Are Dental Anesthetics Safe During Pregnancy?
We all know that whatever affects the mother can also affect her unborn child, and it’s not always apparent how an unborn child is affected until he or she is born. Many pregnant mothers strive to limit if not eliminate most risks from their environment including, in some cases, dental care.
Unfortunately, neglecting dental care can be one of the things that can adversely affect a fetus, so mothers are usually encouraged to maintain routine dental appointments if for no other reason than to monitor for oral conditions and diseases that may worsen over time. For the most part, elective dental treatment is often deferred, but there are occasions when dental treatment such as fillings or periodontal cleanings (scaling and planing) might be necessary. Depending on the severity or extent of the decay or periodontal disease, anesthetics may be indicated to ensure the patient’s comfort in the dental chair.
But you’re pregnant. And these are drugs that will be injected (local anesthetic), inhaled (nitrous oxide) or topically (benzocaine) applied to your body. Is there any risk to you or your baby?
FDA Drug Classifications and Pregnancy
The United States Federal Drug Administration classifies drugs according to the effects observed in laboratory tests on pregnant animals. From these tests, researchers can extrapolate the kind of effect these drugs could have on a human baby. You can see the description of these categories here.
Drugs such as acetaminophen (Tylenol) are classified as B drugs and considered safe for an unborn baby. Ibuprofen (Advil, Motrin) drugs are classified B in the first and second trimester, but D in the third trimester (JCDA).
As far as possible, dentists will avoid using sedation anesthetics on pregnant women, although in extreme cases it may be necessary, but usually delayed until the second trimester. It is important to note that pregnant women require a lesser dose of anesthetic (whether sedation or local or inhaled) than non-pregnant women. Don’t be afraid to double-check with your dentist and with your family physician about what levels of anesthetic would be safe and necessary to provide the level of comfort needed to complete the dental procedure.
Dentists usually have an arsenal of injectable anesthetics in their repertoire of medications. These include Articaine, Bupivacaine, Lidocaine, Mepivacaine and Prilocaine. Usually combined with these medications is a “vasoconstrictor” in the form of either epinephrine or levonordefrin. Vasoconstrictors constrict blood vessels, essentially decreasing blood flow and oxygen levels in and around the injection site. This gives the drug a time-release quality because the drug is absorbed slowly, which allows dentists to time their procedures. They can estimate with accuracy the length of time they have, for example, before they might need to administer more.
The concern with epinephrine is that “there could be a decrease in the blood supply to the placenta, spasms in the blood vessels, and spasms in the arteries that supply blood to the uterus.” (HDA) The danger, however, is only in higher doses which are classified C drugs. These include articaine, bupivacaine and mepivacaine. Lidocaine and Prilocaine are classified B drugs and are considered safe.
Nitrous Oxide and Topical Gels
Many dentists apply topical gels to an injection site prior to the injection to decrease the level of discomfort and anxiety related to injections inside the mouth. A recent FDA announcement (July 2011) warns of a connection between the use of benzocaine, the main pain-relieving ingredient in topical gels, and methemoglobinemia, which can result in greatly reducing the amount of oxygen carried through the blood. While this complication was experienced in children and is considered extremely rare, it is nonetheless concerning for a pregnant mom. There are safe analgesic gels coming out on the market after this FDA finding, and there’s nothing wrong with requesting it from your dentist or bringing your own tube along (it can be used for teething later).
Nitrous oxide or “laughing gas” may be indicated if a patient is extremely anxious, even after local anesthetic has been administered. Dentists and health experts agree that nitrous oxide should be avoided during the first trimester.
Darlene Oakley is a freelance writer for EmpowHER.com.
What is the effect of anaesthesia when pregnant? Dental Treatment Guide. Health Development Advice. Web. Mar 5, 2012.
“An Update on Local Anesthetics in Dentistry” by Daniel A. Haas, BSc, DDS, BScD, PhD, FRCD(C), Journal of the Canadian Dental Association. J Can Dent Assoc 2002; 68(9):546-51 Web. Mar 5, 2012.
Oral Health Care during Pregnancy and Early Childhood Practice Guidelines. New York State Department of Health August 2006. Web. Mar 5, 2012. http://www.health.ny.gov/publications/0824.pdf
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FDA Pregnancy Categories. University of Washington. Web. Mar 5, 2012.