Surrogate mothers.....?

after a surrogate mother gives birth, who pays for the delivery and hospital stay? the actual biological parents because it's their baby, or the surrogate mother because it was technically "her" delivery? justcurious.Surrogate mothers.....?
As long as a surrogate goes through an agency she has legal documents ensuring all of her medical costs during pregnancy will be 100% covered by the biological parents. She can even have her insurance payments covered, her travel expenses covered, etc. When you are a surrogate for a stranger your contract protects you in every way, there should never be a cent out of pocket paid by the surrogate.
The biological parents would unless it states otherwise in the contract. Usually they pay all the medical expenses.Surrogate mothers.....?
I think the biological parents pay for all medical care including hospital/delivery/prenatal care etc.
i think its the biological parents in the US and no1 in the UK (thanks to the NHS)
Usually its the biological parents who pay.