|
KMID : 0378019600030090057
|
|
New Medical Journal
1960 Volume.3 No. 9 p.57 ~ p.76
|
|
|
Changes of Blood Coagulation Factors during Pregnancy
|
|
|
|
|
Abstract
|
|
|
In a survey of recent literature has been found that extensive study of serial determinations for coagulation factors during all periods of pregnancy has been insufficiently carried out, there being only a few reports concerning certain coagulation factors of pregnant women and newborns.
The present study was undertaken to re-evaluate the coagulation factors in normal pregnant women who were in various stages of pregnancy in the light of the many recent advances in the knowledge of blood coagulation and with the availability of improved practical methods for the assay of the various factors involved. The study included 268 cases with no attempt to distinguish as to parity and age.
The classic theory of blood coagulation which consisted of two phases, was described in 1904 by Morawitz. The first phase was the formation of thrombin from prothrombin which occurred in the presence of thromboplastin and calcium. At that time it was th-,,,,r1,+ flint f1i, tnhnn1astin came from the nla-telets or from tissue. The second phase Ni the change of fibrinogen into fibrin in t presence of thrombin. No essenital chang were made in this theory until recently wh renewed interest in coagulation followed Qv ck´s description of the "one-stage prothror bin time" in 1935. A number of new facto were then described and several additions we: included in the coagulation mechanism;
was, however, complicated and confusing b+ cause of many synonyms in many factors.
Although recent theories of blood coagulat on are still controversial, Stefanini and mar other authors have agreed on the followin explanation.
The blood coaguation is initiated by the desi ruction of platelets with the release of the: factors. Platelet factor III and Antihemophili Globulin (AHG)in plasma form thromboplasti in the presence of several plasma thromboplas tin co-factors and calcium. Thus the fir: step of coagulation is finished. This thromt oplastin forms Converting Complex 1 in assoc iation with calcium and Stable Factor(Procon vertin) and this Complex I converts
minimal amount of pro thrombin into thrombin Thrombin is needed for the activation c the Labile Factor(Proaccelerin) as well a for autocatalysis for further destruction c platelets. The activated Labile Factor i converted to Ac-Globulin and forms Converting Complex II in association with Corn plex I, and this Complex II converts exces of prothrombin into thrombin in the present of calcium and platelet Factor I. Theschanged into fibrin and coagulatior occurs. This constitutes step III.
In addition to the above-mentioned factors there are other factors which oppose coagulation, namelyprocesses constitute step II of blood coagulation. In the presence of this, excess fibrinogen is antithromboplastin, antithrombin, heparin co-factor and profibrinolysin. in some pathological cases step IV of blood coagulation, which normally does not take place in the circulating blood, occurs by activation of profibrinolysin with lysokinase.
Based on this theory the following observation were performed :
1. Global test of blood coagulation factors Prior to studies of individual factors, global
tests of coagulation factors were investigated r
Instead of the well-known ´Lee White Meth-
od", the Heparin Tolerance Test (method by Marbet and Winterstein) and the Recalcification Time (method by Howell) were used because of greater accuracy. Compared with non-pregnant women, pregnant women showed no significant differences in Recalcification Time, while the Heparin Tolerance Test showed a slightly accelerated picture in blood coagulation in the latter half of pregnancy.
2. Observation of platelets(indirect method by Fonio) In my observation this showed no significant changes, while some authors described it as increasing and others with no change or as slightly decreasing.
Thromboplastin Time (Prothrombin time) When tested by the Quick one-stage method, it does not represent the prothrombin activi-ty alone any longer, but it shows the genera feature of step II of blood coagulation. M. data of Thromboplastin Time during pregna ncy showed a definitely more rapid cogaulatioi in comparison with non-pregnant women any this was more pronounced in the latter hat of the pregnancy. These data in general conf-4ormed with the data of many other authors.
4, Specific plasma prothrombin assay(method by Koller) This showed increased prothrombin during pregnancy, more pronounces in the Iatter half of the pregnancy.
5. The activity of the Labile Factor(method by Marbet and Winterstein)
This showed elevation during pregnancy, more pronounced in the latter half.
6, The activity of the Stable Factor (method by Marbet and Winterstein) This showed much elevation in pregnancy, more procounced in the latter half.
7. Fibrinogen determination (method by Schulz)
This showed a marked increase during pregnancy, more striking in the latter half.
These data were compatible with those of many other authors. These observations suggested the conclusion that despite a lack of increased blood coagulation during pregnancy, as determined by the global test, nearly all factors examined in this study, except for platelets, showed increased or elevated activities during pregnancy, and these increases were more pronounced in the latter half of the pregnancy,
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|
|