Preeclampsia | BORN Ontario

Overview

Preeclampsia is a common and dangerous complication of pregnancy. Preeclampsia causes high blood pressure and excess protein in urine and affects approximately 2% of pregnancies in Ontario¹.

It can lead to preterm birth and other life-threatening complications and is a leading cause of maternal death.^2,3

Why This Matters

Standard screening for preeclampsia risk relies on a checklist of clinical risk factors in early pregnancy. Individuals identified as at risk can take a daily low-dose aspirin, which has been show to prevent 80%-94% of early-onset, severe preeclampsia.^4,5,6 However, an Ontario study⁷ found that more 60% of pregnant individuals who would benefit from daily low-dose aspiring are not receiving it.⁶

Recently, the Fetal Medicine Foundation (FMF) has validated a protocol for identifying individuals at risk for early-onset preeclampsia that considers:

clinical factors

A blood marker called placental growth factor (PlGF)

four standardized blood pressure measurements

an ultrasound to measure resistance to blood flow in the uterine arteries.

This protocol is effective in detecting up to 90% of pregnancies that develop early-onset preeclampsia.^5,8,9 In 2022, an Ontario Health Technology assessment¹⁰ concluded the FMF protocol is more accurate than current screening practices and the recommended exploring its implementation across Ontario.

BORN's Role

BORN and PSO, in conjunction with partners at the Ministry of Health, are committed to reducing the risk of early-onset preeclampsia for pregnant Ontarians. While the FMF protocol is a promising tool for predicting early-onset preeclampsia, it includes new measurements and tests so it is unclear how effectively primary care providers can implement it ,especially when Ontario’s primary care system is already strained.

To determine how to best implement the FMF protocol across the province, PSO and BORN Ontario are supporting two pilot projects led by Dr. Naana Jumah at Thunder Bay Regional Health Sciences Centre and Dr. Nan Okun at Sunnybrook Hospital’s DAN Women and Babies Program. Funded by Ontario’s AHSC AFP Innovation Fund, these projects will implement a pragmatic version the FMF protocol to all pregnant individuals, offering daily low-dose aspirin to all those at risk of early-onset preeclampsia. This flexible approach requires, at a minimum, clinicians to capture maternal clinical factors and PlFG, while additional elements of the protocol (e.g. mean arterial pressure, uterine artery ultrasound) will be included when feasible. This approach emphasizes feasibility to ensure that all pregnant individuals are screened so that those at risk can be offered daily low-dose aspirin.

These pilot studies will provide valuable insights into barriers and enablers for the FMF protocol, to inform the design and implementation of an effective and equitable universal preeclampsia screening and prevention program across Ontario.

Learn More

If you are a pregnant individual receiving care at Thunder Bay or DAN Women’s and Babies program Toronto region and you think you may be eligible to participate in the preeclampsia pilot study, please speak to your healthcare provider. If you live outside these regions, your healthcare provider can review your personal and clinical history to help determine your risk of preeclampsia.

To learn more about preeclampsia, watch the videos created by BORN Ontario, or go to www.preeclampsia.org for additional information.

Video Resources

Screening for Preeclampsia

Answering Questions About Race in Preeclampsia Screening

What to Do If You Are High Risk for Preeclampsia

Implementing Universal Preeclampsia Screening in Practice

Impact and Benefits

For Patients

Earlier identification of risk during pregnancy
Access to preventive interventions when appropriate
Improved monitoring and follow-up care
Potential reduction in severe complications for parent and baby
More informed discussions with healthcare providers

For Providers

Evidence-informed screening approaches
More consistent risk assessment practices
Support for timely preventive care and referrals
Improved ability to identify patients who may benefit from enhanced monitoring

For Healthcare

More equitable access to screening across Ontario
Improved maternal and newborn health outcomes
Potential reduction in complications associated with preterm birth and severe preeclampsia
Better use of data to support quality improvement and population health planning

Did You Know...

In Ontario, rates of preeclampsia and preterm birth are disproportionately high among Black individuals.¹¹ To ensure a universal screening program in Ontario is culturally responsive to the needs of Black communities, BORN Ontario is partnering with Black-led perinatal organizations and researchers. The goal is to identify unique barriers to screening and low-dose aspirin use, as well as co-design tailored supports and strategies that meet the needs of Black communities.

References

1. BORN Ontario. A Decade and Beyond: Perinatal Health in Ontario Report 2012–2024. Ottawa, Ontario; 2025.

2. Poon LC, Shennan A, Hyett JA, Kapur A, Hadar E, Divakar H, et al. The International Federation of Gynecology and Obstetrics ( FIGO ) initiative on pre‐eclampsia: A pragmatic guide for first‐trimester screening and prevention. Int J Gynecol Obstet. 2019 May;145(S1):1–33.

3. Sprague AE, Roberts NF, Lavin Venegas C, Nath T, Shah PS, Barrett J, et al. Mortality Following Childbirth in Ontario: A 20-Year Analysis of Temporal Trends and Causes. J Obstet Gynaecol Can JOGC J Obstet Gynecol Can JOGC. 2024 Oct 12;46(12):102689.

4. Foisy MA, Kingdom JC, Bujold E. Optimal Timing and Aspirin Dose for the Prevention of Preeclampsia. J Obstet Gynaecol Can. 2022 Nov;44(11):1131–2.

5. Rolnik DL, Wright D, Poon LCY, Syngelaki A, O’Gorman N, De Paco Matallana C, et al. ASPRE trial: performance of screening for preterm pre‐eclampsia. Ultrasound Obstet Gynecol. 2017 Oct;50(4):492–5.

6. Jain V, Bujold E. Screening for preeclampsia risk and prophylaxis with acetylsalicylic acid. CMAJ Can Med Assoc J J Assoc Medicale Can. 2023 Nov 20;195(45):E1557–8.

7. Ray JG, Abdulaziz KE, Berger H, DOH-NET (Diabetes, Obesity, and Hypertension in Pregnancy Research Network). Aspirin Use for Preeclampsia Prevention Among Women With Prepregnancy Diabetes, Obesity, and Hypertension. JAMA. 2022 Jan 25;327(4):388.

8. O’Gorman N, Wright D, Poon LC, Rolnik DL, Syngelaki A, Wright A, et al. Accuracy of competing‐risks model in screening for pre‐eclampsia by maternal factors and biomarkers at 11–13 weeks’ gestation. Ultrasound Obstet Gynecol. 2017 June;49(6):751–5.

9. Tan MY, Wright D, Syngelaki A, Akolekar R, Cicero S, Janga D, et al. Comparison of diagnostic accuracy of early screening for pre‐eclampsia by NICE guidelines and a method combining maternal factors and biomarkers: results of SPREE. Ultrasound Obstet Gynecol. 2018 June;51(6):743–50.

10. Ontario Health. First-Trimester Screening Program for the Risk of Pre-eclampsia Using a Multiple-Marker Algorithm [Internet]. 2022 Dec [cited 2025 Dec 17]. Available from: https://www.hqontario.ca/Portals/0/Documents/evidence/reports/recommendation-first-trimester-screening-program-for-the-risk-of-pre-eclampsia-using-a-multiple-marker-algorithm-en.pdf

11. Miao Q, Guo Y, Erwin E, Sharif F, Berhe M, Wen SW, et al. Racial variations of adverse perinatal outcomes: A population-based retrospective cohort study in Ontario, Canada. Harville EW, editor. PLOS ONE. 2022 June 30;17(6):e0269158.