The blonde royal glammed up for a night out on Wednesday evening, attending the British Olympic Ball at The Dorchester hotel in London.
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Zara dressed her bump for the occasion in a black floor-length gown and accesorised with diamond studs and a mulberry clutch. She had swept her blonde locks up into a chic up'do.
The eventing silver medalist joined fellow Team GB members including newlywed cyclist Victoria Pendleton at the fundraising gala which will give athletes a vital boost ahead of the Sochi 2014 Winter Olympics.
Expectant Zara has currently put her equestrian career on hold, but has said she hopes to get back into training as soon as she can following the birth, with a view to competing in in the World Eventing Championship next August.
She has also revealed plans to take the little one with her on the eventing circuit, just as her mum Princess Anne did when Zara was a baby.
In an interview with Australian Women's Weekly Zara and husband Mike Tindall revealed that they don't know the sex of the new arrival and are eagerly awaiting to find out when he or she arrives in January 2014.
"I'm really looking forward to it," said Mike. "But I'm not sure how I've prepared. We've been pretty relaxed. We've not sorted a nursery yet.