Inclusion Criteria:  Patients who are willing to be followed up for 1 year and agreeing to give the informed consent will be included in the inclusion criteria.  Exclusion Criteria:  Any incomplete cases such as intrauterine death. Participants who fail to attend the scans after their first visit will be excluded. Patients with congenital vascular abnormalities/syndromes such as Klippel Klippel-Trenaunay syndrome. Patients who are unable to provide consent. Anyone who are taking part in any other research.  Potential participants who might not adequately understand verbal explanations or written information given in English, or who have special communication needs.  Patients with signs of acute deep vein thrombosis. Patient suffered from severe injury of their great-saphenous vein