Prosecutors who charged a mother with murdering her infant because she ate rat poison while pregnant have asked the Indiana judge trying the case to take steps that critics say could stifle any sympathy jurors might have for the woman.

Bei Bei Shuai's story has generated a wave of support from advocates who fear that her case could establish an unequal system that would effectively make pregnant women beholden to stricter rules than others under Indiana law.

Shuai, a 36-year-old Chinese immigrant from Shanghai, was eight months pregnant and heartbroken after a breakup when she ate rat poison in December 2010. She was hospitalized and doctors detected little wrong with the fetus' health for the first few days. Shuai gave birth to Angel Shuai on Dec. 31. Three days later, the baby died from bleeding in the brain. Medical staff reported her to the police; her lawyers said it was a suicide attempt.

Prosecutors charged her in March 2011 with murder and feticide, saying her suicide note proved she intended to kill herself and her unborn baby. Shuai's lawyers say Indiana's fetal murder law was intended to apply only to people who attack pregnant women.

Her trial is scheduled to start April 22.

Prosecutors have asked Judge Sheila Carlisle to bar courtroom spectators from wearing buttons expressing opinions about Shuai and to bar defense attorneys from questioning witnesses about their religious beliefs or from asking questions or presenting testimony that could create sympathy for Shuai.

During Shuai's bond hearing in April 2011, a friend testified that Shuai seemed happy after she gave birth to her child and that she wept as she cradled the dying baby after she was removed from life support. Shuai was treated for depression for months before she her arrest.

Prosecutors say motions such as the one they filed last week are standard.

Shawn Boyne, a professor at the Indiana University School of Law in Indianapolis and an expert on trial procedure, said that while the type of motion is "relatively routine," its scope is unusual. Boyne said she understood the motive behind efforts to block questions that could elicit sympathy.

"In some cases, merely asking a question may plant a question in a juror's mind," she said.

Shuai's attorney, Linda Pence, said she didn't know how she could adhere to such a restriction. "You can't ask a court or ask a lawyer to word their questions to avoid sympathy. That's something the jury determines, not the lawyers."

Boyne said witnesses' religious beliefs could be relevant if they motivated doctors and nurses to report Shuai to police.

As for the spectators, Boyne said the U.S. Constitution and legal precedent protect their free speech rights, provided they're not disruptive.

"Since it is the defendant's right to a fair trial that we are concerned with, I don't understand why the state would be prejudiced by this speech," she said in an email.

A spokeswoman for Marion County Prosecutor Terry Curry said the motion was intended to make sure Shuai is tried based on the evidence.

"We don't want to try this case in the media. We feel the case is best handled in the courtroom on its merits," said Curry's spokeswoman, Peg McLeish.

A petition on change.org urging the state to drop the charges against Shuai has nearly 11,000 signatures.

"This case aims to set a precedent that reduces pregnant women to walking wombs under total state control and surveillance at all times, subject to getting thrown in jail if for whatever reason we can't or don't obey," said Brooke M. Beloso, an assistant professor in gender studies at Butler University in Indianapolis who started the petition.

A group that is helping to defend Shuai said the issue is one of equality.

"I think the motion is an admission by the prosecutor that the case is recognized by a growing number of people in Indiana who recognize he is setting up a separate and unequal system of treatment that is going to affect all pregnant women, not just Bei Bei Shuai," said Lynn Paltrow, executive director of the New York-based National Advocates for Pregnant Women.

McLeish declined to discuss the motivation for the motion.

"The prosecution is simply requesting that the Rules of Evidence be adhered to throughout the proceedings and to clarify those standards and expectations at the outset before any concerns arise. Ultimately, the state wants this and any case to be tried on its merits," she said in a statement.

As concerns the evidence against Shuai, Carlisle ruled in January that the doctor who performed the autopsy on Angel can't testify that rat poison was the cause of her death because she didn't consider other possibilities, including a drug Shuai received in the hospital. Curry hasn't said whether he'll seek another medical opinion.