ver two-thirds of women consume drugs during pregnancy, and approximately half of pregnant women did not plan to become pregnant, so in the early and most sensitive period of fetal development exposure to numerous drugs often occurs. Drug manufacturers do not test drugs on pregnant women because it is considered unethical, so the assessment of the potential risks of using the drug for the mother and the unborn child is based on studies conducted on animals, men and women who are not pregnant, on the effects of other drugs with similar pharmacokinetic properties that have known side effect, on the data on the use of drugs by pregnant women before they knew they were pregnant or had an indication for the use of the drug despite the risk, and on the registries of pregnancies and birth defects. According to the above data, the FDA developed a classification of the risks of using certain drugs during pregnancy as early as 1979, and in 2015 the categories were replaced by narrative descriptions related to risks in pregnancy, childbirth, breastfeeding and risks to the reproductive system of men and women. The impression that the placenta forms an impermeable barrier to drugs is now widely considered a misconception. It has been shown that almost all drugs administered during pregnancy enter the fetal circulation to some extent. Negative effects of drug exposure during pregnancy can manifest as pregnancy loss, teratogenicity, fetotoxicity, side effects in the newborn and delayed side effects in the developing child. The most commonly used drugs in nursing mothers are relatively safe for infants. The dose of the drug received by the infant through breast milk is generally small and much lower than the known safe doses normally given to newborns and infants. Harmful effects after exposure to drugs from breast milk are mostly immediate, such as sedation and irritation of the infant and gastrointestinal complaints. Over 50% of women use analgesics during pregnancy, 50-80% of pregnant women suffer from nausea, about 50% also from vomiting, and almost a quarter of women receive antibiotics during pregnancy therefore, pharmacological therapy is often an indispensable part of pregnancy and breastfeeding.