Ryan Murphy may have won the bronze in the men's 100m backstroke but the beaming American had the biggest smile on the night at La Defense Arena on Monday when his wife held up a sign after the medal ceremony to announce they were having a baby girl.

Murphy, a seven-times Olympic medallist, married Bridget Konttinen last year and the 29-year-old swimmer said they will be welcoming a child in January.

"So when I was walking back around, Bridget was holding up a sign and it said, 'Ryan, it's a girl!' So that was Bridget's gender reveal to me," Murphy told reporters.

"That was the first time I heard. Obviously, I knew she was pregnant, but that was the first time I heard the gender. We honestly both thought it was going to be a boy and everyone we were talking to thought it was going to be a boy.

"So that's really, really exciting, that we're going to have a baby and it's going to be a girl. And I think we're only a couple of weeks behind (Jacksonville Jaguars quarterback) Trevor Lawrence too, so that's pretty cool."

Murphy has finished on the podium in the event at the last three Olympics with a gold in Rio and a bronze in Tokyo.

Although a second gold was out of reach having finished behind Italy's Thomas Ceccon and China's Xu Jiayu, the American Rio 2016 champion had no complaints.

"That's a really talented field. I think what I've really improved on over the years is being able to frame things really quickly," Murphy said.

"So immediately when you hit the wall, you're hoping to win and that was obviously my initial emotion - I want to win. But getting third behind Thomas and Xu, they're both really, really talented guys.

"They've been really good at this sport for a long time. They deal well with pressure. So, being third in the world behind them, I'm really not disappointed in that."