Guidance on how to start a family using a surrogate has been published for England and Wales for the first time by the government.
It recommends written agreements to cover how the baby is conceived and any future relationships between surrogate and child.
The government also advises parents who use surrogates to help their child understand how they were born.
The guidance comes as the numbers using surrogacy are rising.
Surrogacy involves a woman carrying a baby for a couple who are unable to conceive or carry a child naturally. Same-sex couples can also use surrogates in the UK.
In 2016, 368 parental orders were awarded to enable people using surrogacy to become legal parents - up from 194 in 2012.
This reflected the fact that more LGBT couples and people with fertility difficulties were turning to surrogacy, officials said.
The guidance stresses the importance of:
- using endorsed surrogacy organisations to find a surrogate, instead of risky, informal arrangements
- agreeing a written surrogacy agreement to cover everything from conception to expenses, to potential future relationships between surrogate and child
- undertaking surrogacy in licensed clinics in the UK rather than going abroad
Health Minister Jackie Doyle-Price said: "We know that surrogacy can be a complex journey, which is why we have created a guide fit for modern society, one which balances the need for emotional support with clear legal explanations, for surrogates and intended-parents alike."
Sarah Jones, from Surrogacy UK, worked with the Department of Health and Social Care to produce the guidance.
She said: "It is vital that we help surrogates, intended parents and children to have a positive experience and that we support this modern form of family building."
The legislation relating to surrogacy is UK-wide, but there are different approaches to the court systems in Scotland and Northern Ireland. This guidance only applies to England and Wales.
Surrogacy agreements are not legally binding and those involved still need to apply to the family court for a parental order, which transfers legal parenthood from the surrogate to the intended parents.