Abstract
Introduction Venous thromboembolism (VTE) is a significant cause of maternal mortality with the
greatest risk postpartum. Mode of delivery influences VTE risk, with emergency caesarean
section (CS) associated with the highest risk (CS). Thromboprophylaxis is recommended
for selected women to reduce the risk of VTE.
We aimed to investigate the impact of mode of delivery and thromboprophylaxis on hypercoagulability
as measured by thromboelastometry (TEM) and thrombin generation (TG) in women at high
VTE risk.
Materials and Methods Blood was collected from 99 pregnant women with VTE risk factors at up to five time
points from pre- (T1) and post (T2)-delivery to 6 weeks postpartum (T5). Multiple
linear regression was utilised to compare TG and TEM between those with vaginal delivery
(VD) and CS at each time point. Paired sample t-test with post hoc Bonferroni correction was utilised to compare laboratory markers
over time.
Results Women in both groups had a median of three postpartum VTE risk factors, with higher
body mass index and parity post-VD. In both the groups, TG and TEM parameters suggested
hypercoagulability at T2 compared with T1, with resolution at T5. There were minimal
differences between groups, apart from T2 with shorter clot formation time and higher
maximum clot firmness in the VD group.
Conclusion TG and TEM illustrate hypercoagulability associated with pregnancy and delivery.
The pattern of postpartum hypercoagulability seen in women with VTE risk factors was
similar irrespective of mode of delivery. Further research is required to establish
the effect of labour on TG/TEM in the absence of low molecular weight heparin use.
Keywords
enoxaparin - vaginal delivery - caesarean section - thrombin generation - thromboelastometry