I was told the opposite... That many babies get heart murmurs, but most go away by the time they are 6 months old?!!? I would venture to say that it may be a PDA. All babies are born with PDAs (a tiny hole in the heart that usually closes a few hours after birth), but a lot of premature (even as late as 37 weeks)take longer for that hole to close. Our pedi first heard Ainsley's heart murmur when she was 8 weeks old, and we took her to a pedi cardiologist.
She had the PDA, an ASD (hole between the atriums) and the valve that went to her lungs was sluggish. The really good news is, that at one year, her PDA and sluggish valve had completely healed, and her ASD was almost completely closed.
I completely freaked out about Ainsley's heart, but our pedi cardiologist said that babies with MAJOR heart problems do not gain weight, they work so hard to eat that they break out in a sweat and are usually pretty lethargic. That always kept me from worrying.
Take care, I'm not a doc, just a mom who has been down that road!!
Texas Chapter President
Ainsley Kathryn 11/26/02-36 Weeks Preeclampsia