Almost impossible. Ergo, possible. It is only very unlikely.
There is a phenomenon in QM called quantum tunnelling. That is, you can actually let a particle cross an energy barrier that would be classically insurmountable. The metaphor is the one of a stone going through glass without breaking it.
I agree that a baby consists of many of those particles. So, to pass through without breaking anything is not impossible. But only ridicolously improbable. Assuming they did not use other means of extraction, obviously.
Ciao
- viole