:Preeclampsia affects between 2% and 5% of pregnancies and is one of the leading causes
of perinatal morbidity and mortality worldwide. Despite strong evidence that the combination
of systematic preeclampsia (PE) screening based on the Fetal Medicine Foundation (FMF,
London UK) preeclampsia risk calculation algorithm with treatment of high-risk patients
with low dose aspirin (ASA) reduces the incidence of preterm PE more than currently
used risk-factor based screening, real world implementation studies have not yet been
done in Canada.
: To assess the operational feasibility of implementing first trimester screening
and prevention of preterm preeclampsia (PE) (< 37 weeks) alongside a publicly funded
first trimester combined screening (FTS) program for aneuploidies.
: Prospective implementation study. Consecutive pregnant patients referred for FTS
(11-13+6 weeks) were offered screening for PE based on the FMF algorithm concomitantly
with their aneuploidy screen. Consenting participants were screened using maternal
risk factors (MF), mean arterial pressure (MAP), uterine artery Doppler pulsatility
index (UTAD PI), pregnancy-associated plasma protein-A (PAPP-A) and placental growth
factor (PLGF). Risk for preterm PE (< 37 weeks) was calculated using the FMF algorithm
and individuals with a risk score 1/100 were recommended to use aspirin (ASA) (162 mg OD @hs, <16-36 weeks). Implementation
metrics assessed included: acceptability; operational impact; proportion of aspirin
(ASA) initiation; quality and safety measures; and screen performance.
: Between Dec 1, 2020-April 23, 2021, 1124 patients consented to PE screening (98.3%
uptake) and 92 (8.2%) screened positive. Appointments for patients receiving FTS aneuploidy
and PE screening averaged 6 minutes longer than FTS alone, adding UTAD PI averaged
2 minutes. Of 92 patients who screened high-risk for PE, 72 (78.3%) were successfully
contacted prior to 16 week's gestation. Of these, 62 (86.1%) initiated aspirin, 10
(13.9%) did not. Performance audit identified a consistent negative bias with MAP
measurements (median MOM 10% below 1): other variables were satisfactory. There were
seven cases of preterm preeclampsia (0.69%); 5 and 2 in the high and low risk groups
respectively. Screening detected 5/7 (71.4 %) of preterm preeclampsia cases, with
improved performance after adjustment for ASA treatment effect.
: This study confirms the operational feasibility of implementing an evidence-based
PE screening and prevention program in a publicly funded Canadian setting. This will
facilitate implementation into clinical service and the scaling up of this program
at a regional and provincial level.