1) Placental 
Transplacental refers to the ability of a toxin or pathogen to cross the physical and biological barriers of the placenta separating the mother and fetus, to whom such substances may be dangerous. This would include, for example, HIV and the drug thalidomide. if the agent cross placenta and damage genetic material known transplacental genotoxin .....
Crossing the placenta. ... (05 Mar 2000) ... 
(trans″plә-sen´tәl) through the placenta.
Type: Term Pronunciation: trans′plă-sen′tăl Definitions: 1. Crossing the placenta.
[adj] - through or by way of the placenta
adjective occurring through or by way of the placenta; `transplacental passage of nutrients`
Transplacental means crossing the placenta. The placenta is the in-utero connection between the mother and the fetus. Transplacental means something (a drug, antibodies, an infectious agent, etc.) crosses from the mother to the fetus before birth. This can be good in the case of antibodies that protect the newborn from disease early in life or bad ...