Regional anesthesia and postoperative analgesia procedures have been widely used in obstetric interventions in recent years. These procedures have higher side effects of local anesthetic toxicity. Systemic effects of local anesthetic drugs develop, by absorption of the drug from the injected site in a dose-dependent manner or given directly to the systemic circulation. Levobupivacaine is a local anesthetic, which is an S (-) isomer of bupivacaine. Its pharmacodynamic properties are like bupivacaine, but it is less cardiotoxic. We aimed to compare the hemodynamic measurements of rats to observe cardiotoxic effects. Cardiotoxic effects of intravenous bupivacaine and levobupivacaine infusions were studied on pregnant rats. We continued to infuse local anesthetics until the rats developed cardiac arrest. Total amount of local anesthetic infused was, 3.23±1.01 mg in the bupivacaine group and 4.17±0.75 mg in the levobupivacaine group. We observed that higher amounts of levobupivacaine were infused until cardiac arrest developed in the levobupivacaine group (p<0.05 p:0.001). Our findings demonstrate that pregnancy alters local anesthetic effects on cardiac function. We conclude that pregnancy increases the direct cardiotoxicity of bupivacaine, and levobupivacaine.