The singer-and-actress wants to have a big family but fears she may not be able to cope with childbirth more than once.
She told Britain's Star magazine: "I want to adopt before I actually have my own kids. I want three kids - but I don't know if I can give birth three times. I'll have to see how much pain is involved first time round!"
Jessica, who split from husband Nick Lachey in November 2005, insists she has also been inspired to adopt by Angelina Jolie - who has two adopted children, Maddox and Zahara.
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