External validation of a simple risk score based on the ASPRE trial algorithm for preterm pre‐eclampsia considering maternal characteristics in nulliparous pregnant women: a multicentre retrospective cohort study

Abstract

Objective To validate the performance of a first‐trimester simple risk score based on the ASPRE trial algorithm for pre‐eclampsia. Design Multicentre retrospective cohort analysis. Setting Four Italian hospitals. Population Unselected nulliparous women at 11–13 weeks of gestation from January 2014 through to January 2018. Methods Model performance was evaluated based on discrimination and calibration. Main outcome measures Delivery before 37 weeks of gestation with a diagnosis of pre‐eclampsia. Results Based on 73 preterm pre‐eclampsia cases and 7546 controls (including 101 cases of late pre‐eclampsia), the area under the receiver operating characteristics curve was 0.659 (95% CI 0.579–0.726). The sensitivity was 32.9% (95% CI 22.1–43.7) at a false‐positive rate of 8.8%. The positive likelihood ratio was 3.74 (95% CI 2.67–5.23), the positive predictive value was 3.49% (95% CI 2.12–4.86%) and the negative predictive value was 99.3% (95% CI 99.1–99.5%). The sensitivity and positive likelihood ratio were approximately 40% lower than in the original study. The calibration analysis showed a good agreement between observed and expected risks (P = 0.037). Comparison with the Fetal Medicine Foundation (FMF) algorithm yielded a difference in the area under the curve of 0.084 (P = 0.007). Conclusions In our Italian population, the simple risk score had a lower performance than expected for the prediction of preterm pre‐eclampsia in nulliparous women. The FMF algorithm applied to the same data set resulted in a better prediction. Tweetable abstract Simple risk score predicts preterm pre‐eclampsia in Italy.

Pregnancy outcomes in nulliparous women with positive first-trimester preterm preeclampsia screening test: the Great Obstetrical Syndromes cohort study

“…19 A multicenter cohort study of preterm PE screening using the FMF algorithm among nulliparous women at 11 to 13 weeks of gestation conducted in Italy reported a similar performance with an area under the curve of 0.74 (95% CI, 0.66e0.80) and a detection rate of approximately 53% for preterm PE at a false-positive rate of 10%. 20 Other studies validating the FMF algorithm in Swiss, 21 Belgian, 22 and Brazilian 23,24 populations, including both nulliparous and multiparous women, have obtained detection rates of preterm PE varying from 38% to 81% for 10% false-positive rates.…”

Real-world implementation and adaptation to local settings of first trimester preeclampsia screening in Italy: a systematic review

“…Thirty-eight studies were excluded for the following reasons: review, systematic review, meta-analysis, correspondence, or articles not reporting original data (n = 12), original articles of non-Italian study population (n = 18), original articles about screening for both PE and pregnancyinduced hypertension (n = 1), original articles about other PE screening strategies that excluded the first trimester (n = 6), and original articles not reporting data on screening performance (n = 1). Finally, nine articles were included in this review [11][12][13][14][15][16][18][19][20] (Fig. 1).…”

“…Brunelli et al [20] assessed the optimal screening tool for PE in an Italian population considering maternal characteristics in nulliparous pregnant women. The study included 73 preterm PE cases and 7546 controls (including 101 term PE).…”

“…Another demographic difference that affects screening performance is the rate of in vitro fertilization (IVF) in women who developed PE: from 12.9% to 27.5% in Italian population [16,20] versus 2-5% of the English population [23,28,29]. A recent study from our group observed that pregnancies obtained from oocyte donation have a higher risk of early PE [19].…”

Low-dose aspirin to prevent preeclampsia and growth restriction in nulliparous women identified by uterine artery Doppler as at high risk of preeclampsia: A double blinded randomized placebo-controlled trial

“…Antiplatelet agents are known to prevent preeclampsia and its consequences when they are administered before 16 weeks of gestation [ 5 , 6 ]. The difficulty, however, is early identification of pregnancies at high risk of preeclampsia that could benefit from this preventive treatment [ 7 , 8 ]. Parous women with a history of preeclampsia are candidates, but what is challenging is identifying nulliparous women who should receive this preventive treatment as they have roughly twice the risk to develop preeclampsia when compared to parous women [ 9 , 10 ].…”