Protein S and protein C levels in Chinese women during pregnancy, delivery and the puerperium

Abstract

The plasma levels of protein S and protein C related antigens were determined in a group of normal pregnant Chinese women and a group of normal non-pregnant controls, using the sandwich technique of enzyme immunoassay with commercial kits. Compared with non-pregnant controls, plasma protein S levels were significantly lower during pregnancy, labour, parturition and the early puerperium. There was no significant difference in protein S levels between pregnancy, labour and puerperium. On the other hand, maternal plasma protein C levels during pregnancy and before delivery were similar to those in controls, but a significant increase was found during the third stage of labour. This increase did not persist into the early puerperium. The observed increase in protein C level immediately after delivery in our study may represent a physiological response to counter the tendency towards venous thrombosis in the parturient women, and may help to explain the almost negligible occurrence of thromboembolism in Chinese obstetric patients.