Thrombosis and embolism in pregnancy and the puerperium, reducing the risk: what proportion of patients reach the threshold for thromboprophylaxis?

In November 2009 the Royal College of Obstetricians and Gynaecologists published an updated guideline, 'Reducing the risk of thrombosis and embolism during pregnancy and the puerperium'. This includes a clear and simple score-based risk assessment tool, designed for antenatal and postnatal patients. Thresholds are given at which thromboprophylaxis should be offered. However the proportion of patients who reach the threshold is not estimated in the guideline, and we are not aware of any published data regarding this. In this cross-sectional study, we studied the case-notes of all 109 deliveries conducted over a one-week period, including elective caesarean sections. Of those, 7% met the threshold for antenatal thromboprophylaxis and 41% met the threshold for postnatal thromboprophylaxis.