Pippa wore a custom dress by Alessandra Rich, and accessorized her elegant ensemble with a matching hat, clutch and heels.
The glowing mum-to-be's husband also matched with a baby blue tie.
Pippa recently opened up about her first trimester in a column for Waitrose Kitchen magazine.
The 34-year-old admitted she did not suffer from morning sickness like her sister Kate.
'I was lucky to pass the 12-week scan without suffering from morning sickness. That meant I was able to carry on as normal,' she wrote.