Implementation of routine first trimester combined screening for pre-eclampsia: a clinical effectiveness study

Objective Evaluate clinical effectiveness of the first trimester combined (FMF) pre-eclampsia screening programme when implemented in a public healthcare setting. Design Retrospective cohort study. Setting London tertiary hospital from January 2017 to March 2019. Methods 7720 women screened for pre-eclampsia according to National Institute for Health and Care Excellence (NICE) risk-based guidance and 4841 by the Fetal Medical Foundation (FMF) algorithm which combined maternal risk factors, blood pressure, PAPP-A and uterine artery Doppler indices in the first trimester. High risk was defined by standard NICE criteria in the pre-intervention cohort (prescribed 75 mg aspirin) or a risk of >= 1:50 for preterm pre-eclampsia from the FMF algorithm in the post-intervention cohort (prescribed 150 mg aspirin). Main outcome measures Screening effectiveness, rates of pre-eclampsia. Results The FMF screening programme resulted in a significant reduction in the screen-positive rate (16.1 versus 8.2%, odds ratio [OR] 0.50, 95% confidence interval [CI] 0.41-0.53) with a concurrent increase in targeted aspirin use in women classified as high risk for pre-eclampsia (28.9 versus 99.0%, OR 241.6, 95% CI 89.6-652.0). Screening indices were uniformly improved for the FMF algorithm with receiver operating characteristic (ROC) analysis demonstrating excellent discrimination for preterm pre-eclampsia (area under the curve [AUC] = 0.846, 95% CI 0.778-0.915,Pvalue <.001). Interrupted time series analysis showed that the FMF screening programme resulted in a significant 21-month relative effect reduction of 80% (P = .025) and 89% (P = .017), for preterm and early pre-eclampsia, respectively. Conclusions First trimester combined screening for pre-eclampsia is both feasible and effective in a public healthcare setting. Such an approach results in a two-fold de-escalation of risk, doubling of pre-eclampsia detection, near total physician compliance of aspirin use and a significant reduction in the prevalence of preterm pre-eclampsia. Tweetable abstract Implementation of 1st trimester combined pre-eclampsia screening effectively reduces prevalence of the disorder.