On the eighth day of her son's life, Julia Query welcomed friends and family to celebrate his birth and honor their Jewish heritage.

But there was no crying, no scalpel, no blood, no "mohel" — the person who traditionally performs ritual circumcisions in the Jewish faith. In fact, Elijah Rose's "bris" differed markedly from the ceremony long used to initiate Jewish boys into a covenant with God: There was no circumcision.

"I knew before I was even pregnant that I would not circumcise," said Query, 39, a San Francisco filmmaker whose son was born in 2002. "It's not like you're just cutting a piece of paper off a pad — there's no `cut here' line. It's not made to be cut off, and I would never, ever do that to my baby."

Query is among a growing number of American parents refusing circumcision, in which the foreskin is removed from the penis.

According to a study by the National Health and Social Life Survey, the U.S. circumcision rate peaked at nearly 90 percent in the early 1960s but began dropping in the '70s. By 2004, the most recent year for which government figures are available, about 57 percent of all male newborns delivered in hospitals were circumcised. In some states, the rate is well below 50 percent.

Experts say immigration patterns play the biggest role in the decline, which is steepest in Western states with big populations from Asian and Latin American countries where circumcision is uncommon. The trend has also accompanied a change in Americans' attitudes toward medicine and their bodies.

"The rates of drug-free labor and breast-feeding all rose during the 1980s, while the initial declines in male circumcision rates began during the 1980s as well," said Katharine Barrett, an anthropology lecturer at Stanford University. "It may have been part and parcel of the wider effort to reclaim bodies — adult female and infant male — from unnecessary and potentially harmful medical interventions."

Circumcision remains the U.S.'s most common surgery, and the United States is still one of the few developed countries where a majority of baby boys are circumcised. But circumcision is a heated issue and the subject of vehemently pro and anti Web sites.

"We were all circumcised when I was born," said R. Louis Schultz, a 79-year-old New Yorker and author of "Out in the Open: The Complete Male Pelvis." "People thought it could ward off masturbation or disease, and those funny attitudes have really changed. Now people are saying, `Why do it?"'

Many doctors still recommend circumcision because of some evidence that it reduces the risk of penile cancer, urinary tract infections, HIV and perhaps other sexual transmitted diseases. Many major insurance companies still cover it, and many hospitals offer it free for newborns.

But circumcision opponents say the medical benefits are dubious. Penile cancer, for example, is extremely rare. Since 1999, the American Academy of Pediatrics has not endorsed routine circumcision.

The debate escalated in February, when studies found that heterosexual men in Africa who were circumcised had HIV infection rates up to 60 percent lower than uncircumcised men. Because of those studies, the American Academy of Pediatrics is taking another look at its policy.

About one in three males worldwide is circumcised. In the United States, the rates vary widely by region.

It is most prevalent in the upper Midwest. In 2004, according to data compiled by the federal Agency for Healthcare Research and Quality, more than 79 percent of newborn boys in the Midwest were circumcised before leaving the hospital. Michigan and Kentucky had the highest rates, at 85 percent.

In the fast-growing West, the rate declined dramatically — from 64 percent in 1979 to just under 32 percent in 2004.

In California, the rate of hospital circumcisions among newborns was 21 percent. California — which has more immigrants than any other state — had the lowest circumcision rate in the study, which had comprehensive data on only 27 states.

The decline coincides with rising immigration from Asia and Latin America.

"If you have a solid Victorian, American background, routine circumcision is not unusual," said Carol A. Miller, clinical professor of pediatrics at University of California at San Francisco.

Circumcision was uncommon in 35-year-old Usha Toland's family, which has roots in India, Sri Lanka and Malaysia. When her son, Reynick, was born in 2005 in San Francisco, her husband, Chris, a white man from Southern California, assumed his son would be circumcised. But after the couple read Web sites and medical literature, they decided against the surgery.

"Usha probably would have understood if I really wanted to have Reynick circumcised," said Chris, a 42-year-old advertising executive. "But ultimately I didn't want to bring pain to the child unnecessarily. We wanted to do things the way God or the universe meant them to be."

Many parents fear their boys would feel awkward in the locker room if they were not circumcised.

"I like the idea of him looking like his dad — that's the most important thing for me," said Denise Milito Stockwell, 40, an artist in Chicago who had her 15-month-old son, Harlan, circumcised. "It wasn't traumatic for him in any way. He came back from the event sleeping."

Circumcision is still common in many Jewish and Muslim communities.

Ruth Katz, 38, of San Francisco had both her sons circumcised at brises. She and her husband, Michael Rapaport, were astonished when the teacher in their birthing class described circumcision as "immoral" and "not consensual."

"The edict to have your son circumcised was the first covenant with God — the first challenge to being Jewish," said Katz, pursuing a master's degree in business administration. "I am a progressive person and think a lot about human rights issues, but I have never questioned this."