Sildenafil citrate decreased natural killer cell activity and enhanced chance of successful pregnancy in women with a history of recurrent miscarriage  Malgorzata Jerzak, M.D., Ph.D., Monika Kniotek, M.Sc., Jaroslaw Mrozek, M.D., Andrzej Górski, M.D., Ph.D., Wlodzimierz Baranowski, M.D., Ph.D.  Fertility and Sterility  Volume 90, Issue 5, Pages 1848-1853 (November 2008) DOI: 10.1016/j.fertnstert.2007.08.043 Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions

Figure 1 Uterine artery blood flow in woman with a history of eight recurrent miscarriages and increased number and activity of NK cells before (A) and after (B) vaginal sildenafil therapy. (A) Baseline sonographic evaluation of endometrial appearance and Doppler flow of the uterine artery. The endometrium is thin (4 mm) and the pulsatility index (PI) is high. (B) Sonographic endometrial appearance and Doppler flow of the uterine artery. The endometrium is thick (13 mm) and displays a trilaminar pattern. The PI was decreased compared with the baseline, indicating increased uterine blood flow. Fertility and Sterility 2008 90, 1848-1853DOI: (10.1016/j.fertnstert.2007.08.043) Copyright © 2008 American Society for Reproductive Medicine Terms and Conditions