Moving to the States & starting a family. Stupid? Career vs family decisions

Hi!

I'm a phd level scientist currently loving my first post doc in the UK. I'm a dual uk & aus citizen and my partner is Irish.

The best thing for my career is to move to the states for ~2 yrs for a second post doc. I'm loving academia & am relatively confident in my ability to secure a job & E3 visa.

The issue is I'll be 32 when we move and we want to start a family. The US is notoriously hostile in its parental leave and we will not have any family support there. This is complicated as I have 2 autoimmune conditions which will need regular, expensive medication so were not keen to delay starting a family.

My partner is in IT and will be reasonably able to find a good job (I hope) attached to my visa, so we should be financially okay. But I'm just wondering if this is smart as academia is notorious in its difficulty & work expectations.

If not, we will just return to Australia but it will be super hard to find a job for me

Could anyone please share their experiences of starting a family in the states with no support? Are there any major pitfalls we're missing? Is it possible to navigate health insurance with pre-existing conditions?