Pregnancy category

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The pregnancy category describes drugs with regard to their risk of causing damage and deformities to the fetus when used during pregnancy .

Drug treatment of pregnant women and mothers during breastfeeding can be a major problem, depending on the drug, and should be carried out with appropriate caution and critical examination. Most drugs cross the placenta and pass into breast milk . Some drugs can harm the child, others have (so far) not shown any teratogenic effects in extensive studies .
The best-known case of a teratogenic effect became public in the early 1960s: through the use of the sleeping pill thalidomide (Contergan ® ) during pregnancy, more than 10,000 children were born in Germany, some with severe malformations. When it was launched on the market in the late 1950s, the drug was classified as particularly safe, as no fatal side effects occurred in animal experiments even after a tenfold overdose . Possible teratogenic properties had not been investigated. As a result of the so-called Contergan scandal , strict regulations were created in many countries for the safe use of drugs, which also take into account the protection of unborn life.

Even without taking medication during pregnancy, the spontaneous rate of child malformations is around 3%. If such complications arise during drug therapy for the mother, it is difficult to distinguish possible (rare) drug effects from spontaneous malformations. Therefore, no drug can be considered 100% safe for use during pregnancy. Nevertheless, drug therapy is necessary and useful for serious illnesses in pregnant women, despite possible side effects for unborn life.

Germany: Risk groups for use in pregnancy

The “ Red List ” drug directory, which is widely used in Germany, uses a code system for eleven risk groups in the drug treatment of pregnant women.

category description
Gr 1 When used extensively on humans, there was no suspicion of an embryotoxic / teratogenic effect. The animal experiment also gave no indications of embryotoxic / teratogenic effects.
Gr 2 When used extensively on humans, there was no suspicion of an embryotoxic / teratogenic effect.
Gr 3 When used extensively on humans, there was no suspicion of an embryotoxic / teratogenic effect. However, the animal experiment produced indications of embryotoxic / teratogenic effects. These seem to be of no importance to humans.
Gr 4 Sufficient experience with the use in humans is not available. The animal experiment did not produce any indications of embryotoxic / teratogenic effects.
Gr 5 Sufficient experience with the use in humans is not available.
Size 6 Sufficient experience with the use in humans is not available. The animal experiment produced indications of embryotoxic / teratogenic effects.
Size 7 There is an embryotoxic / teratogenic risk in humans (1st trimester ).
Size 8 There is a foetotoxic risk in humans (2nd and 3rd trimester).
Size 9 There is a risk of perinatal complications or harm in humans.
Gr 10 There is a risk of undesirable hormone-specific effects on the fruit in humans.
Gr 11 There is a risk of mutagenic / carcinogenic effects.

Notes on the ciphers listed above:

Chiffren Gr 1 – Gr 3 : Medicines, of which it can be assumed with a probability bordering on certainty that they were taken by a large number of pregnant women, without any evidence of an increased rate of malformations or other clinically relevant consequences for would have resulted in the embryo. The principle that drugs should generally only be used during pregnancy, especially in the 1st trimester, if there is a strict indication, taking into account the risk for mother and child, is taken into account by manufacturers who state restrictions during pregnancy and this with Gr 1 – Gr 3 justify.
Codes Gr 4 – Gr 6 : Medicines which are assumed to have been taken by only a small number of pregnant women, but which, according to previous experience, did not cause an increased rate of malformations or other serious consequences for the embryo. These include B.
  • Medicines that have only been on the market for a short time
  • Medicines whose range of indications excludes use in a large number of pregnant women.
Code Gr 7 : “Embryotoxic” is understood to mean the sum of all direct and indirect effects on the embryo that can cause malformations, other permanent damage or death.
Code Gr 8 : “Foetotoxic” is understood to mean the sum of all direct and indirect drug effects on the fetus. These can be temporary (e.g. electrolyte disturbances from diuretics) or permanent (e.g. tooth discoloration from tetracyclines). As an indirect disorder z. B. to consider a reduced blood flow to the placenta.
Code Gr 9 : “Perinatal complications or damage” is understood to mean drug effects that influence the birth process or cause damage to the fetus / newborn (e.g. uterine-contracting effect due to ergot alkaloids, increased bleeding due to prostaglandin synthesis inhibitors, jaundice neonatorum due to sulfonamides).
Code Gr 10 : This category applies in particular to sex hormones (e.g. masculinization of female fetuses with androgens and synthetic gestagens ). These specific hormone effects are not classified under code Gr 7 or Gr 8.

USA: Pregnancy Category (PRC)

The American authorities Food and Drug Administration (FDA) in 1979 with the Pregnancy [risk] Categories (PRC), a system for risk assessment of fetal damage caused by drugs presented which today is used worldwide. The FDA divides drugs into five risk categories:

category description
PRC A Appropriate and controlled studies have shown no risk to the fetus in the first trimester (and there is no evidence of risk in later trimesters).
PRC B Animal reproductive studies have shown no risk to the fetus, but there are insufficient or no studies of fetal risk in humans.
PRC C Side effects on the fetus have been observed in animal experiments ; there are insufficient or no studies on the risk in humans. However, the potential benefits of the drug may justify its use during pregnancy, despite the potential risks.
PRC D By evaluating side effects, market observations or clinical studies, indications of a risk for the human fetus could be secured. However, the potential benefits of the drug may justify its use during pregnancy, despite the potential risks.
PRC X Through animal experiments or evaluations of side effects, market observations or clinical studies on humans, indications of a risk or malformations in the human fetus could be secured. The risks of using it during pregnancy clearly outweigh the potential benefits.

Australia: ADEC Pregnancy Category Definitions

In Australia , a commission of the Australian Drug Evaluation Committee (ADEC) has issued the ADEC Pregnancy Category Definitions, a system comparable to the American system, which only differs slightly in a few points:

category description
PRC A Active ingredient taken by many pregnant / childbearing women, no accumulation of malformations (or similar) known.
PRC B1 Active ingredient taken by some pregnant / childbearing women, no accumulation of malformations (or similar) known. No risk according to animal experiments.
PRC B2 Active ingredient taken by some pregnant / childbearing women, no accumulation of malformations (or similar) known. Animal experiments inadequate, but show no risk.
PRC B3 Active ingredient taken by some pregnant / childbearing women, no accumulation of malformations (or similar) known. Animal experiments show increased risk, transferability to humans unclear.
PRC C Damage (possibly reversible) to the fetus / newborn is known or suspected, but no malformations. Specific information required before use.
PRC D Known or suspected deformities or irreversible damage to the fetus / newborn. Specific information required before use.
PRC X absolute contraindication.

Examples

Drugs with known teratogenic effects:

literature

  • Ch. Schaefer, H. Spielmann, with the collaboration of K. Vetter: Medicinal prescription in pregnancy and lactation . 6th edition. Urban & Fischer Verlag, Munich 2001
  • Rote Liste® Service GmbH (publisher), ROTE LISTE® 2006, ISBN 3-939192-00-7 , scope: 2208 pages
  • R. Sannerstedt, P Lundborg et al .: Drugs during pregnancy: an issue of risk classification and information to prescribers . In: Drug Safety . tape 14 , no. 2 , 1996, p. 69-77 , PMID 8852521 .

Web links

Individual evidence

  1. ↑ Medicines during pregnancy and breastfeeding .  ( Page no longer available , search in web archives )  Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. (PDF) Red List; Retrieved April 8, 2013@1@ 2Template: Toter Link / www.rote-liste.de  
  2. ^ FDA Drug Bulletin 1982; -25.