Fun fact: Paternity testing is illegal in France to protect women who engage in marital infidelity.
Discussion
Its not QUITE that bad - a Frenchman who is certain, willing (and wealthy) enough to go to court to disclaim paternity of a child can get a test ordered:
https://en.m.wikipedia.org/wiki/DNA_paternity_testing#France
The barriers are certainly higher than in other jurisdictions...