Guidelines Updated on Thromboembolic Disease in Pregnancy

Troy Brown, RN

April 14, 2015

The Royal College of Obstetricians and Gynaecologists (RCOG) released updated guidelines on preventing and treating thromboembolic disease in pregnancy, during childbirth, and after delivery. The guidelines were published April 13 and announced at the RCOG World Congress in Brisbane, Australia.

VTE occurs in approximately 1 in 1000 pregnancies. It can develop at any time during pregnancy, but the risk is highest during the first 6 weeks after birth, when it increases 20-fold. Risk factors for VTE include previous VTE or thrombophilia, obesity, increased maternal age, immobility and long-distance travel, hospital admission during pregnancy, cesarean delivery, and other comorbidities, including heart disease, inflammatory bowel disease, and preeclampsia.

Risk factors that occur during the first trimester of pregnancy include hyperemesis gravidarum, ovarian hyperstimulation, and in vitro fertilization pregnancy.

Reducing the Risk for Venous Thromboembolism

Catherine Nelson-Piercy, MA, FRCP, FRCOG, from Guy's and St Thomas' Hospital National Health Service Trust, London, United Kingdom, and colleagues produced the guideline on reducing the risk for venous thromboembolism during pregnancy on behalf of the RCOG. The guideline, Green-top Guideline 37a, updates the previous version published in 2009.

"The emphasis is on risk assessment with a recommendation that a formal VTE risk assessment with numerical scoring is employed for all pregnant and postpartum women," Andrew Thomson, MD, MRCOG, lead author of the guideline on treating thromboembolism and cochair of the RCOG Guidelines Committee, told Medscape Medical News.

"The guideline discusses risk factors that have only been identified in recent studies (eg, stillbirth and admission to hospital), changes in the threshold for employing thromboprophylaxis at different stages of pregnancy, clarification on the management of pregnant women who have an inherited or acquired thrombophilia, and when testing for thrombophilia is appropriate," Dr Thomson explained. "There are also changes to the timing of initiation of thromboprophylaxis acknowledging that many episodes of VTE occur early in pregnancy."

Depending on the number of current risk factors the woman has, thromboprophylaxis may begin at any time during pregnancy or postnatally and may continue as long as 6 weeks postnatally.

"The duration of postnatal thromboprophylaxis for women identified as being at risk has been extended from 7 to 10 days (and in some cases up to 6 weeks)," Dr Thomson said.

In addition, "the guideline clarifies that, at present, non-vitamin K antagonist oral anticoagulants are not recommended during pregnancy or postnatally in women who are breast-feeding."

Treatment of Venous Thromboembolism

Dr Thomson and Ian A Greer, FRCOG, from the University of Liverpool, United Kingdom, produced the revised guideline, Green-top Guideline No. 37b, on management of VTE on behalf of the RCOG.

The guideline recommends that individual hospitals have "an agreed protocol for the objective diagnosis of suspected VTE during pregnancy." The protocol may recommend the participation of obstetricians, radiologists, physicians, and hematologists.

"The most important updates in this guideline are an appraisal of D-dimer testing and pretest probability assessment, clarification on the use of ultrasound in the diagnosis of deep venous thrombosis, clarification of the fetal and maternal risks associated with diagnostic tests, the option of using once-daily low-molecular-weight heparin for the acute treatment of VTE in pregnancy, the benefits of extended low-molecular-weight heparin use in the prevention of postthrombotic syndrome, and [that] prolonged use (2 years) of graduated elastic compression stockings on the affected leg is no longer recommended for the prevention of post-thrombotic syndrome," Dr Thomson explained.

Future research should include the role of D-dimer testing and pretest probability scoring, clarification of the maternal and fetal radiation risks of diagnostic tests, evaluation of the role of newer diagnostic modalities, optimum dosage regimens for low-molecular-weight heparin, safety and efficacy of newer anticoagulants during pregnancy, and strategies for preventing and treating postthrombotic syndrome after DVT in pregnancy.

Nelson-Piercy reports commercial support for attending meetings/conferences from LEO Pharma and sanofi-aventis. One coauthor reports receiving commercial support for attending meetings/conferences from LEO Pharma and Pfizer and from Daiichi-Sankyo and Boehringer Ingelheim. He has received honoraria from Bayer, LEO Pharma, Boehringer Ingelheim, and Daiichi-Sankyo. Another coauthor has received fees for providing expert testimony. Another coauthor has received fees for reports as an expert witness and small honoraria for lectures. Dr Thomson was provided with a travel grant by LEO Pharma to attend an overseas conference in March 2014. Greer has disclosed no relevant financial relationships.

"Thrombosis and Embolism during Pregnancy and the Puerperium, Reducing the Risk." RCOG Green-top Guideline No. 37a. Published online April 13, 2015. Full text

"Thromboembolic Disease in Pregnancy and the Puerperium: Acute Management." RCOG Green-top Guideline No. 37b. Published online April 13, 2015. Full text


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