This clinical trial is focused on studying preeclampsia, a condition that can occur during pregnancy, characterized by high blood pressure and potential damage to other organs, often the liver and kidneys. The study is investigating the use of acetylsalicylic acid, commonly known as aspirin, as a preventive treatment. Aspirin is being tested in a daily dose of 150 milligrams, taken orally in the form of a hard capsule. The trial aims to determine if aspirin can help prevent preterm preeclampsia, which is when the condition develops before 37 weeks of pregnancy, in women who are pregnant for the first time after using assisted reproductive technology, such as in vitro fertilization.

The purpose of the study is to evaluate the effect of aspirin compared to a placebo in preventing preterm preeclampsia. Participants will begin taking the medication between 9 and 14 weeks of pregnancy and continue until the 26th week. Throughout the study, various outcomes will be monitored, including the occurrence of preeclampsia, preterm birth, cesarean delivery, and other pregnancy-related complications. The study will also track the health of the newborn, including birth weight and any complications that may arise after birth.

Participants will be asked to adhere to the treatment regimen, and their adherence will be monitored by counting the pills at each visit and using a diary or application. The study will also consider the cost-effectiveness of the treatment, looking at the costs associated with hospitalizations, consultations, and other medical expenses. The trial is expected to conclude by the end of 2026, with recruitment having started in early 2023.