Lidocaine is a local anesthetic most commonly used during dental work and minor surgery, though it also can relieve the burning and itching caused by skin irritations. It is typically OK to use lidocaine in pregnancy when necessary, because the U.S. Food and Drug Administration (FDA) has placed it in Pregnancy Category B. This is because animal studies have shown no ill effects when used on pregnant rats, but there are not enough adequately controlled human studies to place it in the safer Pregnancy Category A. For this reason, doctors usually try to avoid using lidocaine, or even doing dental work, until the pregnancy is over.
While studies on humans are not sufficient to say whether this medication is harmful or harmless in humans, it is known that it crosses the placenta. This means that, when a woman takes lidocaine in pregnancy, her fetus will come in contact with a portion of the drug, most likely with no lasting negative effects, if animal studies are any indication. Even so, doctors may either use other numbing medications or hold off on minor surgery in pregnant women. They also may wait until the pregnancy is over to offer this drug for relief of the itchiness of skin rashes, as long as doing so will not have an adverse effect on the woman or baby.
This drug is frequently used in dental operations, so it is often recommended that dental work be delayed at least until the second trimester of pregnancy. This can make birth defects and miscarriages less likely to occur if it turns out this drug does cause problems during human pregnancies. No matter when lidocaine is used in pregnancy, it is often advisable to use as little as possible without the patient becoming uncomfortable.
There are reports that use of this drug as a local anesthetic during labor and delivery is to be avoided completely when possible. This is because studies show that newborns who have high doses of this medication in their system may be born with short-term medical conditions, such as difficulty breathing, seizures and an irregular heartbeat, though these side effects are considered quite rare. In general, though, lidocaine is rarely used during delivery unless there are no alternatives.
Breastfeeding mothers should know that this drug does enter breast milk, so they should not be prescribed lidocaine when nursing. If it is, then the mother should wait for the medication to leave her system before breastfeeding. Just like lidocaine in pregnancy, though, this drug is not known for having harmful effects on the mother or baby, so it may be used when needed. To avoid any unnecessary use of lidocaine in pregnancy or breastfeeding, women should make sure their doctor or dentist knows they are pregnant or nursing before accepting any drug prescriptions.