Risk of venous thromboembolism during the use of oral estrogen-progestogen hormone therapies in light of most recent research findings

Two important studies evaluating the safety profile of oral estrogen-progestogen hormonal therapies conducted in standard clinical practice with respect to the venous system were recently published. A large prospective controlled cohort study (PRO-E2) based on the non-inferiority design has shown that the relative risk of developing venous thrombosis (VTE) in women using combined oral hormonal contraceptives (COHC) containing 17β-estradiol (1.5 mg) and nomegestrol acetate (2.5 mg) (E2/NOMAC) was not statistically different from that in users of COHC containing ethinylestradiol and levonorgestrel (EE/LNG). The aim of the recently presented study was to compare the risk of VTE in patients treated with a product for oral continuous combined menopausal hormone therapy containing 1 mg of 17ß-estradiol and 100 mg of micronized progesterone (1 mgE2/100 mgP4) with patients taking conjugated equine estrogens and medroxyprogesterone acetate (CEE/MPA). The study was based on an analysis of records retrieved from a US health insurance database, and was therefore concerned the real-life clinical practice. The hazard ratio of VTE when comparing 1 mgE2/100 mgP4 with CEE/MPA was 0.70 (95% CI: 0.53–0.92). The difference was found to be statistically significant (p < 0.05). The rewieved studies provide further evidence that the use of hormones bioidentical with endogenous steroids in oral contraception and menopausal hormone therapy creates an opportunity to combine high efficacy with a favorable safety profile.