My 17 year old daughter has heterozygous factor V Leiden,Cardiolipin IgG and Protenaise C. She will be making a long haul flight of 8 hours then 14 hours immediately.She then stays in Barcelona for three days ,then a two hour flight to Santiago.She is there for two weeks then does the same trip back home.We have had conflicting advise as to how many clexane injections to use and when.She had full length grade 2 pressure stockings.This is all prophylactic as there has been a history of blood clots and PE in the family. Please can you assist me. Thank you Jacqueline