Hilary Duff Expecting Baby No.#4

Hilary Duff has announced she is expecting her third child with husband Matthew Koma, her fourth child overall.  

Alongside a family photo, showing Hilary cradling her baby bump, she wrote, "Surprise Surprise!"

She is already mother to Luca (11), Banks (5) and Mae (2). She co-parents Luca with ex-husband Mike Comrie. 

The news comes soon after Hilary and Matthew celebrated Banks' birthday. 

"Banks- the sweet/spice/dancing butterfly of our family! 5 years of memories with you are burned on my heart and soul forever and begging for more! You are all the top ingredients! Whimsical, yet practical. Smart-clever-cautious, yet free! Thanks for being ours and for being weird and princessy all in one glorious package!!!"

"Gosh I love you so much! To the best big and little sister there ever was! Happy 5 my little cherry bomb ! I sure hope the next 5 go by a little slower, all the cuddles, tickles, Taylor Swift, brain teasers, treats and trampoline bounces 4life my queen."

Matthew also celebrated the special day with a his own message.

"Being your dad is the greatest gift of my life and seeing every day through your rainbow tinted eyes has colored our family with all the good there is in the world. I'm blown away by your wit, kindness, heart, affinity for Dawes and I can't even imagine what magic will come along with your 5th year on this planet. I love you forever and when we let you have social media at 37, you'll see this post and maybe feel a little guilty for telling me you love mommy more all the time."

A few weeks earlier, Matthew penned a tribute to Hilary for her birthday. 

"It's wild to think this first photo of us was taken almost ten years ago. I remember it so vividly, it's almost like we didn't break up three times between then and now."

"You blow me away everyday with your ability to juggle the un-juggle-able… you do it with such ease & grace. You have an endless well of energy and patience that makes you the super-mom + super-wife you are, all while bringing your wildest dreams to earth level, then still somehow giving a shit about our dogs at the end of the day."

"We're the luckiest, our kids are gonna be so stoked when they find out Ed Sheeran is their real dad. #paidad."