NEW YORK — Battle against the Partial-Birth Abortion Ban Act, which began this Monday, is still ongoing as the trials are taking place in 3 cities across the nation; NY, San Francisco and Lincoln,Nebraska.

While opponents of the law say it threatens health of some pregnant women, proponents of the law say it is the way to end pain to the fetus and that partial abortion isn’t necessary to protect women’s health. The law, signed by President Bush on Nov. 5, 2003, applies to the destruction of a fetus after part of it is outside of the mother's body.

In defense of the law, one lawyer said the law is ending an "inhumane and gruesome procedure that causes pain to the fetus."

Assistant U.S. Attorney Sean H. Lane said the procedure, which opponents refer to as partial-birth abortion, "blurs the line between live birth and abortion" and is never necessary to protect a woman's health:

"There are no maternal or fetal medical conditions for which partial birth abortion is necessary for the health of the woman," Lane said. "Second, there are no proven safety advantages to partial birth abortion. Third, partial birth abortion blurs the line between live birth and abortion is an inhumane and gruesome procedure that causes pain to the fetus."

Lane continued, "Doctors and others will testify that it is never necessary to use the partial birth abortion procedure to treat pregnant women. They will say that never encountered an instance where partial birth abortion was necessary. Indeed, they cannot imagine any actual disease or hypothetical combination of medical conditions for which partial birth abortion would be beneficial to the health of the mother."

The government maintains that the ban would affect as few as several thousand abortions annually, while lawyers for plaintiffs say 130,000 of the 1.3 million abortions performed annually in the United States may be affected.

The law is the first substantial limitation on abortion since the Supreme Court's landmark Roe v. Wade (news - web sites) decision. The cases appear likely to reach the high court.

"It is a question of whether Congress can make that determination," said Leslie Gielow Jacobs, a constitutional and gender law professor at the University of the Pacific in Sacramento, California.

"It's the first time Congress has acted in this area, so it's significant," said Jacobs, who is not involved in the litigation. "It has usually been states that have passed bans, not the federal government."