A 4½-year-old South Wales girl born with multiple birth defects and health problems has been kept alive by Viagra — as she awaits life-saving surgery.

Cerys Small of Newport was put on the erectile dysfunction drug to help blood circulate around her body, Caters News reports.

She was born in January 2011 with a hole in her heart, no spleen and problems with her digestive system. She was given just a 50 percent chance of surviving to adulthood.

So far, she has undergone five operations in her short life.

“That Viagra kept her alive for more than four years and now she is well enough to keep going until her next operation,” said her mom, Kerrie Small. “People mostly giggle when they find out what medication she was on. We just laughed, too, when doctors told us — it was a bit of a shock.”

In June, Cerys underwent a five-hour operation that had to be aborted because she became a stroke risk. The surgery is now scheduled for early next year.

“Cerys is starting to realize she has got limitations,” her mom said. “She has a wheelchair and can’t walk that far. She’s started to notice people staring at her, but I say, ‘It’s OK, just smile and wave at them.’”