Prince William and Kate Middleton appear to have the perfect family with their three children, but a new report claims the Duchess of Cambridge may be pregnant with her fourth child.

The couple first became parents in 2013 when Kate gave birth to their son Prince George. Two years later, Kate and William welcomed a baby girl named Charlotte. By 2018, the Duchess gave birth to their youngest child Prince Louis.

Due to Kate’s pattern of announcing her pregnancies within two to three years of each other, an expert believes she could be announcing her fourth pregnancy “fairly soon.”

Katharine Graves, who is the author of “The Hypnobirthing Book,” told Express.co.uk that Kate may feel obligated to add another baby to the family.

“Two years between George and Charlotte and three years between Charlotte and Louis. On that basis, we could expect a fourth little Cambridge to be on the way fairly soon,” she said.

“When you live in a goldfish bowl as the royal children do, it must be thoroughly healthy to have siblings to grow up with,” the writer added.

There are a variety of studies that advise women to wait anywhere between 12 to 24 months after giving birth to conceive another child. However, Graves claimed Kate and her sister-in-law, Meghan Markle, appeared to time their pregnancies perfectly.

“All couples think long and hard about how they will space their babies. Nature, of course, has its own ideas on the subject, and pregnancy often doesn’t work out as planned,” she explained.

“In the case of the Duchess of Cambridge and the Duchess of Sussex, their pregnancies seem to have worked out much as planned so far. The Duchess of Sussex was older when she had baby Archie, and the pressure on women over 35 and certainly on women over 40 is enormous to agree to more medical procedures when giving birth.”

Despite pregnancy reports, the palace has not released a statement addressing rumors that suggest Kate is pregnant again.

kate middleton Catherine, Duchess of Cambridge during a visit to the charity Family Action at Peterley Manor Farm on Dec. 4, 2019, in Great Missenden, England. Photo: Chris Jackson/Getty Images