The 38 year-old actress and her husband Will Kopelman – who already have a 13-month-old daughter Olive – are expecting their second child.
A representative for the couple confirmed the news to a US news website yesterday.
It follows Drew’s red carpet appearance at the LACMA Art and Film Gala on Saturday where her baby bump could be seen under her flowing dress.
The mum-of-one recently told US TV show host Jay Leno that she wanted a baby brother or sister for her daughter ‘very much, right away.’
'I want another baby very much, right away’
'I grew up as an only child, and although that really works for some people and for some parents that's the way they want to do it.’
She added: 'I want to be the Griswolds. I want the kids in the back rolling their eyes at mom and dad. I want Rusty and Audrey, theme parks and the whole nine.'
Drew married Will in June 2012 - three months before the arrival of their first baby. Unlike in her two previous, short marriages to Jeremy Thomas and Tom Green, Drew has settled into family life with Will.
She told a US magazine after Olive’s arrival: 'I really wanted a wonderful traditional home for my kid. Will comes from a strong family, he provides a strong family ... It just makes me so emotional because it's like a miracle.'
The former child star – who found fame with E.T. the Extra-Terrestrial in 1982 – has said she won’t bring up her children in the spotlight.
‘I had such an exposed childhood…I appreciate my journey, but I don't want that for my kid,’ the star once said.
Congratulations Drew!