Can pregnant women take antibiotics?
For pregnant mothers, taking medicine is a major event, and antibiotics are the most scrupulous medicine for pregnant mothers. Not to mention drug resistance, it is teratogenic to the fetus is enough to make pregnant mothers retreat.
No, a related article was published on "BMJ" not long ago. This article evaluated the use of macrolide antibiotics during pregnancy with severe malformations, cerebral palsy, epilepsy, hyperactivity and The relationship between autism spectrum disorders [1]. The results of
showed that compared with penicillin, mothers who used macrolide antibiotics in the first trimester of pregnancy had a higher risk of major birth defects, especially cardiovascular malformations. .
One side is the "great" harm of antibiotics to the fetus, and the other side is the disease that may worsen without antibiotics. How to choose?
In fact, there are many types of antibiotics, and different antibiotics have different effects on the fetus. When infectious diseases occur, doctors will choose safer antibiotics based on the treatment of the disease.
FDA (U.S. Food and Drug Administration) According to the risk of drugs to the fetus, drugs are divided into 5 categories. At present, this set of standards is adopted in our country. [2].
Let’s take a closer look~
The most commonly used antibiotics during pregnancy
The most commonly used and safer antibiotics during pregnancy[4]There are 3 categories ：
1. Penicillins
belongs to category B, has little toxicity to the human body, does not cause fetal malformations, and has little effect on the liver and kidney functions of pregnant women. It is safe to use during pregnancy. The most commonly used antibiotics for pregnant women. The main adverse reaction is allergic reaction.
Commonly used drugs include ampicillin, amoxicillin, penicillin V potassium, mezlocillin, piperacillin, etc.
2. Cephalosporins
belongs to the B category, currently widely used antibiotics in clinical, non-teratogenic, less impact on the fetus and newborn. Compared with penicillin, it is less resistant to resistance and has fewer allergic reactions.
Commonly used cefazolin, cefuroxime, cefoperazone, cefotaxime, ceftriaxone, ceftazidime, etc.
3. erythromycin, roxithromycin, azithromycin, lincomycin, clindamycin
belongs to category B, has little effect on fetuses and newborns, usually as penicillin allergic Alternative medicines can be considered when indicated by medicines.
Other drugs used with caution or prohibited during pregnancy
1.Aminoglycoside
has no teratogenic activity, but has damage to the auditory nerve and renal function of the fetus, causing it The incidence of neonatal vestibular damage and congenital deafness is 3%-11%. It should be used with caution or contraindicated during pregnancy.
Commonly used drugs: gentamicin, kanamycin, and amikacin are class C drugs, streptomycin and tobramycin are class D drugs.
2.Nitroimidazole
Animal experiments have proved that this type of drug may cause teratogenic and carcinogenic effects. It has not been confirmed that it has this effect on humans.
Representative drug: Metronidazole is a class B drug. At present, the use during pregnancy is controversial, and most advocates not to use it lightly in early pregnancy, and can be used when there are indications in the middle and late pregnancy, but topical medication should be the main topic.
Tinidazole is a class C drug, and its safety during pregnancy has not been fully evaluated, so use it with caution during pregnancy.
3.Quinolones
can affect fetal cartilage development through the placenta, which may potentially cause neonatal joint disease, so it should not be used during pregnancy.
Commonly used are norfloxacin, ofloxacin, levofloxacin, ciprofloxacin, etc., all of which belong to category C.
4.Sulfonamide
Taken before delivery, it can pass through the placental barrier and cause neonatal hyperbilirubinemia, hemolytic anemia and kernicterus. Therefore, use it with caution during pregnancy, late pregnancy or before delivery Disabled.
Representative drugs: Sulfadiazine is classified as Class B/X in the FDA classification, and sulfamethoxazole is classified as Class C. Compound sulfamethoxazole may have teratogenic effects and should not be used during pregnancy.
5.Tetracycline
Typical fetal malformation drugs, use in early pregnancy can cause fetal limb dysplasia or small limb malformations, use in the middle and late pregnancy can cause damage to maternal liver and kidney function, and fetal growth Limited to dysplasia of fetal enamel, fluorescent substances are deposited in enamel and bone. Therefore, it should be disabled throughout pregnancy.
Commonly used are tetracycline, oxytetracycline and doxycycline, all of which belong to class D drugs.
