For me, pay 50:50. He’s earning and so am i too. Even if you guys are not married, baby is a shared commitment, so he should be paying for it too even if the checkup / blood test and etc are done on you.
I pay for my own check up and scan bills, but my partner always find ways to help cover other expenses such as mom2baby insurance, house installment (only under my name) and daily expenses.
My husband pay for all hospital bills unless the requirement to use my own medisave/medishield/insurance or I have to fork out my own $.
I paid full because me and the baby daddy is not married too.