[Beta-mimetics and Pourcelot's index]

In a series of 20 patients presenting a threat of premature delivery, the vascular resistance index of Pourcelot, in the umbilical artery, was measured before, and then 24 hours after starting a continuous Salbutamol perfusion. A moderate but significant decreased placental vascular resistances is noted under betamimetic treatment. Relaxation of the myometrium obtained with a tocolytic treatment could be implicated in this alteration of placental resistances.