Preeclampsia (PE) affects 2-3% of all pregnancies and is a major cause of maternal and perinatal morbidity and mortality. The current approach to screening for PE is based on the identification of risk factors from maternal characteristics and medical history. This approach, however, fails to identify a high proportion of cases of PE and does not provide individualised, patient-specific results.
The study aimed to prospectively validate in a large European population a first-trimester algorithm for prediction of PE that combines maternal characteristics and medical history with biomarkers and to evaluate a possible beneficial effect of aspirin initiated at 11 to 14 weeks of gestation in the prevention of PE in a multicentre, double-blind, placebo-controlled randomised trial.
The study was performed in six European countries and 13 centres. Maternal characteristics and history measured the uterine artery pulsatility index (UtPI) on ultrasound, the mean arterial pressure (MAP), serum concentration of pregnancy-associated plasma protein A (PAPP-A) and placental growth factor (PLGF) were recorded. Bayes theorem was used to combine the a priori risk from maternal factors with the results of biomarker measurements and estimate individual probabilities. In the randomised trial, the analysis was performed in an intention-to-treat basis and the treatment effect on the primary outcome (the development of PE with delivery before 37 weeks of gestation).
Combined screening for PE is superior to current guidelines, and aspirin, at a daily dose of 150 mg and given to high-risk patients from 11 to 14 weeks until 36 weeks of gestation, reduces the incidence preterm PE and the length of stay in NICU.