Case-control study of clotting differences using ROTEM testing in pregnant patients with early vaginal bleeding

Background

Vaginal bleeding in early pregnancy is a common presentation in the Emergency Department (ED), often resulting in pregnancy loss. Hypercoagulability exceeding normal physiological changes may be associated with miscarriage, but conventional clotting tests do not reliably detect this effect. Rotational thromboelastometry (ROTEM), which performs a more comprehensive clotting evaluation, may demonstrate coagulopathic abnormalities contributing to vaginal bleeding and miscarriage in early pregnancy that are not present in normal gestation.

Objective

This study aimed to evaluate the relationship between coagulation results from ROTEM testing in patients undergoing active evaluation for possible miscarriage compared to samples taken from asymptomatic patients with healthy pregnancies.

Study Design

This was a prospective case control study from a single center. Patients with chief complaint of vaginal bleeding in early pregnancy (less than 20 weeks) were recruited from the ED for ROTEM testing. These results were compared to healthy pregnant women presenting for routine prenatal care at our hospital’s obstetrical clinic. Crude results were analyzed using t-test for ROTEM measures, and differences were then compared using multiple linear regression, controlling for patient age, race, ethnicity, number of prior pregnancies, and estimated gestational age (EGA) in weeks. ROTEM measurements of interest were the clot formation kinetics using EXTEM, INTEM, and NATEM tracings.

Results

Over the study, 46 patients were recruited from the ED and 51 from the obstetric clinic. Both groups had similar mean ages, and racial and ethnic distribution. ED patients had earlier EGA than OB clinic patients, 7.6 weeks vs. 10.7 weeks, but higher patient age and higher number of prior pregnancies. ROTEM results were not significantly different between groups on univariate analysis except for INTEM CFT and INTEM MCF. After controlling for the patient age and estimated gestational age, no ROTEM result differed between groups.

Conclusion

In pregnant patients presenting to the ED with vaginal bleeding before 20 weeks, ROTEM differences were not different in comparison to healthy pregnant patients at the same gestation stage. This suggests that ROTEM clotting profiles may not be useful in the evaluation of vaginal bleeding within this population.