On Monday, 5-18-26, Stuart Lind, MD, University of Colorado Hospital and School of Medicine, asked, “Would you know of any primary references that validate cord blood levels?”
A PubMed search yielded this reference describing VWF levels, available from your medical library: Schneider DM, von Tempelhoff GF, Herrle B, Heilmann L. Maternal and cord blood hemostasis at delivery. J Perinat Med. 1997;25(1):55-61. doi: 10.1515/jpme.1997.25.1.55. PMID: 9085204.
Abstract
Today, we know that the coagulation system of the neonate differs in many ways from that of the adult system. We see a general reduction of the coagulation factors II-XIII (except VIII), the fibrinogen, and of the coagulation inhibitors ATIII, protein C, and heparin cofactor II at the same time. In addition, the newborns show different levels of the coagulation factors for premature and full-term infants. This situation necessitates the generation of not one, but several, reference ranges for the various components of the hemostatic system. While the above-mentioned factors of the coagulation and fibrinolytic system of the newborn are well studied, our knowledge of others is still lagging behind that of the adult. That applies to the vWF and PAI and even more to D-Dimer. Our aim was to collect some data for vWF, PAI, and D-Dimer to complete the understanding of the physiology of the hemostatic system in the newborn. Therefore, we used the blood samples from 59 newborns and their mothers to obtain a number of different components of the coagulation and fibrinolytic system. Besides some rheological parameters (erythrocyte aggregation, plasma viscosity) we measured the aPTT, PT, and the plasma levels of ATIII, fibrinogen, and protein C (PC). But we paid special attention to the plasma levels of von Willebrand factor (vWF), plasma activator inhibitor (PAI), and D-Dimer. The blood samples were collected from the umbilical cord and the cubital vein of the mother immediately after delivery, anti-coagulated, centrifuged, and stored until measurement at -70 degrees C. ATIII, aPTT, PT, and fibrinogen were measured by the clotting technique test on the Chromotimer (Behring, Marburg, Germany). D-Dimer, vWF, and protein C were determined with a commercially available ELISA obtained from Boehringer Mannheim (Mannheim, Germany). PAI activity was measured by a two-stage amiolytic method (Behring, Marburg). Besides the known differences of the neonatal hemostatic components to their mothers, such as a prolonged aPTT (52.19 s +/- 13.4 newborn, 35.26 s +/- 4.2 mother), reduced PT (64.34 s +/- 20.15 vs. 91.03 s +/- 1.25), ATIII (83.36% +/- 24.42 vs. 92.58% +/- 11.43) and fibrinogen (156.05 mg/dl +/- 91.68 vs. 344 mg/dl +/- 55.25), we found some peculiarities. The newborns show a clear reduction in the vWF (97.79 ng/ml +/- 36.33 vs. 183.43 ng/ml +/- 16.03) as well as the PAI (0.846 U/ml +/- 1.44 vs. 7.652 U/ml +/- 0.764). D-Dimer levels in the umbilical cord samples (1514.02 ng/ml +/- 953.56) are clearly prolonged in contrast to the maternal levels (740.2 ng/ml +/- 139.68). We were also able to find a difference of these factors related to gestational age. Premature infants showed a clearly higher level of PAI (2.2 U/ml +/- 2.86 vs. 0.69 +/- 1.13; p = 0.0136) compared with full-term infants, as well as significantly lower levels of ATIII (48.8% +/- 23.19 vs. 86.62 +/- 22.04; p = 0.0006) and protein C (25.33% +/- 9.37 vs. 35.73 +/- 7.53; p = 0.0027). D-Dimer, vWF, fibrinogen, and the rheological parameters are similar. This seems to show an increased tendency for bleeding with the premature infant. Newborns show a balance of the coagulation system solely on a lower level. This is due to the general reduction of the coagulation factors with a reduction of the coagulation inhibitors at the same time. The physiologically low level of the vitamin K-dependent and other coagulation factors and ATIII leads to a prolonged aPTT and reduced PT of the newborn. As well as these differences, known from literature, we found the following specialities: lower vWF and PAI, and higher D-Dimer levels of the newborn compared with their mothers.
Dr. Lind also located this open-access article: Bahakim H, Abdel Gader AGM, Al-Abdul Jabbar F, Gaaafar TH, Edrees YB. Coagulation parameters in maternal and cord blood at delivery. Annals of Saudi Medicine 1990 https://doi.org/10.5144/0256-4947.1990.149.
Abstract
A wide range of hemostatic variables were studied in 300 maternal/neonatal pairs at the time of delivery and also in 375 healthy nonpregnant women who served as controls. There was significant prolongation of the prothrombin time, partial thromboplastin time, and reptilase time in neonatal (cord) blood compared to maternal blood. The plasma levels of fibrinogen, antithrombin III, protein C, plasminogen, factor VIII coagulant and ristocetin cofactor activities, factor X, and platelet counts were significantly lower in neonatal than maternal plasma. In contrast, the thrombin time, alpha2-antiplasmin, and serum fibrin degradation products showed comparable values for both mothers and neonates. von Willebrand factor antigen showed a more significant elevation in mothers than in neonates; however, the ratio of von Willebrand factor antigen/factor VIII coagulant was similar in both (1.56 and 1.57, respectively). There was a significant correlation only between mothers’ factor VIII coagulant levels and their babies’ (r = 0.69; P < 0.05), but not for the other hemostatic variables studied. The differences between our results and those reported in smaller published studies are discussed.
He also located this article, available from your library: Fukui H, Takase T, Ikari H, et al. Factor VIII procoagulant activity, factor VIII-related antigen, and von Willebrand factor in newborn cord blood. Br J Haematol. 1979;42:637–46. doi: 10.1111/j.1365-2141.1979.tb01176.x. PMID: 314304.
Abstract
Summary. The mean level of factor VIII procoagulant activity (VIII:C) and factor VIII-related antigen (VIIIR:AG) was normal in 100 newborn cord plasmas, whereas that of von Willebrand factor (VIIIR:WF) activity was slightly lower than normal. On crossed immunoelectrophoresis, 20 of 50 newborn infants had an increased anodal mobility of VIIIR:AG. When the cord plasma showing an abnormal electrophoretic pattern was mixed with normal plasma, two precipitation peaks with a broad base were found. Similar mixing experiments with the abnormal cord plasma and plasma from a patient with atypical von Willebrand’s disease did not normalize the electrophoretic mobility of VIIIR:AG. Gel filtration of the cord plasma with an abnormal electrophoretic pattern of VIIIR:AG, showed that the three activities were all detected at the position corresponding to a molecular weight of about 800 000. The results suggest the presence of qualitative abnormalities of the factor VIII molecule in half of full-term newborn cord plasma.
Thanks to Dr. Lind for making this information available.
No comments here.