Fibrinolysis after delivery: caesarean section versus vaginal delivery

Caesarean section is associated with higher risk of thromboembolism than normal vaginal delivery. In order to elucidate if altered fibrinolysis contributes to this increased risk, 15 women who delivered by Caesarean section were observed in the 37th to 40th week of pregnancy, 1 h, 3 and 10 days after delivery and compared to 15 women who delivered vaginally. Before delivery no differences in fibrinolytic variables were observed between the two groups. The immediate post-delivery period was associated with significant (all p<0.05) and similar increases in tissue-type plasminogen activator (t-PA) activity (149 vs 129%, all figures: Caesarean section vs vaginal delivery) and t-PA antigen (46 vs 75%) and significant (all p<0.05) decreases in plasminogen activator inhibitor (PAI) activity (66 vs 69%) and PAI-1 antigen (74 vs 82%) in both groups. Only euglobulin activity was less enhanced (60 vs 159% increase, p<0.05). Three days after delivery all variables, except PAI activity, decreased significantly (all p<0.05) compared to values 1 h after delivery (t-PA activity: 37 vs 41%; t-PA antigen: 43 vs 51%; PAI-1 antigen: 80 vs 58%) and similarly in both groups. From the 3rd to the 10th day euglobulin activity, t-PA activity and t-PA antigen slightly increased. The venous occlusion test, which was performed before delivery, 3 and 10 days after delivery revealed no significant differences in fibrinolytic responses to such stimulation between the two groups investigated. It was concluded that changes in t-PA and PAI-1 observed after Caesarean section are not significantly different from those observed after normal vaginal delivery and therefore presumably do not contribute to increased risk of thromboembolism after Caesarean section.