Screening for thrombophilia and antithrombotic prophylaxis in pregnancy: Guidelines of the Italian Society for Haemostasis and Thrombosis (SISET)

Abstract

The term thrombophilia describes an increased tendency to develop thrombosis and many laboratory markers with different strengths of association with thrombosis have been identified. The main causes of maternal mortality and morbidity in developed countries is venous thromboembolism (VTE) and obstetric complications. During pregnancy and puerperium the risk for VTE increases due to hemostatic imbalance towards a prothrombotic state, and it is further increased in women carriers of thrombophilia; recent studies have also demonstrated an association between thrombophilia and obstetric complications. These complications are, therefore, considered potentially preventable with the prophylactic administration of anticoagulant drugs, although their efficacy is not proven by data from randomized controlled trials. After a systematic comprehensive literature review and using a rigorous methodology, the expert panel formulated recommendations regarding the usefulness of screening for thrombophilia in pregnancy to identify high-risk women and for the management of antithrombotic prophyalxis. When evidence is lacking, consensus-based recommendations are provided.

Recommendations for prophylaxis of pregnancy‐related venous thromboembolism in carriers of inherited thrombophilia. Comment on the 2012 ACCP guidelines

“…The denial of thrombophilia as risk factor for pregnancy-related VTE in women with previous provoked VTE is consistent with some guidelines [3] but not with others [4][5][6][7]. Indeed, the paucity of data hampers a firm recommendation of not administering antenatal prophylaxis to pregnant women with thrombophilia and a previous nonhormonal provoked VTE.…”

“…Indeed, the paucity of data hampers a firm recommendation of not administering antenatal prophylaxis to pregnant women with thrombophilia and a previous nonhormonal provoked VTE. At the least, the magnitude of the risk associated with different abnormalities should be considered, as for women without previous VTE (see next section).Recommendations for pregnant women with inherited thrombophilia and no previous VTE LMWH prophylaxis throughout the pregnancy [3-6] and puerperium [3][4][5][6][7] is warranted in asymptomatic women with AT deficiency, homozygous FVL or PT20210A, or multiple thrombophilia abnormalities. Most guidelines put emphasis on the presence of additional risk factors for VTE (eg, family history of VTE, immobilization, obesity, age > 35 years, varicose veins).…”

“…Women with heterozygous FVL or PT20210A should receive antenatal LMWH prophylaxis only in the presence of such risk factors [3][4][5][6][7]. Recommendations for women with protein C (PC) or protein S (PS) deficiency are contrasting, suggesting antenatal LMWH in all of them [5,6] or only those with additional risk factors [3,4,7]. The duration of LMWH prophylaxis after delivery in asymptomatic women with PC or PS deficiency and with heterozygous FVL or PT20210A varies from at least 7 days [4] to 6 weeks for those with [4,6] or without [3,5,7] additional risk factors.…”

Laboratory Investigation of Thrombophilia / LABORATORIJSKO ISPITIVANJE TROMBOFILIJA

“…Therefore, the overall general screening of pregnant women is not indicated since the absolute risk and overall predictive value are relatively low (43,44). Instead, laboratory investigation of thrombophilia is indicated only in selected pregnant women with previous VTE or a positive family history of VTE in first degree relatives (10,45,46) influence the decision regarding antenatal thromboprophylaxis (45). For asymptomatic preg nant women with a family history of VTE, testing is advised if VTE in a first-degree relative was unprovoked, or provoked by pregnancy, OC use or a minor risk factor (10).…”

“…The results of different studies are contradictory and potential benefits of thrombophilia testing in this female population are not well-established at this time. Some expert groups suggest laboratory investigation of thrombophilia in pregnant women with previous obstetric complications including recurrent pregnancy loss, unexplained intrauterine fetal death, preeclampsia, abruptio placentae, HELLP syndrome and fetal growth restriction (46). According to the other experts, women with pregnancy loss that is either recurrent or late (second and third trimester) should be evaluated for thrombophilia, while the criteria for screening women with gestational vascular complications other than pregnancy loss are widely debated and vary in different maternal units (9,34,56,57,60).…”