Katie Price won't find out the gender of her unborn child.

The former glamour model is pregnant and though she knew the genders of her kids, Harvey, 10, Junior, seven, and five-year-old Princess Tiaamii, before they were born, she has vowed to keep the sex of her fourth offspring a surprise as it is her new husband Kieran Hyler's first baby.

She said: ''I've always known the sex of my kids in advance but this time it will be a surprise as I already have boys and a girl and it's Kieran's first so he doesn't want to know yet.''

The 34-year-old star is suffering from terrible morning sickness and has praised Duchess Catherine - who was known as Kate Middleton before her marriage to Prince William - for continuing with official engagements despite being hospitalised with similar problems early in her pregnancy.

She added in her column for The Sun newspaper: ''I am suffering from morning sickness all day long, so I know how hard it must be for [Catherine] to get all done up, put on a grin and go about those royal duties.

''All mums know that we make arrangements but they often have to be cancelled because when a wave of sickness comes we just want to pull on our tracksuits and curl up on the sofa.

''Kate doesn't have this luxury so let's keep supporting her rather than making a fuss when she seems to get a small thing wrong.''