The levonorgestrel-releasing intrauterine system for endometrial protection during estrogen replacement therapy: a clinical review

Estrogen replacement therapy (ERT) is a well-established method of managing climacteric symptoms in women approaching the menopause, but it is associated with a significant risk of endometrial hyperplasia if unopposed by concomitant progestogen administration. The levonorgestrel-releasing intrauterine system (LNG-IUS) offers a highly effective method of minimizing this risk and has additional benefits beyond endometrial protection. The LNG-IUS provides excellent contraception, which may still be necessary in perimenopausal women, and is suitable for women with underlying conditions that may preclude their use of estrogen-containing contraceptive methods. It can effectively manage bleeding problems through the transition from perimenopause into menopause, with many women developing amenorrhea. The LNG-IUS is well tolerated with a favorable safety profile, which generally mirrors that of women of reproductive age using it for contraception only. Moreover, the LNG-IUS plus ERT combination does not appear to be associated with clinically relevant effects on plasma lipids or other markers of cardiovascular risk. Women using the LNG-IUS plus ERT also experience improvements in quality of life, and adherence and continuation rates are high. This review will summarize the clinical evidence for the use of the LNG-IUS plus ERT in peri- and postmenopausal women and present the key attributes of this combined therapy.