6.chloramphenicol
is a class C drug, which has the risk of liver damage and neutropenia to pregnant women. It can enter the fetus or newborn through the placenta. The imperfect liver enzyme system in infants causes drug accumulation, leading to severe bone marrow suppression and "gray baby syndrome" in newborns, which manifests as cyanosis, dyspnea, vomiting, anorexia, abdominal distension, and then circulatory failure. The neonatal mortality rate is high. Therefore, it should not be used during pregnancy.
7.Erythromycin ester
can cause intrahepatic cholestasis and liver parenchymal damage in pregnant women, causing elevated transaminase, hepatomegaly and obstructive jaundice, etc. This class of drugs during pregnancy Avoid application. Such as relying on erythromycin (odorless erythromycin), erythromycin ethylsuccinate and so on.
8.Anti-tuberculosis drug
ethambutol
is a class B drug, which has teratogenic effects in animal experiments. Although it has not been confirmed in humans, the use during pregnancy still needs to be fully balanced Pros and cons.
rifampicin
belongs to class C drugs, animal experiments have teratogenic effects, so pregnant women within 3 months of pregnancy are prohibited.
Isoniazid
is a class C drug, which can pass through the placental barrier. No obvious teratogenic effects have been found so far, but its metabolite isoniazid acetate interferes with the metabolism of vitamin B6 and can cause neonatal encephalopathy , Seizures or mental retardation, so it should be used with caution during pregnancy.
9.Antifungal
Clotrimazole and Nystatin
belong to class B drugs. When externally used to treat vulvovaginal candidiasis in pregnant women, the amount of vaginal absorption is very small. No adverse effects on the fetus have been found, and it can be applied topically during pregnancy.
Miconazole
is a category C drug of the FDA, but it is used for vaginal administration and the absorbed amount is very small. It can be used with caution in the middle and late stages of pregnancy.
Other antifungal drugs
such as ketoconazole, itraconazole, fluconazole, griseofulvin, amphotericin B, etc. can pass through the placenta. Animal experiments have confirmed teratogenic effects. It can cause severe liver and kidney damage and bone marrow suppression in newborns. It is a class C drug and should be avoided during pregnancy.
10.Antiviral drugs:
Oseltamivir, zanamivir, and peramivir, all belong to class C drugs. No serious adverse reactions to pregnant women and fetuses have been found. When the benefits outweigh the disadvantages, it can be considered for pregnant women.
Ribavirin is a class X drug, which has a strong teratogenic effect and is toxic to mothers and children. It is contraindicated during pregnancy.
The effect of antibiotics on the fetus is not only related to the nature of the drug itself, but also closely related to the number of weeks of pregnancy at the time of administration.
Within 2 weeks of pregnancy, the effect of the drug on the embryo is "all or nothing", either abortion or unaffected, not teratogenic.
The 3rd to 8th week of pregnancy is a key stage of embryonic development and a highly sensitive period for teratogenicity. At this time, if the mother-to-be is not suitable to seek medical treatment in time, she must not take the medicine privately.
9th week of pregnancy-childbirth, it is the stage of fetal growth, organ development, and functional perfection. Only the nervous system, reproductive organs and teeth continue to differentiate, especially the development of the nervous system reaches its peak in the third trimester. Medication can easily cause central nervous system, liver and kidney toxicity, etc. [5].
In short, although there are many antibiotics, they must not be used blindly. It is best not to use them when they are available or not. When you must use them, you must follow your doctor's advice and take safer antibiotics during pregnancy.
References:
[1] Associations between macrolide antibiotics prescribing during pregnancy and adverse child outcomes in the UK: population based cohort study.[J] .BMJ, 2020, 368: m766.
[2] Xie Xing. Obstetrics and Gynecology 9th Edition. People's Medical Publishing House.
[3] "Guiding Principles for Clinical Application of Antibacterial Drugs" Revised Working Group. Guidelines for Clinical Application of Antimicrobial Drugs (2015 Edition) )[S].Beijing: People's Medical Publishing House,2015.
[4] An Ruifang, Gou Wenli. Reasonable application of antibiotics during pregnancy and lactation[J]. Chinese Journal of Practical Gynecology and Obstetrics, 2012, 28( 07):500-503.
[5] Chen Hongmei. The effect of pregnant women's medication on the fetus[J].Electronic Journal of General Stomatology,2019,6(21):17.
First issue: Medical Obstetrics and Gynecology Section channel
author: small fan
Editor: Liu Fengling
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