Kate Middleton
Kate MiddletonReuters

Kate Middleton, currently pregnant with her second child, is reportedly following "strict fashion guidelines." The Duchess of Cambridge is said to be wearing dresses with a particular hemline length.

"Being a member of the Royal Family, Middleton needs to abide by the palace's strict fashion style," reports Inquisitr. She is said to be following "style tenants" for her maternity wear. Apparently, the first rule she needs to follow is the "length of hemline." No dress should be above her knee, according to the news site.

"During this royal pregnancy, you'll find the Duchess predominately in dresses, less form-fitting than her norm."

Middleton is also said to be taking fashion tips from personal assistant, Natasha Archer. She is popularly known as Tash.

"Initially Kate was a reluctant fashion icon, but now she enjoys it," a source told Royal Watch. "Tash helps source some of the clothes. She shops a lot for Kate online, and calls in hundreds of dresses for Kate to try on. She has persuaded her to take some more risks," reports Vanity Fair.

Since stepping out in public post her hyperemesis gravidarum (morning sickness), Middleton has been seen in mainly Jenny Packham and Alexander McQueen dresses.

Middleton is in her second trimester. She will give birth to her second royal baby in April next year. Meanwhile, in other news, Middleton and Prince William will be visiting New York. They will be staying at the Carlyle Hotel on Manhattan's Madison Avenue, reports Mirror. They will be in New York from 7-9 December.