Plasma D-dinier reference ranges in pregnant Nigerians

Abstract

The use of D-dimer as a screening test for thromboembolic disorders has not been validated in pregnancy thus necessitating further studies. This cross sectional study was carried out among Pregnant Nigerians at the Nigerian Air Force Hospital Antenatal Clinic, Ikeja, Lagos. Objective: This study was to determine local reference ranges for plasma D-dimer in both pregnant and non-pregnant females and compare differences in both populations. Methods: Structured questionnaire s were administered on a total of 365 participants which included 71 apparently healthy non-pregnant females, 64 women in the first trimester of pregnancy (=27 weeks). Citrated blood was collected for estimation of prothrombin time (PT), activated partial thromboplastin time (aPTT), and D-dimer estimation by ELISA method. Aspartate aminotransferase (AST) and alanine aminotransferase enzymes (ALT) were estimated using the Hitachi chemistry analyzer. Reference ranges were estimated non-parametrically using the Reference Value Advisor V 2.1. Results: Median D-dimer level for non-pregnant females was 190ng/mL, while the median D-dimer levels for pregnant female in 1st, 2nd, and 3rd trimester were 485ng/ml; 620ng/mL; and 1185ng/mL respectively. Reference ranges were calculated to be 86-494ng/mL; 338-624ng/mL; 451-799ng/mL and 665-1262ng/mL for non-pregnant females, 1st, 2nd, and 3rd trimester of pregnancy respectively. Conclusion: A diagnostic algorithm for venous thromboembolism (VTE) in pregnant women which combines clinical suspicion with elevated plasma Ddimers levels above estimated reference range for each trimester should precede definitive formal imaging