Risk assessment scoring for thromboembolism: what proportions of obstetric patients are at risk?

Background Thromboembolism is the most common direct cause of maternal death in the UK (CEMACH 2003-05) because of inadequate risk assessments undertaken in early pregnancy. The significance of these risk factors was under appreciated in assessing most patients. The RCOG Green top guideline 37 (April 2009) includes guidance on which patients should receive antenatal and/or postnatal thromboprophylaxis. However, no data are given as to the frequency of these risk factors in the population. Methods This is a retrospective review of all women who delivered (including elective Caesarean Sections) between 4 December 2009 and 11 December 2009. Results During the study period, 113 patients delivered. Data were available on 104 (for 9 patients, the notes were not available). Eight patients (7.7%) met the criteria for being offered antenatal thromboprophylaxis and a further 17 could be considered for thromboprophylaxis if admitted to hospital (16.3%) and 44 patients (42.3%) met the criteria for postnatal thromboprophylaxis for 7 days or more. In our unit this equates to 2400 postnatal patients per year. Discussion Adherence to the RCOG guideline may result in a significant number of patients being offered thromboprophylaxis. This may not be deliverable with current staffing levels and length of stay. This study is likely to underestimate numbers as a comprehensive risk assessment at the time of booking was not taken at the time of the study, so risk factors such as family history or varicose veins may be missed. This study will be useful to units planning their thromboprophylaxis policy.