One of the nation's few late-term abortion doctors was ordered Wednesday to turn over about 2,000 patient medical records to a Kansas grand jury investigating his practice.

Abortion opponents hope that the records will lead to further criminal charges against Dr. George Tiller, who already is facing 19 misdemeanor counts stemming from late-second and third-trimester abortions at his clinic in Wichita.

Tiller's lawyers say he scrupulously follows the law. They plan to ask the Kansas Supreme Court to overturn a state district court judge's ruling that Tiller begin handing over files as early as today.

"It's an unprecedented encroachment upon a woman's right to privacy," attorney Dan Monnat said.

Monnat was joined in court by a lawyer from the New York-based Center for Reproductive Rights, who filed affidavits from three patients demanding that their medical records remain private.

Even though the judge ordered names and addresses removed from the files, the patients said they feared their identities could be deduced from details about their families and medical histories. The antiabortion group Operation Rescue has given the grand jury several photos that it says show pregnant women entering Tiller's clinic; the same pictures are posted online, with the women's faces blurred.

"Even thinking about the possibility of anti-choice extremists identifying me has caused my partner and I great distress," one woman wrote.

The unfolding legal dispute treads familiar ground.

Tiller spent three years battling a subpoena for a much smaller group of medical records sought by former Atty. Gen. Phill Kline, an opponent of legal abortion. The Kansas Supreme Court eventually forced Tiller to turn over 60 records on the condition that an independent lawyer first review them to redact names, addresses and other information not relevant to the criminal inquiry.

After Kline was voted out of office, his successor -- a supporter of abortion rights -- charged Tiller with the misdemeanors.

In that case, which has not yet gone to trial, Tiller is accused of aborting viable fetuses without consulting an independent physician as required by state law. He did consult a second doctor, but the prosecution alleges that she was not truly independent because all her income came from her occasional work with Tiller.

The grand jury investigating possible additional charges against Tiller is demanding the medical records of every patient who sought or obtained an abortion after her 21st week of pregnancy, or midway through the second trimester. The panel wants records dating back to July 1, 2003.

The grand jury also has subpoenaed the names and addresses of Tiller's employees and of physicians who have worked with him.

Monnat called such demands an attempt to intimidate Tiller, who has weathered decades of protests and violence directed at him by antiabortion activists

"Dr. Tiller has been bombed and shot at, and those incidents have not prevented him from providing high-quality healthcare for women who so desperately need it," Monnat said. "This additional attack will not blackmail him."

Tiller has reported aborting more than 2,600 viable fetuses in the last decade at his clinic, Women's Health Care Services, which draws patients from across the country.

Under Kansas law, aborting a viable fetus is legal only if two doctors certify that continuing the pregnancy could kill the woman or cause "substantial and irreversible impairment of a major bodily function." The Supreme Court has repeatedly made clear that the woman's mental as well as physical health must be taken into account.

Tiller has said his late-term patients -- some well into their third trimester -- include girls as young as 10, drug addicts and victims of domestic violence. He specializes in abortions for fetal anomalies; those patients tend to be women who very much want a baby but learn late in pregnancy that their fetus suffers from a serious genetic disorder.

According to court records, Tiller has approved abortions for some patients after diagnosing them with anxiety or an episode of "major depressive disorder." Abortion foes contend that these are not valid reasons for late-term abortions under Kansas law, because they don't equate to "substantial and irreversible impairment" of the woman's health.

"I think the grand jury should run in and grab those medical records," said Troy Newman, president of Operation Rescue. "This is the frontline for abortion in America."

stephanie.simon@latimes.com