Sildenafil Citrate in Early Unexplained Recurrent Pregnancy Loss

Recurrent unexplained spontaneous miscarriage (RSM) is defined as three consecutive pregnancy loss prior to 20 weeks from the last menstrual period. 1% to 2% of women experience RSM. Treatment of URSM is a challenging issue. The currently available lines of treatment according to simplicity of use, reliability and degree of invasiveness include corticosteroids, sildenafil citrate, aspirin, heparin and immunoglobulins (besides good antenatal care), but up to now there are no prospective randomized studies, powerful enough, to determine a significant difference between these therapeutic protocols, with any of the above mentioned pharmacological agents. Sildenafil Citrate (Viagra®), a vasodilator, is also described as an anti-inflammatory agent. While improving uterine blood flow in the proliferative phase, NO may have detrimental effects at the level of the endometrium during the implantation window. The NO- mediated release of cytokines such as tumour necrosis factor- from activated natural killer cells has been implicated as a cause of implantation failure. Based on these observations, this study attempts was made to study uterine arteries and sub-endometrial blood flow during the luteal phase in normal fertile women and in patients with Unexplained recurrent miscarriage