Catherine, Princess of Wales and her husband, Prince William, returned to their royal duties on Thursday following Catherine’s 41st birthday celebration.

The couple travelled to Liverpool to officially launch the new Royal Liverpool University Hospital, just one day after sending their children back to school.

During their visit, they delighted fans by taking selfies and dressing remarkably similar.

Catherine wore a navy belted dress by Sir Finn and matching Gian Vito Rossi heels, and a tartan blazer from Holland and Cooper to look sophisticated.

However, during her visit to the hospital, Catherine had to temporarily remove two of her most precious jewellery pieces – her engagement ring and her eternity band.

On her fourth finger, she wore her Welsh gold wedding band, but her Anushka Eclipse diamond eternity ring and 12 carat sapphire engagement ring were not present.

According to a local newspaper, the reason for this was to comply with the hospital's policy in minimal jewellery.

The rings are considered a potential hygiene hazard and therefore had to be removed.

She also had to wash her hands thoroughly before touring the wards and treatment areas, so her jewellery had to be removed before entering.

This is not the first time that Catherine has had to remove her jewellery during hospital visits.

In 2020, when she visited the Eve Lina Children's Hospital, she appeared without both bands, choosing instead to solely wear her wedding ring.

Two years earlier, when she spent time with the children at Great Ormond Street Hospital, she did the same.

At the time, Kensington Palace told Hello!

Magazine that Catherine had taken off her accessories because she was visiting the children's ward and, as such, it was important for the Royal to remove any potential hygiene hazards.

Catherine's stunning engagement ring is a sight to behold, consisting of 14 solitaire diamonds surrounding a 12-carat oval blue Ceylon sapphire set in 18-carat white gold.

Her gold wedding band, however, which she usually wears along with her engagement ring, is much more simple.

The Welsh gold wedding ring is an 88-year-old royal tradition dating back to Elizabeth Bower's Lion and the future King George VI.

In 1923, the royal ring was fashioned from a gift of Cugow gold, with enough left over for the wedding of the Queen in 1947, as well as those of the late Princess Margaret, Princess Anne and Princess Diana.

And just before Catherine's royal wedding to Prince William, the Palace announced that her wedding ring would also be made of the Welsh gold.

During her visit to the Liverpool Hospital, Catherine looked elegant in her outfit, completed with her mulberry, amberly handbag and sapphire earrings that nicely complemented her engagement ring, which she had to temporarily take off while she was there.

Catherine took off two of her most precious jewellery pieces for a portion of the royal visit, which lasted many hours.

Catherine's stunning engagement ring often comes off during hospital visits.

This is because the rings are considered a potential hygiene hazard and therefore had to be removed.