Modern medicine is amazing -- and the reason Celine Dion is so happy these days.

The singer's doctor, Dr. Zev Rosenwaks, tells People.com that the 41-year-old songstress is pregnant due to in vitro fertilization of an embryo that was frozen eight years ago!

Celine had her embryos frozen back in 2001, when she was trying to conceive her first child. René-Charles was born later that year, and when Celine finished her Las Vegas run in 2007, she was ready for baby No. 2. 

"She came back to have the embryos transferred back because she wanted to have another baby," the doc said.

Should Celine be concerned that it's been so long? 

According to the fertility specialist, no. 

"There have been embryos that have been [frozen] for more than 10 years, and even more than 15 years, that have successfully thawed and resulted in a pregnancy," the doc said.

Which is wonderful news for Celine and her family, who are just giddy over the pregnancy.

"You could hear her chuckling," the doc said, when he told Celine her results were positive. "She was very happy. So was René. They are both very thankful."

Amazing -- and awesome.