Implementation of Multiple Marker Screening for Preterm Preeclampsia in a Single Tertiary Obstetric Centre

Objectives: Early assessment of pregnant individuals for risk of preterm preeclampsia (PE) is possible at the 11-14 week ultrasound visit using a validated multiple marker algorithm, allowing timely use of preventative low-dose acetylsalicylic acid (LDA) in high-risk patients. With no established early screening program for preterm PE in Canada, our objectives were to assess the acceptability and operational impact of routine screening for preterm PE during the 11-14 week ultrasound visit, evaluate uptake and adherence to LDA when recommended, and assess screening performance.

Methods: A prospective implementation study of preterm PE screening among pregnant patients at the ultrasound unit of a tertiary obstetric centre in Toronto, Canada.

Results: A total of 1057 patients were screened, with an acceptance rate of 87.1%. First-trimester ultrasound appointment time increased by a median time of 7 minutes (Interquartile range 6-9). By 16 weeks gestation, 88.7% of high-risk patients had started LDA, with adherence of 88.7%‒94.6% from 16‒36 weeks. Satisfaction with counselling was ≥7/10 in more than 95% of patients. There were 7 cases of preterm PE (0.73%), 3 in the low-risk group (0.35%), and 4 in the high-risk group (4.1%). When accounting for LDA use, the treatment-adjusted detection rate was 78.6%.

Conclusions: We demonstrate successful implementation of a validated, effective screening and prevention program for preterm PE as a first step in the implementation of a broader program adaptable for cultural, access/equity considerations, and marker availability.