Use of local anesthetics for dental treatment during pregnancy; safety for parturient


The majority of drugs enter the fetus’s systemic circulation through passive diffusion, though the method of transfer varies. Through a variety of active transporters on the placenta, some drugs are transferred to the fetus. Facilitated diffusion, phagocytosis, and pinocytosis are additional mechanisms for drug exchange [17]

The most frequent method of drug transfer from the mother to the fetus is passive diffusion. Drugs are transferred using a concentration gradient and without the use of energy. The concentration of the drug in the mother’s blood and the placental characteristics that influence the drug transfer determine the amount of drug transferred per unit of time. Drugs can move through water channels or the syncytiotrophoblast layer [18]

Low molecular weight, high lipophilicity, and unionized forms of drugs all benefit from passive diffusion as a mechanism of drug transfer. Because the placenta is structurally made up of lipid bilayers, drugs that are lipophilic and are not bound to proteins can freely diffuse through the placenta [19].

Passive diffusion drugs are known to adhere to Fick’s diffusion law. Diffusion rates, which depend on time, are inversely correlated with membrane thickness and directly correlated with placenta surface area and concentration gradient.

Facilitated diffusion requires carrier substances within the placenta. Facilitated diffusion does not require energy, similar to passive transfer. Cephalosporin, cephalexin, and glucocorticoids have been reported to have carrier-mediated transport systems [20,21]. However, drug transfer using facilitated diffusion is rare. In order to meet the fetus’s functional metabolic demands, facilitated diffusion is frequently used [22].

Drugs are transferred via protein pumps in the placental membrane during active transport. This transfer mechanism needs the power generated by the hydrolysis of adenosine triphosphate (ATP). It is also possible to use the energy produced by an electrochemical gradient brought on by the transmembrane movement of ions. Carriers are required for drug transfer. Carriers may reach saturation, but similar compounds do not inhibit competition. Active transporters exist in both the mother and the fetus. Drugs are transferred across the syncytiotrophoblast.

There are a few case reports of newborns of pregnant people who received lidocaine at the time of delivery experiencing side effects. These case reports describe infants who had low muscle tone (“floppy”), dilated pupils, difficulty breathing, apnea, and/or seizures that necessitated medical attention. There are also case reports where newborns who underwent deliveries while lidocaine was being used did not experience any health issues.

Every pregnancy starts out with a 3-5% chance of having a birth defect This is called the background risk. No research has been done to determine whether lidocaine increases the risk of birth defects. Studies on experimental animals and human case reports do not indicate that lidocaine would significantly increase the risk of birth defects.

OTIS/MotherToBaby encourages inclusive and person-centered language. Although mothers are still mentioned in our name, we are updating our resources to use more inclusive language. When the terms “mother” or “maternal” are used, they refer to a pregnant person. When the terms “father” or “paternal” are used, it refers to a sperm donor.

Lidocaine is a local anesthetic. Use of local anesthetics causes temporary numbness in certain body parts. Lidocaine has been administered intravenously (by IV), as a shot, and as an injection. V. ) and topically (rubbed on the body). Some over-the-counter painkilling creams and patches contain lidocaine. Lidocaine I. V. used to treat ventricular arrhythmia, an abnormal heart rhythm Injected lidocaine can also be used as a therapeutic nerve block to numb a part of the body and relieve pain, or in some medical procedures (such as the removal of an ingrown toenail).


Pregnancy increases the secretion of estrogen and progesterone, which peaks in the third trimester [14]. These hormones are known to affect liver function [15]. Prothrombin time (PT) and albumin levels can be used to gauge the liver’s capacity for synthesis. PT does not significantly change during pregnancy, but albumin levels do. Alpha-1 acid glycoprotein levels also decrease during pregnancy. As a result, unbound forms of administered drugs increase. Such an increase in drug levels causes an increase in the drug’s distribution throughout tissues and its effects.

Hepatic blood flow is known to increase 1. 5 fold during pregnancy [16]. Such alterations in hepatic blood flow may have an impact on how drugs that are primarily metabolized in the liver are metabolized. Theoretically, elevated hepatic blood flow throughout pregnancy could lessen drug bioavailability by raising drug clearance.

Pregnancy-related increases in bile acid levels are known to cause sub-clinical cholestasis. An increased gallbladder volume during fasting and an increased residual volume following contraction are both visible on ultrasound. However, these symptoms are uncommon and, when they do, they go away after delivery, so they typically do not present serious clinical issues.

The placenta serves as a link between the mother and the fetus. Through the placenta, nutrients are transferred to the fetus, and waste products created by the fetus’ metabolic processes are transferred to the mother for excretion. Drugs given to pregnant women during pregnancy may have an impact on the fetus after crossing the placenta. Understanding how drugs are transferred from the mother to the fetus requires knowledge of the placenta’s structure and function.

The placenta, a vital organ with a disc shape that connects the mother and the unborn child physically, The chorionic villi are the placenta’s most fundamental structural component. The chorion, or outermost fetal membrane, contains vascular structures called villi. The maternal and fetal blood vessels are located in the intervillous space, which is the area between the villi and has a significant cavernous structure. The blood vessels of the mother’s uterus enter the intervillous space at week eight (gestational age), which is large enough to hold 400–500 mL of blood. The placenta transmits gases, nutrients, and medications given to the mother to the fetus. Basically, maternally administered medications can pass from the mother to the fetus and have an impact on the fetus.


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