I see a future where you’ll need a contract to have a child and it will include support for 21 years between both DNA donors. Most people will lack the financial availability and would not qualify for parenthood. Illegal pregnancies would result in 21 years minimal prison sentence for both DNA donors.
With that, two person contracts will replace the religious concept of marriage. It will require an equal support for both partners financially. The contract would allow separation for domestic violence or failure to produce a human child. No Divorce would be authorized under any other circumstances. No new contracts would be authorized for a new partner if a DNA donor child is under the age of 21.
So yes, if you enter into a contract to produce a child, your stuck with that choice for 21 years.