RESUMEN
<p><b>OBJECTIVE</b>To observe the effects of mild moxibustion on the uterine microcirculation in patients of primary dysmenorrhea (PD) and explore the potential mechanism of mild moxibustion in the treatment of PD.</p><p><b>METHODS</b>A total of 30 patients were randomized into a treatment group and a waiting list group, 15 cases in each one. Additionally, 15 healthy people were collected in the healthy group. In the treatment group, the mild moxibustion was used at Guanyuan (CV 4) and Sanyinjiao (SP 6). The treatment was given once a day since 5 to 7 days before menstruation until menses, 20 min each time. The treatment lasted for 3 menstrual cycles. No any intervention was provided in the waiting list group and the healthy group. The three-dimensional Doppler ultrasound test was adopted to observe the changes of the relevant indexes of uterine arterial blood, such as the systolic velocity (Vs), the diastolic velocity (Vd), the mean velocity (Vm), peak systolic velocity/end diastolic velocity (S/D), pulsatility index (PI) and the resistance index (RI) before treatment and at the end of 3-menstrual-cycle treatment.</p><p><b>RESULTS</b>Before treatment, as compared with the healthy group, Vs, Vd and Vm reduced in the treatment group and the waiting list group, S/D, PI and RI increased in the treatment group (all <0.05). The differences were not significant in S/D, PI and RI between the waiting list group and the healthy group (all >0.05). After treatment for 3 menstrual cycles, Vs, Vd and Vm increased in the treatment group (all <0.05), S/D, PI and RI reduced (all <0.05). The difference was not significant in every index before and after trial in the waiting list group and the healthy group (all >0.05). After treatment, Vs, Vd and Vm in the treatment group were higher than those in the waiting list group (all <0.05) and the difference was not significant as compared with those in the healthy group (all >0.05). S/D, PI and RI in the treatment group were lower than those in the waiting list group and the healthy group (all <0.05).</p><p><b>CONCLUSION</b>The mild moxibustion remarkably improves the uterine microcirculation in PD patients, which is achieved possibly by increasing blood velocity and reducing vascular resistance.</p>