Time of medication vs pregnancy stage 1. Whether pregnant or not (before implantation), it takes about 2 weeks from fertilization to implantation. During this period, it is easiest to take medicine without knowing that you are pregnant. However, during this period, the influence of drugs on embryos usually leads to embryo death or abortion, or embryo development is completely unaffected, so the use of drugs at this stage usually does not lead to teratogenesis.
2. Embryonic period (critical period, organ formation period) The second to eighth week of fetal formation is the most important period, because this is the critical moment of organ formation, and the central nervous system, heart, eyes, ears, limbs, reproductive organs, etc. are all formed at this stage, so it is also the period when drugs are most likely to cause fetal malformation, so medication should be more cautious.
3. During the fetal period from the 9th week to the full term, the influence of drugs during this period mainly lies in the growth of the fetus and the development of organ functions, and the common influences include fetal growth retardation, neural tube defects or pulmonary insufficiency. Especially in the third trimester, improper medication may lead to premature delivery.
Why should medication be graded during pregnancy? In view of this, the US FDA (Food and Drug Administration) started from 1982, requiring
Must know! The safety classification of medication during pregnancy must be known! According to the FDA's classification definition of pregnancy drugs, pregnancy drugs are divided into five levels, as follows:
Class a: safe. After a controlled study, the drug is used in pregnant women in the first three months of pregnancy, and there is no evidence that it is harmful to the fetus. For example: nystatin, etc.
Grade B: It may be proved by safe animal experiments that the drug will not harm the fetus, but there is no experience in using it on pregnant women; Or it has been proved that the drug has adverse reactions to the fetus in animal experiments, but it cannot be proved that it has adverse reactions in pregnant women's research. Such as acetaminophen, magnesium oxide, metoclopramide, etc.
Grade c: it should be avoided unless it is necessary for treatment. Animal experiments have proved that the drug can cause teratoma or fetal death, but it has not been used in pregnant women's research; Or the drug has not been used in animals or pregnant women and its effect on the fetus, so the safety is unknown. For example: cough medicine (dextromethorphan), nasal congestion relieving medicine (pseudoephedrine), expectorant medicine (acetylcysteine) and so on.
Grade D: Avoid using drugs that have definite harm and adverse reactions to human fetus unless the necessity of drug use is evaluated. For example, when there are no other effective therapeutic drugs to replace life-threatening or serious diseases, consider weighing the pros and cons and choosing drugs. For example, the third pregnancy used non-steroidal anti-inflammatory painkillers (ibuprofen, diclofenac).
X grade: teratogenicity has been proved by human and animal studies, and it is absolutely forbidden for pregnant women to use it. For example, oral drugs (isotretinoin, commonly known as acid A) for the treatment of severe acne.
Must know! Classification of drug safety during pregnancy 3 Precautions In order to give birth to a healthy baby, women of childbearing age should not be careless about drug safety during pregnancy. Once you accidentally take the medicine, stress, anxiety and even insomnia may be far greater than the influence of the medicine itself on the fetus. Therefore, it is suggested that women of childbearing age should observe the following precautions when taking medicine:
1. Make sure you are pregnant before taking medicine.
2. If you have been taking drugs for a long time while preparing for pregnancy or during pregnancy, you must discuss with your doctor or pharmacist whether it is necessary to stop taking drugs or change drugs.
3. In addition to taking the initiative to inform the doctor or pharmacist when you are sick, and taking the medicine according to his instructions, you should try to avoid using other unnecessary drugs, including Chinese patent medicines and Chinese herbal medicines, and even pay attention to supplementing extra vitamins to avoid overdose.
Education: Department of Pharmacy, Taipei Medical College. Experience: Pharmacists in the Affiliated Hospital of Taipei Medical College are currently: Younikang Pharmacist, Pharmacist Weekly of All-China Pharmacists Association/Taoyuan County reporter, National Health Insurance Home Care Pharmacist, Chairman of Community Pharmacy Committee of Taoyuan County Pharmacists Association, Pharmacist at Community Pharmacy Counseling Station of Taoyuan County Health Bureau, anti-smoking teacher of National Health Bureau, and pharmacist at Drug Abuse Prevention Counseling Station.