To think it will be more difficult

[Smilesawyer]

To be pregnant teacher without a TA (year 4)

My mother was pregnant with me in 1984/85 and had 33 in a primary 3 class with no teaching assistant. She managed.

It will be more difficult than if you had a TA, yes.

Yes. It's more difficult to be any kind of teacher without a TA.

I think it's more difficult to be a pregnant Year 1 teacher with several TAs than it is to be a pregnant Year 4 teacher by yourself.

Why do you aks?

Your employer needs to do a new and expectant mother risk assessment, as soon as you tell them you're pregnant. You can then keep them informed of anything that you feel is affecting your or your baby's health. They will need to put reasonable controls into place to ensure both of your health, safety and well-being. If you're not comfortable with any tasks you undertake, discuss it with the Head first, and if no joy, HR or your union. The school should also take HRs advice, plus your health and safety advisor's advice. Good luck, keep well.

Very hard to go to the toilet, I imagine

Be smart, everyone please.

Quite a lot of teachers manage. It'll be fine.
If you need the loo, just ask the next door teacher to keep an ear out for your class while you go.