Jessica Alba has "amnesia" about having and raising a baby.

Jessica Alba

Jessica Alba

The 36-year-old actress is pregnant with her third child with her husband Cash Warren, and the star - who already has daughters Haven, five, and Honor, nine, with her spouse - has admitted she has forgotten what it feels like to be woken up by a newborn in the early hours of morning to change their nappies or feed them.

Speaking about the pending arrival and her lost memory to chat show host Jimmy Fallon on 'The Tonight Show Starring Jimmy Fallon', the brunette beauty said: "I have amnesia about having a baby, which is why I think I allowed this to happen.

"I don't remember any of it."

And the Honest Beauty founder has revealed her brood are "stoked" about having another sibling.

When asked about her brood's reaction to the exciting news, the 'Into The Blue' star said: "[They're] stoked."

Although Jessica has yet to reveal the sex of her baby, she has admitted the child will have to a name that begins with the letter 'H' to match their sisters, and their moniker must be "unusual" because her spouse has an odd title, although the name cannot be "too weird".

Speaking about her very specific criteria for her child's name, she said: "So my husband's name is Cash, that's his actual real name, so our kids had to have unusual names.

"That were also H, double syllable, has to be a word, can't be too weird. It has to be a H."

Jessica announced the news she was expanding her brood on social media last month.

The fashion icon posted a cute video of her with her children holding big number one and two balloons, whilst she clasped at the number three inflatable and displayed a visible baby bump.

She captioned her Instagram upload: "@cash_warren and I are officially going to be outnumbered #babyonboard #herewegoagain #blessed (sic)"