Adverse effects on the fetus, course of labor, or delivery have rarely been observed when proper dosage and proper technique have been employed. Local anesthetics rapidly cross the placenta, and when used for epidural, paracervical, pudendal or caudal block anesthesia, can cause varying degrees of maternal, fetal and neonatal toxicity. The incidence and degree of toxicity depend upon the procedure performed, the type and amount of drug used, and the technique of drug administration. Adverse reactions in the parturient, fetus and neonate involve alterations of the CNS, peripheral vascular tone and cardiac function. Maternal hypotension has resulted from regional anesthesia.
Local anesthetics produce vasodilation by blocking sympathetic nerves.
Elevating the patient's legs and positioning her on her left side will help prevent decreases in blood pressure. The fetal heart rate should also be monitored continuously, and electronic fetal monitoring is highly advisable. Because many drugs are excreted in human milk, caution should be exercised when chloroprocaine is administered to a nursing mother. Restlessness, anxiety, dizziness, blurred vision or tremors may occur, possibly proceeding to convulsions. However, excitement may be transient or absent, with depression the first manifestation of an adverse reaction.