John Berry is the first to admit he enjoys a beer or two.

But never in his life did he think he'd be mistaken for a pregnant woman, let alone by one of Melbourne's major health services.

The 180-centimetre tall, 90-kilogram man was a little bemused this week when he opened a letter from Sunshine Hospital congratulating him on choosing to have his baby with Western Health.

The letter, addressed to Mr John Berry and containing his individual identification number, urged him to contact the health service if he had any concerns about his impending delivery.

Mr Berry, who originally sought treatment for his hand, said he nearly "hit the floor" when he read the letter. His mates were all now debating whether they should throw a pink or blue-themed baby shower.