Changes in activated protein C resistance during normal pregnancy

• Published in: American journal of obstetrics and gynecology Vol. 177; no. 1; pp. 162 - 169
• Main Authors: Walker, Mark C., Garner, Peter R., Keely, Erin J., Rock, Gail A., Reis, Marciano D.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Mosby, Inc 01-07-1997; Elsevier
• Subjects: Activated protein C resistance; Adult; Biological and medical sciences; Blood Coagulation Factors - analysis; Blood Coagulation Factors - metabolism; Cross-Sectional Studies; Factor V - analysis; Factor V - genetics; Factor V - metabolism; Factor VIII - analysis; Factor VIII - metabolism; Female; Gynecology. Andrology. Obstetrics; Humans; Management. Prenatal diagnosis; medical complications of pregnance; Medical sciences; Mutation; Partial Thromboplastin Time; Polymerase Chain Reaction; Pregnancy - blood; Pregnancy - physiology; Pregnancy Trimester, First - blood; Pregnancy Trimester, Second - blood; Pregnancy Trimester, Third - blood; Pregnancy. Fetus. Placenta; Protein C - analysis; Protein C - genetics; Protein C - metabolism; Protein C - physiology; Protein S - analysis; Protein S - metabolism; Thrombin - analysis; Thrombin - physiology; Thrombomodulin - analysis; Thrombomodulin - physiology; thrombophilia; Activated protein C resistance; thrombophilia; medical complications of pregnance; Pregnancy; Human; Polymerase chain reaction; Resistance; Multicenter study; Cross sectional study; Exploration; Biology; Change; Molecular biology; C reactive protein
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/S0002-9378(97)70456-3

OBJECTIVE: The objective of this study was to determine the changes in activated protein C resistance that occur during normal pregnancy. STUDY DESIGN: In this cross-sectional study activated protein C was measured in 128 women with normal pregnancies in the first, second, and third trimesters and in nonpregnant control subjects with 24 to 39 women in each group. In addition, factor V, factor VIII, free protein S, and functional protein C were measured and correlated with activated protein C levels. Polymerase chain reaction for factor V Leiden mutation was performed. RESULTS: There was a significant fall in the activity of activated protein C in the second and third trimesters of pregnancy (p < 0.05). This was related to increased factor VIII and decreased free protein S levels (p = 0.002, R2 = 0.20). The prevalence of the factor V Leiden mutation was 7.3%. CONCLUSION: Resistance to activated protein C is increased in the second and third trimesters of pregnancy. This is related to the alterations in other coagulation proteins, a phenomenon normally occurring during pregnancy. (Am J Obstet Gynecol 1997;177:162-9.)