Introduction In clinical practice, we often encounter maternal infectious diseases that require the use of antibiotics. Many young clinicians have no idea what anti-infective drugs can and cannot be used at this time. So this article will talk about this problem, hope to help you. To understand this part of the content, it is necessary to be familiar with the FDA on maternal medication grading standards. In the clinic, we often encounter maternal infectious diseases that require the use of antibiotics. Many young clinicians have no idea at this point in their minds as to which anti-infective drugs can be used and which cannot. So this article will talk about this problem, hope to help you. To understand this part, it is necessary to familiarize yourself with the FDA’s grading standards for maternal medications. FDA grading standards on drugs in pregnancy The U.S. Food and Drug Administration according to the teratogenicity of drugs to the fetus, the harm level of drugs to the fetus is divided into A, B, C, D, X 5 levels: Class A: in human studies with a control group, proved to be no harm to the fetus. Includes multivitamins, vitamin preparations during pregnancy, but excludes high-dose vitamin preparations. Class B: No harm to the fetus has been demonstrated in animal studies, but no studies in humans are available; or an adverse effect has been demonstrated in animal studies, but this effect has not been found in studies in humans with good control groups. Category C: no good animal studies or studies in humans are available, or adverse effects on the fetus have been demonstrated in animal studies, but there is a lack of available information in humans. Many drugs commonly used in pregnancy fall into this category. Category D: There is evidence of harm to the fetus, but the advantages and disadvantages should be weighed during pregnancy, and when the advantages outweigh the disadvantages, they can still be used. For example, phenytoinna and carbamazepine. Category X: The risk to the fetus has been shown to significantly outweigh any benefit. For example, isotretinoin, which is used to treat acne, can cause a variety of malformations in the fetal central nervous system, face and cardiovascular. 1, antibiotic drugs: ① penicillin: B class drugs, less toxic, is the safest anti-infective drugs for pregnant women, including broad-spectrum penicillin such as ampicillin, piperacillin, meloxicillin and other β-lactam preparations. ② Cephalosporins: Class B drugs. Such drugs can pass through the placenta, but there are no reports of teratogenicity of such drugs, plasma half-life in pregnancy is shorter than non-pregnancy. Available during pregnancy. Aminoglycosides: Class D or C drugs. This kind of drug is easy to pass through the placenta, umbilical blood drug concentration increased significantly, pregnant women and fetuses have some harm, pregnancy is prohibited or used with caution. Macrolides: mostly class B, due to large molecular weight, not easy to pass through the placenta. It can be used for penicillin allergy and chlamydia, mycoplasma infection. ⑤ Tetracyclines: mostly class D, including tetracycline (D), oxytetracycline (D), doxycycline (D), memantine (D) and so on. These drugs can easily pass through the placenta and into breast milk and are teratogenic. Tetracycline fluorescent substances can be deposited in tooth enamel and fetal bones, affecting fetal tooth enamel and physical development, leading to intrauterine growth retardation. When pregnant women with renal insufficiency, it can cause acute fatty liver in pregnant women, and is prohibited during pregnancy. The concentration of these drugs in breast milk is high, breastfeeding need to weigh the pros and cons of using or suspend breastfeeding. (6) Chloramphenicol: it can pass through the placenta and enter the breast milk, it has inhibitory effect on bone marrow, and it can cause “gray baby syndrome” when used in preterm infants. It is prohibited during pregnancy and lactation. Quinolones: mostly class C drugs, including piperidol, haloperidol, ciprofloxacin, ofloxacin, sparfloxacin, etc. The mechanism of action of these drugs is to inhibit the DNA of bacteria. The mechanism of action of such drugs for the inhibition of bacterial DNA helicase, such drugs have a strong affinity for bone and cartilage, can cause irreversible arthropathy in animals, or affect the development of fetal cartilage, prohibited during pregnancy. ⑧ sulfonamides: mostly class C, this type of drug is easy to pass through the placenta, animal experiments have a teratogenic effect, but there is no report in humans. Application in late pregnancy can make the newborn thrombocytopenia, hemolytic anemia. It can also competitively inhibit the binding of bilirubin to albumin, causing neonatal hyperbilirubinemia. Use with caution during pregnancy and prohibited before delivery. ⑨ Jejamycin class: including Jejamycin, clindamycin, etc., is a class B drug. Can pass through the placenta and into the milk, no record of adverse effects on the embryo, relatively safe. ⑩ Metronidazole: now class B, used to be categorized as class C. There are reports of 1700 cases of early pregnancy in women after the application did not increase the rate of teratology, and recently the FDA has classified it as a class B drug. The CDC has recommended its use in the treatment of vaginal trichomoniasis during pregnancy. However, tinidazole is a class C drug, used with caution during pregnancy. Ornidazole: no teratogenicity in animal experiments, but there is no controlled study in pregnant women, use with caution 2, antiviral drugs: ① virus azole: that is, triazolyl nucleoside, for the X class of drugs, animal experiments have found that almost all kinds of test animals after the application of the product, there are teratogenicity and embryonic killing effect, pregnancy is prohibited. The elimination of this product in the body is very slow, four weeks after stopping the drug can not be completely cleared from the body. Acycloguanosine: Acyclovir, a class B drug. This product can inhibit DNA synthesis, used for herpes virus infection. It has been reported: 581 cases of pregnancy with this drug, the incidence of malformations did not increase. Wan Nai Luo Wei: Class B; Ganciclovir: Class C ③ Interferon: it is best not to use during pregnancy ④ Lamivudine, Zidovudine: it is Class C, and it can be used for the treatment of AIDS during pregnancy. 3, anti-tuberculosis drugs: ① isoniazid: Class C drugs. This drug has high lipid solubility, low molecular weight, and hardly binds to plasma proteins, so it is easy to pass through the placenta, and the concentration in umbilical cord blood is higher than that in maternal blood. However, a retrospective analysis of 4900 pregnant women using isoniazid showed no increase in the rate of fetal malformations, and it is now believed that pregnancy with tuberculosis can be used. ② Rifampicin: Class C drug. Animal experiments found that the application of RFP to pregnant rats and mice, the fetus can develop spina bifida and cleft palate. However, it has been reported that in 204 cases of patients using rifampicin during pregnancy, the rate of neonatal malformations did not increase. It is a cautionary use during pregnancy. However, the concentration of the drug in breast milk is low, and it can be used during lactation. Ethambutol: Class B drug. It is currently believed that this product has no teratogenic effect on humans, and is preferred during pregnancy when suffering from tuberculosis. 4, antifungal drugs: mycotoxin and clotrimazole, are class B drugs, available during pregnancy; miconazole, fluconazole for class C drugs; dicotyledonin B for the treatment of systemic mycobacterial infections, did not see an increase in congenital malformations reported. Itraconazole (C) lacks studies in early human pregnancy, use with caution during pregnancy. High doses of fluconazole can cause fetal malformations in animals, but no human pregnancy teratogenicity has been reported.