Watch Live:
News Conference on Missing University of Virginia Student

Kate Middleton, Prince William Attend Friend's Wedding

Kate Middleton isn't letting being pregnant with the royal heir slow her down.

The 31-year-old wife of Britain's Prince William traveled to Switzerland with her husband and brother-in-law, Prince Harry, to attend the weekend wedding of a close friend of both princes, polo player Mark Tomlinson.

RELATED: The Royal Bump Blog, Day-by-Day

William, 30, served as an usher in the wedding between Tomlinson and Laura Bechtolsheimer, an Olympic equestrian, in the town of Arosa. The prince stood out in a traditional tailcoat but it was Middleton's style, as usual, that stole the show.

RELATED: Kate Middleton's Pregnant Fashion Frenzy

The Duchess of Cambridge wore a pale coat lined with a brown fur trim over a MaxMara dress, according to People magazine. She wore a dress by the same designer last month in of her few public appearances since being hospitalized in December, early in her pregnancy.

"She is aware that whatever she wears sells out immediately so we will continue to see her dress in the way she always has done, which is conservatively but elegantly," Victoria Arbiter, royal contributor for ABC News, said of Middleton's style.

Middleton kept her head warm in a James Lock pillbox hat but it was her feet that had everyone talking. The duchess stepped out in decidedly non-maternity shoes, wearing five-inch Emmy heels. Prince Harry helped the expectant mother into the ceremony as William performed his usher duties, People reports.

READ MORE: Is This the Face of the Future Child of Prince William and Kate Middleton?

The royal trio, who were spotted throwing confetti at the newlyweds, turned the wedding at the ski resort into a mini-vacation.

Middleton was spotted carrying a sled while William and Harry hit the slopes, but royal watchers say the duchess is not putting the soon-to-be-born royal heir in any danger.

"She was not seen sledding and I highly doubt she was actually sledding," said Arbiter. "I think really she was just mucking in with everybody else and hanging out."

Middleton is said to be due in July.

More ABC News