Sterile like having no bacteria on them at all? Yes, but not for long.
A baby born by Caesarian section is sterile for the first few seconds until bacteria from the air start to fall on it. A baby born vaginally gets smeared with bacteria on the way out (and it seems that they are usually a friendlier set of bacteria than you’d find in the air of a hospital).
People with severe combined immunodepression, or people undergoing some kinds of cancer treatment, need to live in sterile plastic bubbles because they have no way to defend themselves against germs.
It’s very difficult to keep anyone sterile in the long term, so most patients have a bone marrow transplant to repair their immune systems as soon as possible.
In short, yes. Many couples need IVF (in-vitro fertilisation) in order to have babies. This involves artificially fertilising the eggs in a lab and implanting them into the mother once they have begun dividing.