Effects of sympathomimetic tocolytic agents on the fetus

The variety of factors controlling the onset of parturition, äs well äs the very complex mechanisms which physiologically maintain pregnancy by inhibiting uterine contractions are only partially understood today.As long äs the triggering mechanisms, and the conditions favoring timely and early labor are incompletely known, symptomatic therapeutic attempts aim at blocking unwanted contractile activity of the uterine smooth muscle fibres.The high rates of neonatal mortality and morbidity associated with premature births [52] have stimulated efforts to find agents which safely inhibit uterine contractions in humans. Inhibition of uterine activity by /?-mimetic agentsA theoretic basis has been provided by AHL-QUIST'S [2] concept of adrenergic