Prince George and Princess Charlotte's mum looked stunning donning a lacy (telling?) blue Temperley London dress at the Buckingham Palace reception to celebrate those working in the mental health sector on World Mental Health Day (October 10, 2017).
As well as her gorgeous gown, the Duchess of Cambridge's hair and makeup looked perfect, too.
Of course Kate's hair always looks salon-perfect, but there's another reason why the mum-to-be's hair looked extra voluptuous at the event.
Johanne Herald, Senior Master Stylist at Charles Worthington Salons explained just what happens to your locks once you're expecting.
The stylist said: "During pregnancy hair loss (shredding) will slow down making hair look and feel thicker, this is due to the baby taking nutrients and vitamins like calcium and keratin from the hair components."
So depending on your natural hair type, this can be a curse or a blessing.
Just to demonstrate the difference, Johanne defined: "On average women lose around 50-250 hairs a day, regardless if their hair is thick or fine."
She continued: "As well as the daily ‘shred’ every few years women will go through a cycle lasting about three months where they will find hair ‘everywhere’, these cycles occur about 25 times in a lifetime."
So how can fine haired ladies recreate Kate's enviably volume if they're not expecting?
Johanne said: "Kate Middleton's hair is always blow dried to perfection with shine and volume, most likely because she knows she will be photographed! Kate’s hair has always looked extremely thick, most likely due to the products she uses."
She added: "If you suffer from fine hair, try using the Kerastase Densifique range. This helps to boost hair fibres and encourage new growth stimulation, and is different from volumising products which just sit on the cuticle and swells hair for one wash."
From shampoos to intensive masques and conditioning serum, the luxury range has products for every step of your hair care routine if you want to up the amp on your hairstyle. But if you go for one, try the Kérastase Densifique Bain Densité Bodifying Shampoo (£18.50, FeelUnique.com) to gently strip hair of weighty products and add extra va va voom.
Another one to add to our shopping list from Kate's beauty bag for royal beauty fanatics.