Rotational thromboelastometry: NATEM and multiplate ASPI performed on 22 weeks of gestation. ROTEM: clotting time (CT) for ROTEM is defined as the time in minutes it takes for the trace to reach an amplitude of 2 mm. Clot formation time (CFT) is defined as the time necessary for clot amplitude to increase from 2 to 20 mm. Angle (α) is determined by creating a tangent line from the point of clot initiation (CT) to the slope of the developing curve. Maximum clot firmness (MCF) is the peak amplitude (strength) of the clot. Lysis Index 30 (LI30) is the percent reduction in MCF that exists when amplitude is measured 30 min after CT is detected. Multiplate: results are expressed in AUC (area under the curve = area under the aggregation curve) units (U) and are recorded against time. The AUC reflects overall platelet activity, which is affected by the height of the aggregation curve. Agonists tested multiplate ASPI (arachidonic acid; final concentration, 0.5 mmol/L).