Abstract Number: PB2505
Meeting: ISTH 2020 Congress
Background: physiological changes that occur during pregnancy may affect biochemical parameters in women.
Aims: we assessed the analysis of population values for coagulation test prothrombin time (PT); INR, and Activated Partial Tromboplastin Time (APTT); according gestational trimester.
Methods: blood samples from 513 pregnant women ( 1-36 week) were collected in 0.32% trisodium citrate tubes (BD Medical Systems), centrifuged at 3.000 g for 10 minutes at room temperature .The women included, had uncomplicated pregnancies. Performed test were analyzed in an ACL Top 300 (IL) coagulometer, using: PT-Fibrinogen Hs Plus (IL), APTT-SP (liquid) (IL). The population was segmented in different trimesters of pregnancy. The data distribution was non parametric, the median and the 2.5 and 97.5 percentiles were used to describe the population. Regarding the values without pregnancy, the laboratory reference values were taken into account. One way Anova test was used to see if any quarter was significantly different.
Results:
| Test | Values without pregnancy | 1° trimester | 2° trimester | 3° trimester | p |
| n | 120 | 187 | 103 | 223 | |
| TP(%) | 70-120 | 88.5(73-110) | 100 (77-120) | 105 (81-131) | <0.001 |
| TP(Seg) | 13.8-18.3 | 14.6 (13.1-16.1) | 13.7(12.5-15.6) | 13.5 (12.1-15.2) | <0.001 |
| INR | 0.91-1.26 | 1.07 (0.95-1.2) | 1 (0.92-1.16) | 0.98 (0.88-1.12) | <0.001 |
| APTT(seg) | 24-35 | 30 (24.6-35) | 28 (25-35) | 28 (25-33) | <0.001 |
[Results of reference values and different trimesters]
Median and percentiles 2.5 and 97.5 are expressed in each trimester. When advancing in the weeks of pregnancy, there is a shortening of the APTT in seconds and an increase in the PT %, due to haemostatic change before delivery.
Conclusions: haemostatic reference intervals are generally based on samples from non-pregnant women. Gestational specific reference values are essential for the accurate interpretation of a subset of haemostatic test during pregnancy. The results depend on the double reagent/coagulometer; therefore it is recommended that each laboratory obtains its own reference values for pregnant women.
To cite this abstract in AMA style:
Iglesias Varela ML, Siracusa M, Paz M, Jacobsen D, Salguero N, Maggi L. Analysis of Population Values in Pregnant Women [abstract]. Res Pract Thromb Haemost. 2020; 4 (Suppl 1). https://abstracts.isth.org/abstract/analysis-of-population-values-in-pregnant-women/. Accessed January 26, 2022.« Back to ISTH 2020 Congress
ISTH Congress Abstracts - https://abstracts.isth.org/abstract/analysis-of-population-values-in-pregnant-women/