Assuming you mean
Diagnosed while pregnant, non-invasive might wait treatment until post partum, as might very early ia, but later stages pit woman's life versus foetal life dilemma, and balance of waiting for viability.
A c-section may be needed. The cancer
itself does not pass to/infect the neonate. Ca in situ and cone or cryo might lead to miscarriage and can affect fertility
, as would rad hys & xrt.