RecruitingClinical trialPrediction of Platelet Function Using Viscoelastic Test (ROTEM® Sigma) in Obstetric Anesthesia.This prospective observational, non-interventional, single-center study aims to evaluate whether the viscoelastic parameter PLTEM, derived from ROTEM® sigma testing (EXTEM-A5 minus FIBTEM-A5), can accurately estimate platelet count in obstetric patients with thrombocytopenia and/or severe postpartum hemorrhage. The study will include pregnant women older than 18 years managed during labor and delivery at the Hospital General Universitario Gregorio Marañón, Madrid (Spain). The primary objective is to validate the clinical usefulness of PLTEM as a rapid point-of-care tool to support clinical decision-making regarding neuraxial anesthesia and transfusion management in obstetric emergencies.