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Resia Pretorius is a Professor in the department of Physiology, University of Pretoria. She is also Director of the Applied Morphology Research Centre at the University. She has published over 150 research articles in rated scientific journals. She has also been study leader to 28 MSc and PhD students. In December 2011, she was named as winner of the African Union Kwame Nkrumah Scientific Awards for the Southern Region in the category: Basic Science, Technology and Innovation.

Tuesday, May 3, 2011

Thrombosis and Pregnancy



An important issue raised by one of the bloggers is the fact that during pregnancy, there is a tendancy for thrombosis. Remember, stroke can result is either haemorage of a blood vessel or clotting of a vessel, typically formed by fibrin mass or "clot".

During preganancy, the haemostatic status changes, to, amongst others, accomodate and prepare the body for child birth. An important factor here is that the body does not want too much blood loss and therefore, in normal pregnancy there is an increase in procoagulant activity. Also, the fibrinolytic activity (breaking up of fibrin after it has formed) is impaired and remains low during labor and delivery, but returns rapidly to normal, following delivery.

In a 2009 article in Blood, Coagulation and Fibrinolysis, my research team showed ultrastructural changes in fibrin networks found in pregnant individuals and compared this to non-pregnant individuals. Typically thick, major fibers and irregularly placed thin, minor fibers are present in healthy, non-pregnant individuals. In this qualitative assessment, changes in fibrin networks and platelet morphology were studied with scanning electron microscopy in healthy individuals, a healthy individual at 30 weeks pregnancy and post partum. These morphological changes seen during pregnancy might contribute to increased thrombotic risk, because, due to the denser appearance of fibrin networks due to the fine minor network morphology during pregnancy, clots might take longer to be broken down by normal fibrinolytic activity.


E Pretorius, P Bronkhorst, S Briedenhann, E Smit, RC Franz. 2009. Comparisons of the fibrin networks during pregnancy, non-pregnancy and pregnancy during dysfibrinogenaemia using the scanning electron microscope. Blood, Coagulation and Fibrinolysis 20(1):12-16.

PUBMED LINK TO ARTICLE:
http://www.ncbi.nlm.nih.gov/pubmed?term=COMPARISONS%20OF%20THE%20FIBRIN%20NETWORKS%20DURING%20PREGNANCY%2C%20NON-PREGNANCY%20AND%20PREGNANCY%20DURING%20DYSFIBRINOGENAEMIA%20USING%20THE%20SCANNING%20ELECTRON%20MICROSCOPE