Objective: To evaluate the effect of sildenafil on peripheral natural killer (NK) cell activity in women with a history of recurrent miscarriage (RM).
Design: Observational study.
Setting: University teaching hospital.
Patient(s): Thirty-eight nonpregnant women with a history of RM and 37 healthy women with previous successful pregnancy outcomes.
Intervention(s): Patients self-administered sildenafil suppositories (25 mg intravaginally, four times a day) for 36 days.
Main outcome measure(s): Peripheral blood NK-cell activity before and after vaginal sildenafil therapy in the RM women was measured using flow cytometry. In addition, the influence of 10 microg and 400 ng sildenafil on NK-cell activity after in vitro culture were determined. Uterine artery blood flow and endometrial thickness were recorded using Doppler ultrasound with an intravaginal probe.
Result(s): The NK-cell activity was significantly decreased after vaginal sildenafil therapy. Endometrial thickness was significantly increased after such therapy.
Conclusion(s): Vaginal sildenafil might be an interesting therapeutic option before conception in women with histories of reproductive failure.