The effect of cocaine on myometrial contractile activity: basic mechanisms

Several clinical studies have reported an association between cocaine use in pregnancy and preterm labor. The mechanism by which cocaine exerts this effect is unclear. Although cocaine stimulates isolated myometrial contractile activity, results using whole animal models are conflicting. Although cocaine inhibits uterine neuronal and extraneuronal uptake of catecholamines and increases circulating levels of catecholamines in experimental animals, it is unlikely that facilitation of the alpha-adrenergic pathway is the sole mechanism of cocaine's action. Further investigation of possible indirect mechanisms of action including altered prostaglandin production, inhibition of beta-adrenergic response, and direct effects on intracellular calcium mobilization may lead to enhanced understanding of the clinical ramifications of cocaine use during pregnancy.