This is the shift that changes everything.
When an intrusive thought shows up and you respond with what is wrong with me, I must be a terrible parent, this means something awful, normal parents don’t think these things, I hope I don’t have that thought again - that story makes the thought bigger, scarier, and stickier. The thought sets off the alarm, but the story is what keeps the alarm ringing.
When an intrusive thought shows up and you respond with oh, that's an intrusive thought, hello intrusive thought!, my brain is doing its anxious safety-scanning thing, this is a thought not a report card on who I am as a parent - the thought has somewhere to land. And then it can pass through.
And here is maybe the most powerful story of all: I am having this thought because I care so much. Because I love this baby so deeply. My brain is scanning for every possible danger precisely because the stakes feel enormous to me - and they feel enormous because of how much love is here. The thought is not evidence that something is wrong with you, it is evidence of how much you love your baby.
TLDR: The thought itself is not the problem. The story you tell yourself about the thought is what determines whether it stays for thirty seconds or thirty hours.