WHEATON, Ill. (CBS) — A DuPage County judge has found a 27-year-old refugee unfit to parent the child she abandoned at birth but now wants back.

As WBBM Newsradio’s Bob Roberts reports, another hearing that begins Thuirsday in the case of NuNu Sung, of Wheaton, will determine if she retains any parental rights.

Sun is the woman who left her newborn son beneath a clump of bushes, naked, after giving birth in secret in 50-degree temperatures outside of her family’s apartment in June 2009.

LISTEN: WBBM Newsradio’s Bob Roberts reports

The newborn boy was discovered 90 minutes later by a homeowner, suffering from hypothermia.

The second ruling by Judge Robert Anderson, in a hearing that begins at 1:30 p.m. Thursday and could last several weeks, is more crucial, because it will determine if Sung permanently loses parental rights to the boy, whom she calls Joshua and is now 2-1/2 years old. If he stops short, he will outline how and when Sung could regain custody.

The boy’s legal guardian seeks to terminate Sung’s parental rights.

Sung admitted initially lying to police, but decided within hours of his birth that she wanted him back. She required a blood transfusion while hospitalized.

Her attorney, Terra Costa Howard, said that Sung agreed to serve the maximum three-year sentence for obstruction of justice in return for a promise that prosecutors would not oppose her attempt to regain custody.

Sung is imprisoned in downstate Lincoln but is scheduled to be released Jan. 29.