Certain Types of Hormone Therapy Raise VTE Risk

Postmenopausal women taking oral hormone therapy (HT) have an increased risk for venous thromboembolism (VTE), according to new findings.

Researchers made this determination based on the results of a systematic review and meta-analysis of 9 case-control studies, 9 cohort studies, and 4 randomized controlled trials. Data were obtained from Medline, Cochrane Central, Embase, and

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Ultimately, results of the analysis indicated that women who were treated with oral HT—including estrogens and estrogens plus progestins HT (odds ratio [OR] 1.72), oral estrogen therapy (ET)-only (OR 1.43), and combined oral estrogen-progestin HT (OR 2.35)—had an elevated VTE risk compared with controls (women who received placebo or non-users of HT).

However, compared with controls, women who used non-oral HT did not have an increased VTE risk. ORs for each type of non-oral HT were:

  • 0.97 for estrogens and estrogens plus progestins
  • 0.95 for non-oral ET
  • 0.92 for non-oral combined estrogen-progestin therapy

When compared with each other, women who received oral HT demonstrated an increased risk for VTE compared with those who received non-oral HT (OR 1.66)

“VTE risk was increased in postmenopausal women with no previous thromboembolic events using oral HT,” the researchers wrote. “Non-oral HT did not significantly affect this risk.

“The quality of the evidence produced in our meta-analyses is low to moderate, and further clinical trials are needed to sort out the impact of different types of progestin and different estrogen doses and administration routes on VTE risk,” they concluded.

—Christina Vogt


Rovinski D, Ramos RB, Fighera TM, Casanova GK, Spritzer PM. Risk of venous thromboembolism events in postmenopausal women using oral versus non-oral hormone therapy: A systematic review and meta-analysis. Throm Res. 2018;168:83-95.