Role of adenosine in regulation of uterine blood flow during nonpreeclamptic twin gestation.

We evaluated the possible role of increased adenosine in the regulation of uteroplacental circulation during nonpreeclamptic twin gestations. We performed uterine artery Doppler velocimetry and maternal arterial blood sampling for measurement of plasma adenosine levels in 16 women with singleton gestation and 14 women with dichorionic twin gestation without preeclampsia at 11-12, 25-26 and 34-36 weeks. In singleton gestations, a negative correlation between maternal plasma adenosine levels and maternal uterine artery pulsatility index was observed. In twin gestations, there were no noticeable association between maternal plasma adenosine levels and maternal uterine artery pulsatility index. Our results suggest that the decrease in vascular resistance in twin gestations may be through the mechanisms that are independent of adenosine.