The 31-year-old, who is pregnant with her first child, dressed her growing baby bump in the same cornflower blue dress that Alexandra wore for Prince Felix's wedding, a gown which is nearly identical to a teal Jenny Packham dress that Kate wore last year.
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Madeleine chose the dress, which is by Japanese-born American designer Tadashi Shoji, for the 2013 New York Green Summit, which she attended with her husband Christopher O'Neill.
The Swedish royal glowed as she arrived at stylish New York venue Apella for the event, which included a royal gala award dinner.
Princess Victoria's sister accessorised her look with a silver, envelope-style clutch bag, large blue earrings and carried a bouquet of white flowers.
On 21 September Alexandra teamed the blue dress with nude patent heels and pearl earrings when she acted as Claire Lademacher's bridesmaid.
The Duchess of Cambridge carried a turquoise clutch bag and sported metallic Jimmy Choos with her bespoke version of Jenny Packham's vintage 'Aspen' dress, when she attended a gala ball for London's 2012 Olympic Games.
Jack Osbourne's wife Lisa has also been seen in the popular blue lace dress.