Yes and eventually they will realize that they have a biological child that they will never be able to see and the reason is because at some point in their lives they thought that several thousand dollars would be the answer to all of their problems.
The most sickening thing I ever hear judicially are the cases where a couple adopts a baby, and then 4 years later, the biological "sperm donor" (shmuck who screwed the angel who gave up her baby rather than kill it) finds out he fathered a child, and some contemptible judge REMOVES the child from his loving PARENTS and awards custody to the LOW LIFE bio-"father" simply because he did not know he had impregnated the bio-mother.
"Yes and eventually they will realize that they have a biological child that they will never be able to see"
There is no guarantee that the donated egg will be successfully fertilized, much less successfully implanted via IVF, much less successfully carried to term.
Chances of all those actually occurring are slim.