Carrie Underwood has given birth to a baby boy.

The 35-year-old country singer - who already has a three-year-old son called Isaiah with husband Mike Fisher - has revealed via social media that her baby son, Jacob Bryan Fisher, was born on Monday (21.01.19).

Alongside a photograph of herself and her new baby, Carrie wrote on Twitter: ''Jacob Bryan Fisher entered the world in the wee hours of the morning on Monday...his mom, dad and big brother couldn't be happier for God to trust them with taking care of this little miracle! Our hearts are full, our eyes are tired and our lives are forever changed. Life is good (sic)''

Carrie also shared some behind-the-scenes shots of baby Jacob with Mike and Isaiah.

Meanwhile, Carrie previously admitted her pregnancy was ''great news'' following three earlier miscarriages.

She shared: ''It took us a while to get here ... I'm gonna cry again. [I'm] just so thankful to find out Isaiah's gonna have a baby brother. It was just great news.

''We're excited ... Balance is what it's all about, no matter what your job is. Being a mom, working and dividing your time. It's what we all have to do as mothers.''

Carrie endured three miscarriages during a two-year time period, and the singer admitted she was left feeling ''angry'' by the ordeal.

She explained: ''I had always been afraid to be angry. Because we are so blessed. And my son, Isaiah, is the sweetest thing. And he's the best thing in the world. And I'm like, 'If we can never have any other kids, that's okay, because he's amazing.' And I have this amazing life. Like, really, what can I complain about? I can't.

''I have an incredible husband, incredible friends, an incredible job, an incredible kid. Can I be mad? No. [But after the miscarriages,] I got mad. [I thought], 'Why on Earth do I keep getting pregnant if I can't have a kid?' Like, what is this? Shut the door. Like, do something. Either shut the door or let me have a kid.''