this can be done from 11 weeks, at the same time as having their cfDNA/ NIPT if collected at WUMe).
- Doppler ultrasound assessment of the uterine arteries to check blood flow to the placenta.
- Measurement of arterial blood pressure in both arms.
The results will be combined to calculate the patient’s overall risk of developing pre-eclampsia and the result communicated to the patient and referring doctor.
This is a screening test and careful clinical interpretation of results is always recommended.
- The Fetal Medicine Foundation (FMF) recommends that all pregnant women should be screened for pre-term PE in the first-trimester, combining tests with maternal risk factors, MPAP, UTPI, and PlGF in a one-step procedure.
- ASPRE was the biggest prospective, randomised, placebo controlled trial that showed that the use of low-dose aspirin was associated with a significant 62% reduction in the incidence of pre-term PE (<37 weeks GA) and an 82% reduction in the incidence of EO-PE (<34 weeks GA).
- Recently, studies 1,2,3,4 showed that the administration of low-dose aspirin in pregnancies at high risk of PE reduces the length of stay in the neonatal intensive care unit (NICU) by about 70% mainly through the prevention of EO-PE.
- The benefits of pre-eclampsia screening are diminished for patients who are already taking Aspirin.
- WUMe offers pre-eclampsia screening for singleton pregnancies only. The test is not available for twins or higher order multiple pregnancies.
- Bujold E et al. Prevention of preeclampsia and intrauterine growth restriction with aspirin started in early pregnancy: a meta-analysis. Obstet Gynecol. 2010;116:402-414.
- Roberge S et al. Early administration of low-dose aspirin for the prevention of preterm and term preeclampsia: a systematic review and meta-analysis. Fetal Diagn Ther.2012;31(3):141-146. doi:10.1159/000336662. Epub 2012 Mar 21.
- Roberge S et al. The role of aspirin dose on the prevention of preeclampsia and fetal growth restriction: systematic review and meta-analysis. Am J Obstet Gynecol. 2017 Feb;216(2):110-120.e6.
- Wright D et al. Secondary analysis of ASPRE trial. Am J Obstet Gynecol. 2018;612.e6.
- 5. Rolnik D et al. Routine first trimester combined screening for preterm preeclampsia in Australia: A multicenter clinical implementation cohort study. Int J Gynecol. Obstet. 2021;00;1-9.