Abstract
Arrest of imminent premature labour by β-adrenergic stimulation often fails, due to undesirable side effects or lack of effectiveness. Inhibition of oxytocin release from the neurohypophysis by ethanol also has disadvantages.
α-adrenergic stimulation in pregnant and non-pregnant women increases uterine contractions, while blocking of α-receptors in non-pregnant patients has been shown to reduce uterine activity. A combination of adrenergic α-blockade followed by β-stimulation therefore might be more effective than β-stimulation alone in the treatment of premature labour.
This combined regimen was used in 6 women at 16–20 weeks of pregnancy. The response to oxytocin-induced uterine contractions was measured.
In mid-pregnancy, blockade of α-receptors did not reduce oxytocin-induced activity, β-stimulation reduced the uterine activity; this reduction seemed to be independent of α-blockade.
The combination of α-blockade and β-stimulation did not seem to be superior to β-stimulation alone.