OSLO, Norway: Norway's Crown Princess Mette-Marit has had a successful lung transplant and will stay in the hospital for several weeks while she recovers, doctors at Oslo University Hospital said this week.

The 52-year-old wife of Crown Prince Haakon, who is next in line to the Norwegian throne, was diagnosed with pulmonary fibrosis in 2018. This is a long-term illness that causes scarring in the lungs and makes it harder for the body to take in oxygen.

The hospital said the transplant has "so far" been successful, in a statement shared by the palace, but it did not say exactly when the operation took place.

Professor Are Holm from Oslo University Hospital said that, like all patients who receive a transplant, the crown princess will need to stay in the hospital for several weeks. During this time, doctors will adjust her medicines, watch for possible complications, and begin physical rehabilitation.

The surgery comes during a difficult time for the royal family. Earlier this week, Mette-Marit's 29-year-old son from a previous relationship, Marius Borg Hoiby, was found guilty of rape and domestic violence and sentenced to four years in prison. His lawyer said he plans to appeal.

On June 5, the hospital said Mette-Marit had been placed on a waiting list for a lung transplant after her health suddenly worsened, leaving her with about a year to live without the operation.

The crown prince and crown princess thanked the public for their messages of support, the palace said, adding that the next update on her condition will likely come only after she leaves the hospital.

About 30 to 35 lung transplants are carried out in Norway each year, and hospital officials have said that members of the royal family do not get special treatment when it comes to receiving organs.

Although waiting lists are fairly short, strict conditions must be met for a transplant to work, Holm said earlier this month. The donor organ must be the right size and blood type, and doctors must make sure the patient does not have antibodies that would reject the organ.

He explained that success depends on matching the right organ to the right person, which means many factors must come together.

According to hospital data, up to 90 percent of lung transplant patients in Norway survive the first year after surgery, and about 55 percent are still alive after 10 years.

In December, Crown Prince Haakon said the family had noticed a change in Mette-Marit's health and that she was finding it harder to breathe.

Prime Minister Jonas Gahr Stoere praised her for speaking openly about her illness, saying this could help others with similar conditions.

Mette-Marit was 25, a single mother, and not from a royal background when she met Haakon at a music festival in 1999. Their relationship, which initially sparked controversy, later gained strong support from the Norwegian public.

However, support for Norway's monarchy has fallen this year, according to opinion polls, as several scandals have occurred simultaneously.

Hoiby's conviction followed a widely reported trial that dominated the news. At the same time, the crown princess apologized to the king and queen for her past contact with the late U.S. sex offender Jeffrey Epstein, whom she had once called a friend, although she ended the relationship years before his death in 2019.

A Norstat survey in February, conducted during Hoiby's trial, showed support for keeping the monarchy dropping to a record low of 60 percent, before rising slightly to 64 percent in May.