Maternal thalidomide

Szabo KT, Steelman RL. Effects of maternal thalidomide treatment on pregnancy, fetal development, and mortality of the offspring in random-bred mice. Am J Vet Res 1967 28(127) 1823-8. 

In Chapter 2 the significance of the placental transfer of drugs from the maternal circulation into the fetus was discussed. At that time, the prototypic teratogen thalidomide was discussed along with several contemporary drugs such as alcohol and cocaine. By the time that thalidomide was finally removed from the market and the medicine cabinets, it had caused severe deformities in approximately 10,000 children in 46 countries. 

The typical dose-response curve for a developmental toxicant is steep and covers less than one to three orders of magnitude below the dose that kills or malforms half the embryos. However, the threshold and shape of a dose-response curve for a particular teratogen may differ, depending on the gestational time of exposure and the type of embryotoxicity that is measured. Furthermore, the dose at which an agent causes malformations may be above, below, or equivalent to the embryolethal threshold. Toxicants that cause little or no maternal toxicity, even at elevated doses, but adversely affect the conceptus are especially dangerous (e.g., thalidomide, diethylstilbestrol). 

During a 1-year period, 10 babies with major limb defects were born in Stirlingshire maternity units. At least eight of the mothers had had thalidomide prescribed in the early weeks of pregnancy (59,98-101). 

This review has so far focussed on the maternal organism as the source to the fetus of the teratogenic agent. However, the male has been implicated as the cause of a teratogenic event in animal studies for example, with methadone (106), thalidomide... 

The fear that toxic agents in the maternal environment might harm the unborn child is an ancient one that was reinforced by the thalidomide tragedy. Although toxicology and teratology are far more advanced sciences now than 20 years ago, it is still not known what factors with an adverse effect... 

Drugs and environmental chemicals Androgenic hormone Folic antagonists Thalidomide Oral anticoagulants Maternal alcoholism Combinations and interactions Unknown... 

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