Varicose veins (VV) are the early sign of Chronic venous insufficiency (CVI) which are characterised by abnormal tortuosity and dilatation of superficial veins of lower limb extremities. Factors for the development of VV exist in literature. However, the exact mechanism remains unclear. The prevalence of VV are greater in women compared to men and also higher in pregnant women compared to non-pregnant women which make pregnant women at higher risk of developing VV. Furthermore, complications of VV have negative impacts on patients' quality of life and health care budget. Therefore, better understanding of the cause of VV can contribute in better quality of life to the patient and provide valuable insights to help in reducing health care cost. The present study will investigate the contribution of both mechanical and chemical factors in pregnant women by taking blood samples for genomic testing, using Duplex ultrasound, vector flow imaging, limb volume assessment using Truncated cone tool, assessment of iliac vein compression using Photoplethysmography (PPG) technique, hormonal blood test and assessing patient's quality of life using Aberdeen Varicose Veins Questionnaire (AVVQ).

Initially, patients will be approached by a member of the direct care team in the Maternity outpatients' departments in the following hospitals: West Middlesex hospital, Queen Charlotte's and Chelsea hospital and St Mary's hospital. This will be managed by experienced research professionals in the area of vascular surgery. If a patient is prepared to discuss their potential role in this research, then the researchers will discuss the study and recruitment details at the patient's convenience. Recruitment is completely voluntary and will not affect their routine care, this will be made clear during the discussion regarding the research, and again during the consenting process. Time will be made available for any questions and for the patient to consider recruitment in their own time. Patients will be required to consent before any study-related procedures are carried out. Then her personal identifiable data will be coded and pseudonymised.

The recruited patient will be interviewed to obtain clinical information that is essential for robust analysis. This clinical information will include standard demographic form which will be used for all patients in each follow up in order to record and gather important information which represents the composition of the target population. Gathered data will include patients' details; patients name, day of visit, hospital name, ID number, date of birth. Furthermore, this demographic form will record potential risk factors which may associate with VV development such as race, number of pregnancies, family history of venous disease, BMI which include weight and height, occupational factors, smoking, alcohol consumption and diet. Any complications arising from pregnancy will be also recorded. Finally, this proposed study will only record fetal weight in second and third trimester to correlate increased fetal weight with potential venous pathology.

First, patients will be asked to fill the demographic form then will be asked to stand on a scale to measure the weight. Height will be recorded by bringing the horizontal measure down to rest on the top of the participants head. Following this, patient will be asked to sit while measurements are recorded in a relevant source data sheet.

Next, the patient will be asked to stand on a step facing the sonographer to assess the incidence of varicose veins using Duplex ultrasound (DUS) and vector flow imaging (VFI). While patient is standing, Truncated cone tool will be performed immediately by measuring leg circumferences in each segments of each limb to produce accurate measurements of lower limbs volume. Following this, patient will be asked to sit on a chair for perform Iliac vein compression test (venous outflow function) using photoplethysmography (PPG) technique. Finally, patient's quality of life assessment will be evaluated by using Aberdeen Varicose Veins Questionnaire (AVVQ) check list. Thereafter, the patient will be thanked for their participation and excused.

Clinical Laboratory tests will be managed and performed by experienced research professionals in the area of vascular surgery. Four appointments will be arranged for each patient to investigate DNA genomic testing and Estriol (E3) and progesterone hormonal testing. First appointment during first trimester will include both genomic DNA and hormonal blood tests. The three remaining appointments in the second trimester, third trimester and three months after giving birth will include hormonal blood samples only. Patients will be entitled to exit the study at any time without providing a reason, this is clearly stated on our information sheet and consent form. Verbal consent will be requested before all follow-up ultrasound scans.

Researchers will ensure that demographic data, ultrasound data, lower limb volume and iliac vein compression measurements, histopathological results and quality of life assessment results will be collected and stored in such a way that confidentiality is preserved. All data will be pseudonyms by replacing names with research codes and by keeping any identifying information separate from the main dataset.

The data will be analysed with the help of the Imperial College statistics department. The results of this study may be presented at local, national or international meetings or submitted for publication in a peer-reviewed journal. From a patient's perspective, all data will be pseudonyms before the statistical analysis phase of the study and plans to publish the results of the study are made clear in our patient information sheet.

Data and all appropriate documentation will be stored for a minimum of 10 years after the completion of the study, including the follow-up period.

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

Pregnant women

Pregnant women in their first trimester who are willing to be followed up for 1 year and agreeing to give the informed consent will be included in the inclusion criteria.