Haemostatic changes related to fibrin formation and fibrinolysis during the first trimester in normal pregnancy and in recurrent miscarriage.

We have studied some biophysical properties of the fibrin network during the normal state of pregnancy and in patients with recurrent miscarriage (RM), in the first trimester of pregnancy. The fibrin polymerization process, followed by turbidity, showed that the rate of fibrin monomer assembly and the final turbidity was increased in the pregnant group (normal and with history of RM) compared to non-pregnant women (normal and RM), which is consistent with the increased fibrinogen concentration during pregnancy. No changes were observed in the Darcy constant (Ks) of RM clots, pregnant or not; however, in pregnant control subjects the Ks increased (p = 0.03). The fibrin lysis rate was increased in pregnant women compared to non-pregnant, being faster in women with RM. The rheological properties of the fibrin network in the non-pregnant group (control and RM patients) were similar; in the pregnant state, the fibrin network of the control group was 1.3 times stiffer compared to the control non-pregnant women, and almost unchanged in RM patients. In this study we have found changes in the clot structure that seem to be related to normal pregnancy and an increased rate of the fibrin lysis process in the RM patients, which may have clinical relevance.

Parámetros hemostáticos en placenta de pacientes con embarazo normal y con preeclampsia severa / Hemostatic system parameters of placental extracts in normal pregnancy and severe preeclampsia

Con el objeto de buscar el mejor entendimiento del mecanismo hemostático en la preeclampsia, se estudiaron extractos de placentas obtenidos de 26 mujeres embarazadas normales (EN) y 12 pacientes con preeclampsia severa (PES), en los cuales se determinaron trombomodulina (TM), factor tisular (FT), activador tisular del plasminógeno (t-PA), inhibidores del activador del plasminógeno 1 y 2 (PAI-1 y PAI-2) y el inhibidor del factor tisular (TFPI). Los resultados mostraron concentraciones similares de FT, TM y PAI-2 en ambos grupos, t-PA incrementado no significativamente y el TFPI y el PAI-1 presentaron un incremento significativo en las placentas de PES

Prevalence of the coagulation factor XIII polymorphism Val34Leu in women with recurrent miscarriage.

BACKGROUND: Recurrent miscarriage (RM) syndrome is not an uncommon obstetrical problem of multifactorial etiology. We investigated the role of the coagulation factor XIII (FXIII) Val34Leu polymorphism in RM. METHODS: We recruited 80 subjects (40 normal and 40 with history of RM; of each group 20 pregnant and 20 non-pregnant) and analyzed the prevalence of this polymorphism. The women recruited for the present study had similar age and did not have history of any hemostatic disorders. FXIII levels and activity and the rate of fibrin cross-linking by FXIII genotype Val34Val and Val34Leu were studied. RESULTS: Genotype analyses of patients and normal revealed that the frequencies distribution of Val/Val and Val/leu were statistically similar (P<0.05): 62.5% and 60%, and 37.5% and 40%, respectively; no Leu/leu genotype was found. The FXIII-A subunit levels and activity were also found similar between Val/Val and Val/leu genotypes in the different groups, pregnant and non-pregnant, normal or with RM. The rate of FXIII alpha and gamma-chains fibrin cross-linking was not different between the 2 genotypes. CONCLUSION: From our results we conclude that FXIII Val34Leu polymorphism does not appear to be associated to RM.

[Hemostatic system parameters of placental extracts in normal pregnancy and severe preeclampsia]. / Parámetros hemostáticos en placenta de pacientes con embarazo normal y con preeclampsia severa.

To better understand the role of the hemostatic mechanism in preeclampsia, placental extracts obtained from 26 normal pregnant women (NP) and 12 patients with severe pre-eclampsia (SPE) were analyzed to determine thrombomodulin (TM), tissue factor (TF), tissue-type plasminogen activator (tPA), plasminogen activator inhibitor (PAI) 1 and 2, and TF pathway inhibitor (TFPI). The results showed similar concentrations of TF, TM and PAI-2 in both groups, while tPA increased no significantly and TFPI and PAI-1 increased significantly in SPE placentas.