The effect of diclofenac on uterine artery blood flow resistance during menstruation in patients with and without a copper intrauterine device

The aim was to evaluate the effect of diclofenac on uterine artery blood flow resistance during the first day of menstruation. A total of 28 regularly menstruating women were examined longitudinally with and without a copper intrauterine contraceptive device (IUD) by transvaginal colour Doppler ultrasonography. The uterine artery pulsatility index (PI) was first measured, after which 50 mg of diclofenac was infused i.v. After 15 min the PI was measured again. The patients evaluated their menstrual pain with a scoring system before and after the diclofenac infusion. The mean PI (SD) during menstruation was significantly lower with the IUD [2.13 (0.43)] than without [2.39 (0.62)], P = 0.05. The mean PI in nine patients who experienced advanced menstrual pain was also lower in the presence of the IUD [2.16 (0.42)] than without it [2.83 (0.78); P < 0.05]. Diclofenac was effective in revealing menstrual pain both with and without the IUD, and reduced the PI in the absence of an IUD [pre-treatment 2.39 (0.62) versus post-treatment 2.12 (0.45); P < 0.001], but had no effect when the IUD was present [pre-treatment 2.13 (0.43) versus post-treatment 2.10 (0.41)]. The results indicate that by inhibiting prostaglandin synthesis one can reduce the resistance to blood flow in the uterine arteries during menstruation. This does not hold true when an IUD is present, however, suggesting that the device might induce the production of vasoactive agents other than prostaglandins in the surrounding tissue.