Clinical features

Don't bother asking how long she has been pregnant: the trimester does not help predict DVT. ^b

Why?

• Deep vein thromboses are equally likely to occur in all three trimesters. ^b

DVT can occur in any trimester

Trimester b	% (95% CI)
first (0 to 91 days)	22% (13% to 35%)
second (92 to 182 days)	47% (33% to 60%)
third (183 days to term)	32% (19% to 44%)