[Serum myoglobin in pregnant women treated with tocolytics and carnitine]

Forty-two pregnant women threatened by miscarriage or premature delivery have been studied. A group of 21 gravidas was treated with ritodrine and potassium chloride. The treatment protocol of another group of 21 gravidas included carnitine (2 g infusion with phleboclysis). It was thus observed that the haematic concentration of myoglobin increases about twice by comparison with normal values during i.v. tocolytic treatment whereas tocolytics per os do not affect the blood level of myoglobin (phenomenon observed in another group of 10 gravidas also suffering from threatened miscarriage or premature delivery). The use of beta 2-mimetics involves the onset of at times serious side-effects and methods have been sought to anticipate and prevent them. Measurement of serum myoglobin is intended as a useful investigation for monitoring tocolytic therapy which, as a result of its myotoxicity in the cardiac and skeletal musculature demands extremely cautious use. Moreover, the use of carnitine did not modify the blood concentration of myoglobin, whereas it obtained beneficial results on the onset of beta 2-mimetic induced side-effects.