Kate Middleton's severe morning sickness has prevented her from attending another major event.

Kate Middleton & Son Head To Her Hometown To 'Relax'

The 32-year-old reportedly hoped and planned to attend an event as part of her sailing charity, 1851 Trust, in Portsmouth on Monday but couldn't make it because of her illness.

The Duchess of Cambridge started the charity in June along with Olympic gold medalist Sir Ben Ainslie in order to encourage those 25 years old and under to get involved in sailing and have the chance to win the America's Cup. A British team has never won the America's Cup, which was first held in 1851 in England.

Learn 7 Interesting Facts About Prince George 

"I am delighted to be Royal Patron of The 1851 Trust. I feel very fortunate to have enjoyed sailing from a young age and I know it is a great way of providing young people with the opportunity to develop skills and confidence," she said in a statement.

"It is a hugely exciting time for sailing as the British challenger bids to bring the America's Cup back to Britain. I am looking forward to being part of this journey and I hope that through the 1851 Trust we can engage and inspire a new generation into sailing along the way."

Prince William's wife has been forced to cancel several appearances after it was announced in September that the royal couple was expecting their second child. For example, Middleton wasn't able to attend launch of The Clore Art Room at Barlby Primary School in London on Oct. 1 as well as a trip to Malta. It's also unclear if she will be able to visit the president of the Republic of Singapore later this month as expected.

Middleton suffered from the same condition during her first pregnancy with Prince George; however, she's "being treated by doctors at Kensington Palace," a royal announcement revealed last month.