Jessica Ennis-Hill pregnant

While Ennis has set the Rio de Janeiro Games in 2016 as her goal, fellow heptathlete Louise Hazel believes there must be some doubt over the Yorkshire athlete staying in the multi-discipline event.

Hazel said: "Is it possible to be an elite sportswoman and have a baby? Yes. Is it possible to come back from Olympic gold as a heptathlete and go on to Rio... it throws a huge question over the continuation of a career as a heptathlete and that's just being realistic.

"I think she'll be able to come back and compete. The question is: in what event?

"Will she be able to get back to the same form she's been showing in recent years and be competitive?

"You have to look at people like Katarina Johnson-Thompson, who's been breaking Jess' junior records non-stop."

Hazel, who retired from heptathlon but is planning to continue her athletics career in other events, is backing 21-year-old athlete Johnson-Thompson to claim the Commonwealth title.

The 27-year-old from Sheffield, who married long-time partner Andy Hill in Derbyshire last May, is expecting her first child.

She said in a statement: "I have some very unexpected but exciting news to share - Andy and I are expecting a baby.

"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.

"But in the short term I will make our baby a priority and enjoy the whole experience as much as possible.

"I am sorry I won't be in Glasgow for the Commonwealth Games, but know it willbe an amazing occasion. I will be at home awaiting the arrival of a little Ennis-Hill."

2012 Olympic gold medallist Jessica Ennis-Hill will miss the 2014 Commonwealth Games in Glasgow after announcing that she is expecting her first child with husband Andy Hill.