Prophylaxis and Therapy of Venous Thrombotic Events (VTE) in Pregnancy and the Postpartum Period

Abstract

Venous thromboembolisms and pulmonary embolisms are one of the main causes of morbidity and mortality in pregnancy. The increased risk of thrombotic events caused by the physiological changes during pregnancy alone does not justify any medical antithrombotic prophylaxis. However, if there are also other risk factors such as a history of thromboses, hormonal stimulation as part of fertility treatment, thrombophilia, increased age of the pregnant woman, severe obesity or predisposing concomitant illnesses, the risk of thrombosis should be re-evaluated - if possible by a coagulation specialist - and drug prophylaxis should be initiated, where applicable. Low-molecular-weight heparins (LMWH) are the standard medication for the prophylaxis and treatment of thrombotic events in pregnancy and the postpartum period. Medical thrombosis prophylaxis started during pregnancy is generally continued for about six weeks following delivery due to the risk of thrombosis which peaks during the postpartum period. The same applies to therapeutic anticoagulation after the occurrence of a thrombotic event in pregnancy; here, a minimum duration of the therapy of three months should also be adhered to. During breastfeeding, LMWH or the oral anticoagulant warfarin can be considered; neither active substance passes into breast milk.

Keywords: anticoagulation; low-molecular-weight heparins; oral anticoagulants; pregnancy; thromboembolisms.

Fig. 1

Summary of the individual risk of thrombosis during pregnancy. If the total risk exceeds an imaginary “critical threshold” (dashed line), there is a manifestation of the thrombotic event.

Fig. 2

Primary prophylaxis of thrombotic events during pregnancy with the presence of predispositional risk factors.

Fig. 3

Primary prophylaxis of thrombotic events during pregnancy with the presence of thrombophilia. * Depending on the nature and severity of the inhibitor deficiency. ** Deep venous thrombosis, particularly in first-degree relatives. *** Depending on the nature and severity of the risk factor; where applicable, repeated examination in pregnancy is necessary. **** In the case of medical thrombosis prophylaxis conducted during pregnancy, this is also generally continued over 6 weeks post partum.

Fig. 4

Secondary prophylaxis following a prior VTE in pregnancy. * In particular hormonally triggered events (on hormonal contraception, hormone (replacement) therapy [HRT] or in earlier pregnancy). ** Where applicable, repeated review of acquired/expositional risk factors during pregnancy necessary.

Fig. 5

Anticoagulation in the appearance of thrombotic or thromboembolic events during pregnancy.

Abb. 1

Zusammensetzung des individuellen Thromboserisikos in der Schwangerschaft. Übersteigt das Gesamtrisiko eine imaginäre „kritische Schwelle“ (gestrichelte Linie), so kommt es zur Manifestation des thrombotischen Ereignisses.

Abb. 2

Primärprophylaxe thrombotischer Ereignisse im Rahmen der Schwangerschaft bei Vorliegen dispositioneller Risikofaktoren.

Abb. 3

Primärprophylaxe thrombotischer Ereignisse im Rahmen der Schwangerschaft bei Vorliegen einer Thrombophilie. * Abhängig von Art und Schwere des Inhibitorenmangels. ** Tiefe Venenthrombose insbesondere bei Verwandten 1. Grades. *** Abhängig von Art und Ausprägung des Risikofaktors, ggf. wiederholte Überprüfung in der Schwangerschaft erforderlich. **** Bei im Rahmen der Schwangerschaft durchgeführter medikamentöser Thromboseprophylaxe wird diese in der Regel auch über 6 Wochen postpartal fortgeführt.

Abb. 4

Sekundärprophylaxe nach abgelaufenen VTE in der Schwangerschaft. * Insbesondere hormonell getriggerte Ereignisse (unter hormoneller Kontrazeption, Hormon[ersatz]therapie [HRT] oder in früherer Schwangerschaft). ** Ggf. wiederholte Überprüfung auf erworbene/expositionelle Risikofaktoren im Rahmen der Schwangerschaft erforderlich.

Abb. 5

Antikoagulation bei Auftreten thrombotischer bzw. thromboembolischer Ereignisse im Rahmen einer Schwangerschaft.