Today the 40-year-old BBC journalist revealed that she and husband Michael Heron are expecting a baby in October.
She conceived the child naturally after four failed IVF attempts over a number of years.
Kate told fans in a series of posts on the social networking site after explaining that she was no longer able to get a puppy – something the couple had been considering recently.
She posted: 'Now a little announcement I have to make - for those of you who have asked about the puppy there is sad news... We cannot get it...
Adding: 'Because we had some very unexpected - but lovely news just recently.....'
'I am pregnant'
Kate, who married Michael in December last year, said she had decided to make the announcement after 'a shaky three months' but said she is 'absolutely thrilled.'
The journalist has fallen pregnant after she had given up hope of having children after two years of trying with her now husband. In 1999 she had an emergency operation to remove one ovary after an ovarian cyst burst, while she was reporting from the Labour party conference.
After she had broken the news to her fans, Kate tweeted: 'Ooh that felt odd to announce! We gave up hope of having a biological family last year so this feels something of a minor miracle...'
Kate's news comes just three months after fellow BBC presenter Julia Bradbury, also 40, announced her own miracle pregnancy.