Pregnant Pippa Middleton shows off her blossoming baby bump in Alessandra Rich dress at Prince Louis' christening

Pippa is due to give birth to her first baby in early autumn

Jessica B

Pippa Middleton looked positively blooming as she arrived at St James' Palace on Monday for the christening of her nephew, Prince Louis. The sister of the Duchess of Cambridge, who is due to give birth to her first child with husband James Matthews in early autumn, showed off her growing bump in a pastel blue dress by Alessandra Rich which featured a pleated skirt which she teamed with a matching hat and high heels by Jimmy Choo. She wore her brunette hair up in a chic ponytail and kept her makeup subtle. Pippa's husband James looked dapper in a smart suit and tie. The 34-year-old has clearly developed a special bond with her youngest nephew already. She was the first person to meet the Prince after Kate gave birth to him at the Lindo Wing of St Mary's Hospital in Paddington earlier this year. Given the strong relationship between the sisters, it's safe to assume their children will grow up very closely.

Pippa stunned in a pastel blue dress by Alessandra Rich

It's the second time in recent days that Pippa has revealed her growing bump, having previously kept a low profile for the first part of her pregnancy. On Thursday she showed off her bump as she attended Wimbledon with her brother James. In a relaxed moment, as she was preparing to take her seat in the Royal Box on Centre Court, Pippa was caught side-on – a perfect angle for the cameras. She was pictured holding her clutch with her arms under her stomach, highlighting her protruding bump.

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Monday's christening is a particularly special day as it was the first time the Cambridges have appeared together as a family of five. Duchess Kate looked dreamy in a cream dress by Alexander McQueen as she arrived at the chapel and Princess Charlotte looked super cute in baby blue dress, with older brother Prince George wearing a white blouse and navy shorts.

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The youngest Cambridge is being baptised by the Archbishop of Canterbury, the Most Reverend Justin Welby, who also baptised the Duchess of Sussex earlier this year and lead her wedding ceremony to Prince Harry.

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Mr Welby had earlier said how excited he was to be leading the christening ceremony. He tweeted: "I'm delighted and privileged to be christening Prince Louis today – a precious child made in God's image, just as we all are. Please join me in praying for him and his family on this special day."