Age-Specific Reference Intervals for PT, aPTT, Fibrinogen and Thrombin Time for Parturient Women

Abstract

Background Parturient women are healthy individuals who require special consideration. Parturient women are considered to be in a hyper-coagulable state. For example, the fibrinogen (FIB) levels are often higher than the upper limit of normal reference intervals (RIs) in parturient women than in non-parturient healthy individuals (2–4 g/L).

Objective The aim of this study is to establish the RIs of pro-thrombin time (PT), activated partial thromboplastin time (aPTT), FIB levels and thrombin time (TT) for parturient women.

Materials and Methods Blood levels of PT, aPTT, FIB and TT were assayed on an ACL TOP 700 automatic coagulation analyser using plasma samples from 10,472 parturient women. Outlier results were excluded by using Tukey's test. The RIs were calculated by the Clinical and Laboratory Standards Institute C28-A3 guideline.

Results The RIs of PT, aPTT, FIB and TT were 8.7 to 12.1 seconds (8.7–12.2 seconds for 16–20 years old, 8.7–12.1 second for 21–25 years old, 8.6–12.0 second for 26–30 years old, 8.7–12.0 second for 31–35 years old, 8.7–12.6 second for 36–40 years old and 8.8–12.2 second for 41 years old), 22.9 to 42.3 seconds, 1.98 to 5.82 g/L and 9.9 to 16.7 seconds, respectively. PT levels were found to be positively associated with aging.

Conclusion The above-established age-specific RIs, defined by using a large dataset, may assist clinicians in making accurate medical decisions. This was the first study in which the RIs of PT, aPTT, FIB and TT were established for parturient women in different age groups.

Keywords

reference intervals - parturient women - pro-thrombin time - thromboplastin time - activated partial thromboplastin time

Authors' Contributions

Gao-Ming Zhang and Guo-ming Zhang designed the research; Wei Zhang and Guo-Ming Zhnag analysed the data; and Gao-Ming Zhang and Guo-Ming Zhang wrote the manuscript.

^∗ Wei Zhang and Guo-Ming Zhang are co-first authors and contributed equally to this work.

• References

• 1 Hansen AT, Andreasen BH, Salvig JD, Hvas AM. Changes in fibrin D-dimer, fibrinogen, and protein S during pregnancy. Scand J Clin Lab Invest 2011; 71 (02) 173-176
• 2 Parunov LA, Soshitova NP, Ovanesov MV, Panteleev MA, Serebriyskiy II. Epidemiology of venous thromboembolism (VTE) associated with pregnancy. Birth Defects Res C Embryo Today 2015; 105 (03) 167-184
• 3 Sharma S, Uprichard J, Moretti A, Boyce H, Szydlo R, Stocks G. Use of thromboelastography to assess the combined role of pregnancy and obesity on coagulation: a prospective study. Int J Obstet Anesth 2013; 22 (02) 113-118
• 4 Zhang G-M, Bai S-M, Zhang G-M, Ma XB. Reference intervals of carbohydrate antigen 19-9 in the apparently healthy adult population. J Clin Lab Anal 2018; 32 (05) e22380
• 5 CLSI. Defining, Establishing, and Verifying Reference Intervals in the Clinical Laboratory; Approved Guideline. 3rd ed. Wayne, PA: Clinical and Laboratory Standards Institute; 2010
• 6 The Medcalc software. Available at: https://www.medcalc.org/manual/age-related-reference-interval.php/ . Accessed December 13, 2018
• 7 MedCalc Version 18.11.6. Available at: https://www.medcalc.org/download.php/.Accessed December 13, 2018
• 8 One-way analysis of variance–ANOVA. Available at: https://www.medcalc.org/manual/one-way_analysis_of_variance.php/. Accessed December 13, 2018
• 9 Tests for normal distribution. Available at: https://www.medcalc.org/manual/testsfornormaldistribution.php/. Accessed December 13, 2018
• 10 Fuentes-Arderiu X, Mas-Serra R, Alumà-Trullàs A, Martí-Marcet MI, Dot-Bach D. ; Catalan Association for Clinical Laboratory; Sciences. Guideline for the production of multicentre physiological reference values using the same measurement system. A proposal of the Catalan Association for Clinical Laboratory Sciences. Clin Chem Lab Med 2004; 42 (07) 778-782
• 11 Cui C, Yang S, Zhang J. , et al. Trimester-specific coagulation and anticoagulation reference intervals for healthy pregnancy. Thromb Res 2017; 156: 82-86
• 12 Szecsi PB, Jørgensen M, Klajnbard A, Andersen MR, Colov NP, Stender S. Haemostatic reference intervals in pregnancy. Thromb Haemost 2010; 103 (04) 718-727