Reduction in maternal complement levels during delivery by cesarean section

Aim: Primary elective cesarean sections are being carried out in considerable numbers in both developed and developing countries; however, little information is available concerning differences in maternal physiological responses associated with the mode of delivery. The aim of the present study was to compare the changes in the maternal complement and contact systems between delivery by cesarean section and vaginal delivery at term. Methods: Maternal levels of complement 3 (C3), complement 4 (C4) and coagulation factor XII (FXII) were measured during primary elective cesarean (n = 70) and vaginal (n = 140) deliveries. Results: The C3, C4 and FXII levels decreased significantly during delivery by cesarean section and remained low for two hours. By contrast, C3 levels, but not C4 levels, increased temporally during normal term delivery and FXII levels decreased two hours later. Conclusions: The changes in maternal C3, C4 and FXII levels during cesarean section were very different from those during delivery at term, suggesting that the maternal complement and contact systems respond differently.