THALIDOMIDE, A CURRENT TERATOGEN IN SOUTH-AMERICA

Thalidomide, mainly used for the treatment of leprosy, is a current te ratogen in South America, and it is reasonable to assume that at prese nt this situation is affecting many births in underdeveloped countries . Moreover, the potential re-marketing of thalidomide for the treatmen t of a large variety of diseases may extend the problem to the develop ed world. When the drug is available, the control of its intake during early pregnancy is very difficult since most pregnancies are unintend ed. The ongoing occurrence of thalidomide embryopathy cases went undet ected by the ECLAMC, due to several factors: (1) low populational cove rage through this monitoring system; (2) pre-existence of the teratoge n with its effects present in both baseline (expected) and monitored ( observed) materials; and (3) lack of a defined phenotype to be monitor ed. Thus, if thalidomide re-enters the market throughout the world, du e to the wide range of new applications, occurrence of phocomelia alon e might not be sufficient to detect its effects. By a case-reference a pproach, the ECLAMC registered 34 thalidomide embryopathy cases born i n South America after 1965 whose birthplaces correspond to endemic are as for leprosy. Phocomelia was found in five of eleven fully described cases. Thus, phocomelia alone is neither specific nor sufficient to s erve as a suitable phenotype to survey the teratogenic effects of thal idomide. Therefore, a thalidomide-like phenotype, defined as any bilat eral upper and/or lower limb reduction defect of the preaxial and/or p hocomelia types, should be included in the routine surveillance of bir th defects in all programmes. (C) 1997 Wiley-Liss, Inc.