Beta-adrenergic sensitivity--imminent premature delivery.

In order to determine individual sensitivity, 0.4 microgram/kg/min of fenoterol was in fused to 95 pregnant women prior to institution of tocolytic treatment against premature delivery. Changes of maternal heart rate during this test was recorded and analysed retrospectively. The following conclusions were drawn: Even in a carefully prescreened pregnant population, 4.2% of gravidas proved to be hypersensitive to fenoterol: the irreversible commencement of premature delivery was accompanied by a significant decrease of beta sensitivity: to avoid complications due to tocolytic therapy, it is necessary to stop sympathomimetic medication in a stepwise manner: there was no pathologic consequences of fenoterol treatment to the newborn babies.