Short communication: Is there any benefit of initiating aspirin before the 11th week of gestation?

Aspirin initiated between 11 and 14 weeks of gestation reduces the risk of preterm preeclampsia and other placenta-mediated complications in screen-positive women. Most of these adverse outcomes are associated with maternal vascular malperfusion of the placenta, a disease that begins during the early first trimester. Assuming that aspirin has direct beneficial actions on the developing placenta, tempts clinicians to believe in the maxim that "the earlier the better", however neither the safety nor the effectiveness of aspirin started before 11th week of gestation has been demonstrated. Therefore, outside of research protocols, aspirin should not be started before the 11th week of pregnancy for the prevention of preeclampsia.