The effects of parity, oral contraceptive use and hormone replacement therapy on the incidence of varicose veins.J Obstet Gynaecol. 2006 Jul; 26(5):448-51.JO
Three population-based age cohorts (40-, 50- and 60-years old) of women (n = 3,590) were followed up to find out if pregnancies, use of oral contraceptives (OCs) or hormone replacement therapy (HRT) affect the appearance of varicose veins. Results were presented as odds ratios (OR) of prevalences at entry (POR) and as incidence odds ratios (IOR) during the 5-year follow-up. Parity with three or more births was an independent risk factor for varicose veins IOR 2.0 (95% confidence interval (CI), 1.0 - 3.9). OC use showed a small and not significant protective effect for varicose veins, both POR and IOR equal to 0.9. HRT use indicated an increased risk of varicose veins, with POR 1.3 (1.0 - 1.7), but in the follow-up, the effect disappeared, IOR 1.0 (0.5 - 1.9). As a conclusion, higher age and high parity are characteristic for varicose veins. The use of HRT or OCs do not increase the risk.