Even when the teratogenic effect of salicylates is more theoretical than proven, its generalized use, and the existence of safer substitutes (acetaminophen) disapprove its use during the whole pregnancy. In the last trimester, aspirin increases the risk of earlier closure of ductus arteriosus, increases the time of delivery, and increases the risk of bleeding in the newborn.

Antibiotics are frequently used during pregnancy, and some of them could be toxic to the fetus: streptomycin, and tetracyclines.

Misoprostol is an anti-ulcer medication, which is being self-used to abort unwanted pregnancies. Since it is frequently ineffective, depending of the dose and/or of the period of pregnancy when it is used, an increasing number of embryos are being exposed to this drug in underdeveloped countries. This misuse obscures the assessment of its teratogenicity.

ACOG (1997) ACOG educational bulletin. Teratology. Number 223. Feb.1995. Int J Gynec Obstetr 57:81-88.