Pregnancy and thrombotic risk

Abstract

Pregnancy increases the risk of thrombosis three-fold to four-fold. The main reason for the increased risk is hypercoagulability, which has likely evolved to protect women against the bleeding challenges associated with miscarriage and childbirth. The hypercoagulability of pregnancy is present as early as the first trimester and so is the increased risk of thrombosis. Factors that further increase the risk of thromboembolism in pregnancy include a history of thrombosis, inherited and acquired thrombophilia, certain medical conditions, and complications of pregnancy and childbirth. Candidates for anticoagulation are women with a current thrombosis, a history of thrombosis, thrombophilia, and a history of poor pregnancy outcome, or risk factors for postpartum thrombosis. For fetal reasons, the preferred agents for anticoagulation in pregnancy are heparins. There are no large trials of anticoagulation in pregnancy and recommendations are based on case series and the opinion of experts. Nonetheless, anticoagulation is believed to improve the outcome of pregnancy for women at risk.

Effects of enoxaparin and unfractionated heparin in prophylactic and therapeutic doses on the fertility of female Wistar rats

“…However, there is still controversy regarding their use because there are no large clinical trials of anticoagulation in pregnancy and experimental studies are scarce 17,18 . In addition, we performed a literature search on both prophylactic and therapeutic drug dosages and its relationship with fertility rates in rats and found that these studies have been limited.…”

Venous thromboembolism in pregnancy and nursing care

“…Venöz tromboemboli riski özellikle doğum sonu dö-nemde gebelik dönemindekinden daha yüksektir (9)(10)(11) .…”

Eficácia de intervenção com enoxaparina baseada em sistema de pontuação nos desfechos perinatais de gestantes com trombofilias

“…Estudos disponíveis embasam-se em pequeno número de pacientes e com critérios para a seleção das pacientes muito divergentes [12][13][14] . Cabe ressaltar que o impacto da tromboprofilaxia com a heparina de baixo peso molecular (HBPM) e a história obstétrica prévia ainda necessitam ser esclarecidos, pois não existem grandes casuísticas sobre anticoagulação na gravidez, e as recomendações são baseadas em séries de casos e opiniões de especialistas 8,9,15,16 . Não existem critérios bem definidos para o diagnóstico ou tratamento das trombofilias e gravidez, e o manejo dessas pacientes é embasado essencialmente no julgamento clínico 8,9,17 .…”