Optimizing the Use of Aspirin for the Prevention of Preeclampsia

The primary objective of the study is to demonstrate that in pregnant women at high risk for preeclampsia from first-trimester multiparametric screening, the incidence of preterm PE after discontinuation of ASA at 24-28 weeks of gestation is non-inferior to that of the control group, who continue ASA until 36 weeks.

Inclusion criteria

• Age 18 years or older at time of enrollment.
• Singleton pregnancy.
• Ability to read and understand the informed consent form.
• Having undergone first-trimester preeclampsia screening between 11+0 and 13+6 weeks of gestation using a validated multiparametric algorithm (FMF algorithm at a risk cutoff of 1:100, or Gaussian algorithm at a cutoff of 1:170) and being classified as high risk for preterm preeclampsia.
• Currently taking aspirin 150 mg/day initiated after first-trimester high-risk classification, in accordance with standard clinical practice.
• Voluntary signing of the informed consent form and willingness to comply with the study requirements, including acceptance of the assigned aspirin treatment duration, additional blood tests, and additional ultrasound assessments.

Exclusion criteria

• Early pregnancy loss, intrauterine fetal death, or fetus with major structural malformations diagnosed at the time of enrollment.
• Fetus affected by a known genetic or chromosomal disease.
• Contraindication, allergy, or intolerance to aspirin (acetylsalicylic acid).
• Any medical condition that makes aspirin discontinuation unsafe or impossible (e.g., antiphospholipid syndrome, mechanical heart valve, or other conditions requiring indefinite antiplatelet or anticoagulant therapy).