Megan, 18, is already mum to son McKenzie, who she stars alongside on the MTV series, and she is due Baby No 2 in April next year.
Confirming she is expecting a girl, Megan has said that plans for the new arrival are already in full swing.
She told MTV: "I'm over the moon to announce I will be having another baby. The bump is due April 1st and...it's a girl! We already have a name picked out and we can't wait to meet her. I'm so excited for Mckenzie to have a little partner in crime."
Megan has also posted a snap on Twitter which shows McKenzie clutching a scan picture of his new baby sister.
Teen Mom UK launched on MTV at the beginning of November and it follows the lives of five teen mothers - Megan, Amber, Chloe, Naomi and Mia.
When Megan fell pregnant, she moved out of the family home and into a caravan with McKenzie's father, Dylan. During the launch show, Dylan proposed...before Megan discovered he had cheated on her with her best friend.
Megan split with Dylan after he dropped this bombshell. It has not been confirmed whether he is the father of her unborn child.
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