The 27-year-old gold medallist from London 2012 revealed that she and husband Andy are set to be parents this year, having married last May.
This announcement means that Ennis-Hill will miss the 2014 Commonwealth Games in Glasgow, having opted to skip the competition four years ago in Delhi to concentrate on the European Championships and winning bronze in Melbourne in 2006.
In the short term I will make our baby a priority and enjoy the whole experience as much as possible
But she is adamant she will be raring to go for Rio 2016 as she bids to become Olympic champion for the second time.
“I am sorry I won’t be in Glasgow for the Commonwealth Games,” she said.
“But I know it will be an amazing occasion. I will be at home awaiting the arrival of a little Ennis-Hill.
“We are completely overwhelmed, with excitement and a degree of anxiety that I am sure all first time parents will relate to.
“My plans for 2014 have been completely turned upside down, but having had a couple of weeks to think about things from a career point of view I am 100 per cent set on returning to full time athletics once our baby is born and go for a second gold medal at the Rio Olympics in 2016 – that challenge really excites me.
“But in the short term I will make our baby a priority and enjoy the whole experience as much as possible.”