Tritiated water exchange in the human uterine cavity

Measurements with the use of tritiated water (3H2O) in human volunteers indicate that the mean tritiated water half life (t1/2 3H2O) in the uterine cavity is 1.3 minutes. This figure is very close to that previously measured in subhuman primates. By extrapolation from various prior studies the volume of the human uterine cavity (aVc) may be assumed to approximate 0.4 to 0.6 ml. According to the formula aVc divided by 2 x 1,440 divided by (t1/2 3H2O) water turnover in the human endometrial canal is calculated to range from 222 to 332 ml/24 hours.