After months of intense legal wrangling and a major shift in the prosecution's strategy, the case against Mia Sardella will effectively conclude when she is sentenced Jan. 22 - two years to the day after police found her baby boy's decomposing corpse in the trunk of her Volkswagen Beetle.

Sardella, with pale skin and jet-black hair, resembled a porcelain doll as she stood yesterday before Delaware County Judge Patricia Jenkins with a tissue in her hands, sniffling back tears.

The 20-year-old Drexel Hill woman, charged with killing her infant on New Year's Day 2007, pleaded no-contest to involuntary manslaughter, concealing the death of a child and abuse of a corpse.

The manslaughter charge, the most serious of the three, is a felony in Pennsylvania when it involves a child under age 12.

Sardella's son was about a minute old when the then-Drexel University freshman suffocated him after giving birth over a basement toilet, then stashing his body in her trunk, police said.

Three weeks later, Sardella's mother, Stephanie Leone, borrowed her car and opened a pink duffel bag in the trunk. There she found the child, swaddled in bloody clothes with his umbilical cord still attached.

"I saw the arm of a baby," Leone testified at her daughter's preliminary hearing.

Yesterday, Leone clasped her hand over her mouth as Sardella entered her plea by answering in the affirmative to a series of routine questions from her attorney and the judge. Each "yes" seemed less audible than the preceding one.

Involuntary manslaughter, which does not include a mandatory minimum sentence, carries a maximum sentence of five to 10 years' imprisonment when it is a felony, but the standard guidelines call for nine to 14 months in jail. The two other charges are misdemeanors.

The no-contest plea means that Sardella is not contesting the facts that led to the charges, but she is not admitting outright to committing the crime, either. It has the same legal effect as a guilty plea.

Jenkins refused to lift a gag order on the case until after next month's sentencing, prohibiting prosecutors, defense attorneys and relatives from commenting to the news media. Such orders are typically issued in high-profile cases to prevent tainting a jury. Sardella still has the right to take the case to trial by revoking her plea prior to sentencing, but that is an unlikely scenario.

Deputy District Attorney Michael Galantino told the judge that he had enough evidence to convict Sardella if the case went to trial. Defense attorney Arthur Donato said that he intends to submit a memorandum to the judge in which he likely will argue for the lightest possible sentence.

From the start, Sardella's case was as unusual as it was tragic.

Nearly four months after the infant's body was discovered and charges still had not been filed, Upper Darby Police Superintendent Michael Chitwood Sr. accused Delaware County District Attorney G. Michael Green of dragging his feet, partly because of Sardella's family connections. She is the granddaughter of Albert Piscopo, chief executive of the Glenmede Trust Co. investment firm.

"If this would have been somebody from a lower socio-economic background, would we be here today? My experience is we wouldn't be," Chitwood said at a May 2007 news conference he called to air his grievances against Green and county Medical Examiner Dr. Fredric Hellman.

Green's office denied Chitwood's claim as "patently ridiculous," and Hellman released the autopsy report the following week, finding that the infant's death had been caused by asphyxiation. He ruled it a homicide.

Sardella was promptly charged with a long list of offenses, including first-degree murder.

But five months later, prosecutors withdrew first-degree murder, determining that there was "insufficient evidence" to make that charge stick after conducting an "extensive review" of the forensic evidence and consulting with medical experts. They also withdrew the voluntary-manslaughter charge.

Piscopo, who sat stoically yesterday in the back of the courtroom, previously testified that Sardella told him she "wasn't aware she was pregnant" until she went into labor, and that she claimed that the infant was born dead.

"It was shocking to her," he said, "that she was delivering a baby."