Kate Middleton
Kate Middleton doesn't give birth to a public hospital for a reason. Pictured: Middleton takes part in preparations for a Commonwealth Big Lunch at St Luke's Community Centre on March 22, 2018 in London. Getty Images/Paul Edwards

There's a reason why Kate Middleton prefers to give birth at a private facility than a public one.

Some royal fans might be wondering why the royals, including Middleton, prefer to get private maternity treatment. St. Mary's Hospital is an NHS-owned healthcare center. However, the Lindo Wing, where the Duchess of Cambridge is set to deliver her third child, offers private healthcare. Middleton delivered Prince George and Princess Charlotte in the same facility in 2013 and 2015, respectively.

"There's a lot of noise about them wanting to be ordinary and wanting to give their children ordinary upbringings, but yet so many things about their daily lives are not ordinary," royal correspondent Victoria Murphy explained.

"With private hospitals it's probably a bit easier for them to have a more controlled environment without disrupting larger services," Murphy continued. "That's the kind of thing they're always trying to do in terms of security and in terms of privacy."

Murphy believes that royals giving birth at an NHS hospital will be more difficult for the other patients and staff. She added that expecting the members of the royal family to deliver at a public facility would be "unrealistic."

An insider revealed earlier that Middleton will give birth in a luxury maternity ward that costs $9,650 a day. The room is ready and has been lockdown since March. In addition, security is tight.

"Security does regular sweeps of the room, then it's resealed each time with tamper-proof tape. It's a high-security operation. Even the crawl space above the room is checked regularly," the insider said. "Everything is planned down to the tiniest detail."

On the other hand, St. Mary's Hospital has been preparing for the Duchess of Cambridge's delivery too. A few weeks ago they repainted the railings outside the Lindo Wing. Earlier this week, they put a "No Parking" sign in the area. They also did these when Middleton delivered Prince George and Princess Charlotte.

In related news, Prince William was spotted watching Aston Villa's game on Tuesday. The Duke left his heavily pregnant wife at home to enjoy his favorite team's football match.

While many were happy to see Prince William, some were not pleased with his choice. Middleton is expected to deliver any time now.

"His missus is heavily pregnant and Prince William is off gallivanting at the Aston Villa match," one critic wrote.