Patient: description of disease (onset time, main symptoms, hospitalization, etc.): I had my period on June 12-16, took 18 tablets of erythromycin, 12 tablets of ibuprofen, and 12 tablets of morinoguanidine hydrochloride on July 10 and 11, and found out that I was pregnant on July 13 when I checked. Do these drugs have any effect on the fetus? Obstetrician and gynecologist: The effect of drugs on the fetus is determined by factors such as the type of drug, dosage, gestational age, and the sensitivity of the fetus to the drug. There are several ways to categorize the safety of drugs used by pregnant women during pregnancy, among which the standards formulated by the U.S. Food and Drug Administration (F D A) are widely accepted by doctors in various countries because of their clear meaning and scientific objectivity.The F D A categorizes the safety of drugs into five categories, namely, A, B, C, D, and X. Some drugs are categorized into two different risk classes, one for commonly used dosages and the other for overdosages. A: No risk to the fetus has been shown in early pregnancy in women with controls (and no evidence of risk in middle and late pregnancy), and there may be minimal harm to the fetus. B: no risk to the fetus in animal reproduction tests but no control group of pregnant women, or side effects (less severe than infertility) in animal reproduction tests but not confirmed in a control group of early pregnant women (and no evidence of risk in intermediate or late gestation). C: Side effects on the fetus (teratogenicity or embryonic lethality or other) have been demonstrated in animal studies, but there is no control group in women or no available information in women and animal studies. Drugs are given only when the benefits to the fetus are weighed against the risks. D: Risk to the human fetus for which there is positive evidence, but which, despite its harmfulness, requires positive confirmation of benefit to the pregnant woman for its application (e.g., in cases of life-threatening or severe disease that precludes the application of a safer drug or when the drug is ineffective). X: The drug has been shown in animal or human studies to cause fetal abnormalities or is known to be dangerous to the fetus based on human experience, is harmful to humans or to both, and the risks of the drug clearly outweigh any benefits when applied to a pregnant woman. The drug is contraindicated in women who are or will be pregnant. There are very few drugs of class A. Vitamins belong to this class, such as the various vitamins B and C. There are not many B-rated drugs either, but happily all antibiotics used on a daily basis fall into this category. For example, all penicillins and the majority of cephalosporins are class B drugs, commonly used ampicillin, cephradine, cefotrizine (trade name: Mycobacteria or Rocephin) and cefotaxime (trade name: Fudaxin) used for the rescue of serious infections are all class B drugs. In addition, Zeomicin, Clindamycin, Erythromycin and Furotoxin are also class B drugs. Among the commonly used antipyretic and analgesic drugs, indomethacin (anti-inflammatory), diclofenac (fitalin), and ibuprofen (fenbendazole) are class B drugs. There are more drugs in the C class. These drugs have either not been available for a long time or have been used less frequently in pregnant women, and it is difficult to draw firm conclusions about whether or not they may cause fetal harm, mainly in early pregnancy. The clinic is still waiting for more reports to confirm their harmlessness. Caution should be exercised in the use of class C drugs. Antiviral drugs, most of which belong to class C, such as acyclovir. I.e., morpholinoformin hydrochloride (viroxicam), acyclic guanosine (acyclovir), and zidovudine (zidovudine), which is used in the treatment of AIDS disease. The following points of attention are suggested for the use of medication during pregnancy: (1) For the use of medication during pregnancy, avoid multiple drug prescriptions and choose Class B drugs whenever possible. (2) Don’t just think about the medication, but focus on the disease, which can pose additional risks to both the mother and the fetus. (3) It is not only drugs that can be teratogenic, but also various other teratogenic possibilities. (4) It is important to note that early pregnancy is the stage of differentiation of fetal body parts and organs, and drug teratogenesis is likely to occur at this stage, especially at 3 to 8 weeks of gestational age, i.e., 5 to 10 weeks of gestational age. The safety of medication in middle and late pregnancy increases. Certain drugs, such as ethanol, are harmful to the fetus, especially the nervous system, throughout the entire stage of pregnancy.