transplacental
adjective
trans·pla·cen·tal ˌtran(t)s-plə-ˈsen-tᵊl 
: passing through or occurring by way of the placenta
transplacental immunization
transplacentally
ˌtran(t)s-plə-ˈsen-tᵊl-ē
adverb 
Word History
Etymology
International Scientific Vocabulary
First Known Use
1902, in the meaning defined above
Medical Definition
transplacental
adjective
trans·pla·cen·tal ˌtran(t)s-plə-ˈsent-ᵊl
: relating to, involving, or being passage (as of an antibody) between mother and fetus through the placenta
transplacental immunization