I am stuck with this sentence in この子誰の子

Hello, I wonder if someone here may be able to help me as I'm terribly stuck with what the following sentence is trying to say. It's just a little too busy for me to wrap my head around it.
でも、カルテを見たって誰に話を聞いたって、君がそれで誕生した子供なのかどうか、わかるはずもない。
I have all the Content words, it's just putting them into a sensible order that I'm failing miserably at.

Any help at all would be amazing.

Thank you in advance,
Regards,
Mosca

The conditional clauses カルテを見たって and 誰に話を聞いたって both explain the impossibility to know it, as in "even if" in English.
君がそれで誕生した子供なのかどうか is an embedded question and the object of わかる.