Application of a preeclampsia screening algorithm in a low-risk nulliparous population

The published study by O’Gorman et al1O’Gorman N. Wright D. Syngelaki A. et al.Competing risks model in screening for preeclampsia by maternal factors and biomarkers at 11-13 weeks gestation.Am J Obstet Gynecol. 2016; 214 (103.e1-103)PubMed Google Scholar focused on the Fetal Medicine Foundation report on the application of an a priori competing risk model in screening for preeclampsia. With the use of an algorithm that incorporated maternal factors, uterine artery Doppler pulsatility index, mean arterial blood pressure, serum pregnancy-associated plasma protein-A, and placental growth factor multiple of the median values at 11–13 weeks gestation, the risk of preterm (<37 weeks) and postterm (>37 weeks) preeclampsia was predicted. The study in question included an unselected cohort of low-, moderate- and at-risk women. For a false-positive rate of 10%, the screening algorithm accurately predicted 75% of preterm preeclampsia (area under the curve [AUC], 0.91) and 47% of postterm preeclampsia (AUC, 0.80). Our research group applied the same algorithm to a group of exclusively nulliparous women who were deemed low-risk (had no major risk factors for preeclampsia as predefined by the National Institute for Health and Clinical Excellence)2National Institute for Health and Clinical ExcellenceGuideline CG107: Hypertension in pregnancy: the management of hypertensive disorders during pregnancy.National Institute for Health and Clinical Excellence. 2010; (Available at:) (Accessed September 5, 2016)https://www.nice.org.uk/guidance/cg107Google Scholar as part of a 3-armed multicenter randomized controlled trial in Ireland that sought to determine the feasibility of routine low-dose aspirin vs screening test–indicated aspirin.3Mone F. Mulcahy C. McParland P. et al.An open-labeled controlled trial of low dose aspirin with an early screening test for pre-eclampsia and growth restriction (TEST): trial protocol.Contemp Clin Trials. 2016; 49: 143-148Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar In total, 546 women were screened at the outset, and results for all groups were revealed retrospectively and compared with outcomes.3Mone F. Mulcahy C. McParland P. et al.An open-labeled controlled trial of low dose aspirin with an early screening test for pre-eclampsia and growth restriction (TEST): trial protocol.Contemp Clin Trials. 2016; 49: 143-148Abstract Full Text Full Text PDF PubMed Scopus (15) Google Scholar The screening algorithm was performed by 1 of 2 sonographers under the guidance of the Fetal Medicine Foundation who applied a risk cut-off of >1:8 for a false-positive rate of 5% in an attempt to capture the majority of women with preeclampsia at <42 weeks gestation because our study numbers were significantly less than that from O’Gorman et al1O’Gorman N. Wright D. Syngelaki A. et al.Competing risks model in screening for preeclampsia by maternal factors and biomarkers at 11-13 weeks gestation.Am J Obstet Gynecol. 2016; 214 (103.e1-103)PubMed Google Scholar (n=546 vs 35,948). Despite this, our results were similar, with rates of preeclampsia 4.0% (22/546); the algorithm performed optimally for the detection of preterm preeclampsia (AUC, 0.86; 95% confidence interval [CI], 0.72–1.00) and less optimally for postterm preeclampsia (AUC, 0.70; 95% CI, 0.56–0.85). In relation to individual predictors (excluding maternal factors because all subjects were low-risk from the outset), placental growth factor performed most optimally (AUC, 0.89; 95% CI, 0.81–0.96). Similar to the findings of O’Gorman et al,1O’Gorman N. Wright D. Syngelaki A. et al.Competing risks model in screening for preeclampsia by maternal factors and biomarkers at 11-13 weeks gestation.Am J Obstet Gynecol. 2016; 214 (103.e1-103)PubMed Google Scholar pregnancy-associated plasma protein-A performed least optimally (AUC, 0.53; 95% CI, 0.30-0.76) in the prediction of preeclampsia. The findings of our study concur with those of O’Gorman et al1O’Gorman N. Wright D. Syngelaki A. et al.Competing risks model in screening for preeclampsia by maternal factors and biomarkers at 11-13 weeks gestation.Am J Obstet Gynecol. 2016; 214 (103.e1-103)PubMed Google Scholar when the Fetal Medicine Foundation algorithm is applied to low-risk nulliparous women of predominantly white ethnicity (540/546; 98.9%). Moving forward, it would be useful to be aware of the feasibility of the use of this algorithm in a resource-limited setting and whether consideration should be given to a universal aspirin policy without screening.4Mone F. Mulcahy C. McParland McAuliffe F.M. Should we recommend universal aspirin for all pregnant women?.Am J Obstet Gynecol. 2017; 216: 141.e1-141.e5Abstract Full Text Full Text PDF PubMed Scopus (48) Google Scholar Competing risks model in screening for preeclampsia by maternal factors and biomarkers at 11-13 weeks gestationAmerican Journal of Obstetrics & GynecologyVol. 214Issue 1PreviewPreeclampsia affects approximately 3% of all pregnancies and is a major cause of maternal and perinatal morbidity and death. In the last decade, extensive research has been devoted to early screening for preeclampsia with the aim of reducing the prevalence of the disease through pharmacologic intervention in the high-risk group starting from the first trimester of pregnancy. Full-Text PDF