The American College of Pediatricians is a small conservative Christian political organization at the margins of the medical professions. They should not be confused with the American Academy of Pediatrics. ACPeds pushes pseudo-science as medical fact. Their positions include opposition to abortion without exception and the notion that homosexuality is curable. They have also stated that gender identity disorder will typically disappear by puberty "if the behavior is not reinforced." Minnesota for Marriage, an anti-gay group supporting Minnesota's marriage amendment, is running print ads touting ACPeds' opposition to marriage equality.
For contrast, The American Academy of Pediatrics is a widely respected medical organization. Their positions and advisories are based on pure science rather than a political or social agenda.
Speaking of Minnesota, according to Wikipedia; Gary Remafedi, a pediatrician at the University of Minnesota,
found his research being cited by ACPeds to argue that schools should
deny support to gay teenagers. Remafedi complained that ACPeds had
fundamentally mischaracterized his work, saying: "It's obvious that they
didn't even read my research. I mean, they spelled my name wrong every
time they cited it." Remafedi complained to ACPeds that his work was
being misrepresented, but the organization refused to correct or retract
its assertions, leading Remafedi to state that ACPeds had "deliberately
distorted my research for malicious purposes."