Tinzaparin thromboprophylaxis prescribing practice after caesarean delivery 2009-2014

National guidelines have been developed to ensure correct dosing of tinzaparin for women delivered by caesarean delivery (CD) to reduce the risk of venous thromboembolism.

The aim of this study is to examine the impact of implementation of national guidelines on thromboprophylaxis prescribing practice for women undergoing CD in a university maternity hospital.

Details of tinzaparin usage were obtained from the Hospital pharmacy for the years 2009-2014. Information on CD and pulmonary embolism (PE) were obtained from the Hospital's annual clinical reports.

Following guideline recommendations on weight-based tinzaparin for all women undergoing CD, the usage of syringes prefilled with tinzaparin 4500 IU increased from 526 to 8502 (P < 0.001) and usage of syringes prefilled with tinzaparin 10,000 IU increased from 36 to 910 (P < 0.001). Usage of syringes prefilled with tinzaparin 3500 IU decreased from 8216 in 2009 to 39 in 2014 (P < 0.001). During 2008-2010, there were two cases of PE after CD, both of whom received an inadequate dose of prophylactic tinzaparin. During 2011-2014 there were no cases of PE diagnosed after a total of 9427 CDs.

The development of national guidelines on thromboprophylaxis after CD was followed by a significant change in weight-based prescribing of tinzaparin. Following implementation, there have been no cases of PE after CD.