PARIS (AP) — Princess Charlene of Monaco, who married Prince Albert II in 2011, has announced she is pregnant with the pair's first baby.

The 36-year-old South African former Olympic swimmer and her husband issued a statement expressing their "immense joy" at the news.

The short statement says that the birth is expected before the end of the year, which means the princess is at least three months pregnant.

It does not elaborate further.