What happens to PT and aPTT during pregnancy?

What happens to PT and aPTT during pregnancy?

• A. Increase significantly
• B. Decrease slightly
• C. No change
• D. Become unpredictable

Answer: (B)

During pregnancy the coagulation system shifts toward faster clot formation to help prevent severe bleeding at delivery. Levels of several clotting factors and fibrinogen rise, and natural anticoagulant activity can be reduced, making the blood more prone to clotting. Because of this procoagulant state, clotting times measured by PT and aPTT tend to shorten slightly or remain within the normal range rather than lengthening. So the best answer is that these times decrease slightly. They aren’t markedly shortened or unpredictable; the changes are modest and within the expected range for pregnancy.

During pregnancy the coagulation system shifts toward faster clot formation to help prevent severe bleeding at delivery. Levels of several clotting factors and fibrinogen rise, and natural anticoagulant activity can be reduced, making the blood more prone to clotting. Because of this procoagulant state, clotting times measured by PT and aPTT tend to shorten slightly or remain within the normal range rather than lengthening. So the best answer is that these times decrease slightly. They aren’t markedly shortened or unpredictable; the changes are modest and within the expected range for pregnancy.