Kate Middleton Kate Middleton, Britain's Duchess of Cambridge, at the Botanical Gardens in Christchurch on her Australia-New Zealand tour in April 2014. Photo: Reuters

Kate Middleton showed her face in public last week for the first time since announcing she is expecting her second child with Britain’s Prince William, but that doesn’t mean she will continue participating in her royal duties. The palace announced Thursday that Middleton, the Duchess of Cambridge, had canceled her plans to tour Malta this weekend.

“Her Royal Highness continues to suffer from the effects of hyperemesis gravidarum. The decision not to travel was taken by the Duke and Duchess on the advice of the Duchess’s doctors,” the palace said in a statement. Middleton’s husband, Prince William, will take her place. “The Duke is honored to represent Her Majesty the Queen on the visit,” said the palace. “The visit itinerary remains unchanged.”

The palace confirmed earlier this month that Middleton, 32, was pregnant with her second child and suffering from an acute form of morning sickness. The Duchess has already canceled one appearance due to the pregnancy illness. She first suffered from the sickness during her pregnancy with Prince George, now 13 months, in 2012.

The palace first announced in July that Middleton would be visiting Malta on behalf of Queen Elizabeth II in celebration of the republic's 50 years of independence. The trip would have been Middleton’s first solo tour. She last visited Australia and New Zealand with Prince William and Prince George in April.

Despite her trip cancellation, and her rumored desire to remain absent from the public eye during her pregnancy, Middleton was recently photographed out and about sporting a small baby bump. Radar Online reports that the Duke and Duchess of Cambridge were seen leaving King's Head pub in Great Bircham near their Anmer Hall home in Norfolk on Sept. 11. "Locals were stunned to see the royal couple saunter in and sit at a quiet table in the corner,” said a source. “Towards the end of the meal, a couple of stunned locals introduced themselves to the royal couple and shook their hands."

Middleton is reportedly less than 12 weeks along in her pregnancy. She is rumored to be due in March or April 2015.