Maternal and pregnancy characteristics affect plasma fibrin monomer complexes and D-dimer reference ranges for venous thromboembolism in pregnancy

• Published in: American journal of obstetrics and gynecology Vol. 215; no. 4; pp. 466.e1 - 466.e8
• Main Authors: Grossman, Karin B., MD, Arya, Roopen, BMBCh, MA, PhD, FRCP, FRCPath, Peixoto, Alberto B., MD, Akolekar, Ranjit, MD, Staboulidou, Ismini, MD, Nicolaides, Kypros H., MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2016
• Subjects: Adult; African Continental Ancestry Group; Asian Continental Ancestry Group; Body Weight; Chronic Disease; Cocaine-Related Disorders - blood; D-dimer; European Continental Ancestry Group; Female; Fibrin Fibrinogen Degradation Products - metabolism; fibrin monomer complex; Gestational Age; Humans; Hypertension - blood; Obstetrics and Gynecology; Pregnancy; Pregnancy Complications, Cardiovascular - blood; Pregnancy Complications, Cardiovascular - diagnosis; Prospective Studies; Reference Values; screening; Sickle Cell Trait - blood; venous thromboembolism; Venous Thromboembolism - blood; Venous Thromboembolism - diagnosis; D-dimer; screening; venous thromboembolism; fibrin monomer complex; pregnancy
• ISSN: 0002-9378; 1097-6868
• DOI: 10.1016/j.ajog.2016.05.013

Background D-dimers have a high negative predictive value for excluding venous thromboembolism outside of pregnancy but the use in pregnancy remains controversial. A higher cut-off value has been proposed in pregnancy due to a continuous increase across gestation. Fibrin monomer complexes have been considered as an alternative diagnostic tool for exclusion of venous thromboembolism in pregnancy due to their different behavior. Objective We sought to establish normal values of fibrin monomer complexes and D-dimer as a diagnostic tool for the exclusion of venous thromboembolism in pregnancy and examine the effect of maternal and obstetric factors on these markers. Study Design Plasma D-dimer and fibrin monomer complexes were measured by quantitative immunoturbidimetry in 2870 women with singleton pregnancies attending their routine first-trimester hospital visit in a prospective screening study for adverse obstetric outcome. Multiple regression analysis was used to determine maternal characteristics and obstetric factors affecting the plasma concentrations and converting these into multiple of the median values after adjusting for significant maternal and obstetric characteristics. Results Plasma fibrin monomer complexes increased with maternal weight and were lower in women with a history of cocaine abuse and chronic hypertension. D-dimers increased with gestational age and maternal weight and were higher in sickle cell carriers and in women of African and South Asian racial origin compared to Caucasians. Conclusion Fibrin monomer complexes and D-dimers are affected by maternal and obstetric characteristics rather than only gestational age. The utility of these fibrin-linked markers as a tool for exclusion of venous thromboembolism in pregnancy might be improved by adjusting for patient-specific characteristics.