In this episode, Katrina and I talked about the fourth trimester in a surrogacy arrangement. Katrina has a formula for how to plan for the fourth trimester, which includes:
the intended parents and surrogate being within a doorway of each other for the first 3-5 days;
the intended parents and surrogate being within 10 minutes of each other for the first 2 weeks; and
the intended parents and surrogate being within a phone call of each other for the first 3 months.
Whilst the distances are figurative (you might not be within a doorway physically, but should expect to be able to knock on each others' doors at any time for those days), the idea is that the parties gradually wean from each other. Intended parents who live interstate from their surrogate, should expect to be nearby for at least the first two weeks.
Katrina also acknowledges that the fourth trimester can be difficult for the intended parents. Like other parents, they are likely to be completely consumed with their new baby, and suffering with sleep deprivation. But on top of that, they also have the responsibility of making sure their surrogate is well and supported, and that she feels loved and appreciated. They can show this with messages and photos (of them with their baby, not just the baby).