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...