Sildenafil citrate decreased natural killer cell activity and enhanced chance of successful pregnancy in women with a history of recurrent miscarriage.

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.