Defendant is charged with sexual assault of a child. Years ago, as a juvenile, defendant was adjudicated and sentenced to an indeterminate sentence for indecency with a child.

I don't see anything in 38.37 that would prohibit me from admitting this juvenile adjudication but I'm unsure if there is some other provision that I'm unaware of that would bar admission of the adjudication at trial.

Any help is appreciated.

It would depend on what you use it for. Look at Family Code § 51.13. That section explains the limitations on using adjudications and dispositions of juvenile offenses.