This will be the "Zoey 101" alum's first child with voice actor husband Jamie Watson.
Spears, 26, took to Instagram to break the news to her fans and followers.
"Looks like we are starting off 2018 with another big milestone... So happy to announce that Maddie is finally going to be a big sister 2017 was filled with some of the biggest challenges of my life, as well as some of the biggest blessings, so I made a choice to lay low this year to focus on truly becoming my best self as a person and as an artiste," she wrote in the post.
She shares Maddie with her former fiance Casey Aldridge.
Her elder sister, Britney Spears, also took to the social media to congratulate her.
"Maddie is going to be the best big sister! So happy for you @jamielynnspears! Love you all so much!" she wrote.
Disclaimer: No Business Standard Journalist was involved in creation of this content