Billie Piper has given birth to her second son.

The 29-year-old actress and husband Laurence Fox ''couldn't be happier'' after welcoming their second child into the world on Thursday (05.04.12), and the actor has taken to twitter to reveal everything is ''fine''.

He tweeted: ''One born every minute. We had our minute today. Couldn't be happier. Beautiful boy. Everything fine.''

The couple - who also have three-year-old son Winston - are yet to reveal a name for their latest addition to the family.

Following the birth, the former 'Doctor Who' beauty's sister Ellie also tweeted her congratulations to the pair.

She wrote: ''Would like to say welcome new licckel baby boy I love you so much already can't wait so kiss those big lips :) x (sic)''

In November, Billie offered to withdraw from her theatre role in Neil LaBute's London play 'Reasons To Be Pretty' after discovering she was expecting, but director Michael Attenborough was so keen for the blonde beauty to remain in the production that he re-wrote The Script to include her pregnancy.

He explained: ''Billie was Neil LaBute's and my first choice for the part - and fortunately the character is pregnant - so with a bit of judicious re-writing we're all delighted she'll be with us.

''I told her that I'd love her to do it and she just wept on my shoulder. She thought that was it. She was thrilled.''