The brit milah — Hebrew for covenant of circumcision — is at least as old as the book of Genesis. It's there, in 17:12, that God tells Abraham, "he that is eight days old shall be circumcised among you, every man child in your generations…"

And when it comes to the ceremony of the brit, the old traditions are still uppermost on contemporary parents' minds, according to both Reform and Orthodox mohelim , or ritual circumcisers.

Chanan Feld, an Oakland-based Orthodox mohel who performs an average of one brit a day, sees a trend in brit milah emerging: Parents are turning more toward having a traditional brit, or bris in Yiddish, in the home, because, he noted, "people tend to be looking for more ritual in their lives."

That coincides with the experience of two Reform — and distinctly non-traditional mohelim — Drs. Joel and Jing Hseih Piser. The Pisers, who live in Piedmont, are finding that more parents are requesting that the ceremony be performed in the home rather than in a hospital or doctor's office.

Also, observed Jing Piser, parents are taking a more hands-on approach to the selection of the mohel.

"They're doing a lot more research into the bris," she said. "Frequently the couple will call to interview us several months before the baby is born. The questions they ask indicate they're interviewing all the mohelim in the Bay Area."

Jing Piser, a Taiwanese-born plastic surgeon who converted to Judaism, knows she has a particular appeal to some California Jews, those whom she identifies as taking a "more egalitarian approach" to the brit milah. "More often than not the moms nowadays are the ones doing the initial interviews," she said. "They like me because I'm female, too."

While Jing Piser is pushing the envelope of what it means to be a mohel, both Pisers have encountered some people who are pushing the envelope of what it means to be a Jewish nuclear family.

"A lesbian couple, one of whom was Jewish, and the other one was gentile, came in with their baby son," Joel Piser recalled. "The non-Jewish woman had been artificially inseminated by a Jewish male, and both women wanted the boy to be raised Jewish and have a bris."

Both doctors stressed that the brit milah doesn't make the baby any more Jewish than not having it done makes the baby any less Jewish. "It's just the baby's first Jewish event," said Joel.

In keeping with tradition, both Pisers strictly adhere to the rule that the brit must be performed on the baby's eighth day of life. (Exceptions may be authorized for medical reasons.)

"We recognize that Orthodox Jews are restricted from traveling on the Sabbath, and sometimes that poses a problem for family members who want to be there," Jing Piser acknowledged. "But we impress upon moms and dads that the bris is a covenant, not a ceremony of convenience."

Nevertheless, Orthodox mohel Feld noted that many britot he performs are for Jewish males of various ages, who never had the opportunity to get it done when they were eight days old. The majority of adult circumcisions he performs are for Russian Jewish emigres, who were prohibited from becoming circumcised in the Soviet Union. "The oldest person I've done was around 65," he said, adding that he knew of one man who was circumcised at age 80.

As an Orthodox mohel, Feld said he views the brit "in the context of laws and obligations," but he also said the feelings of families he sees "run the full gamut, from people approaching it with joy, to those who come to it with a great deal of anguish."

He further acknowledged that "there isn't a mother who doesn't have at least some anxiety — it is a kind of surgery — but when it comes to the moment, the parents allow themselves to appreciate the beauty of the ceremony."

Similarly, the doctors Piser also see the brit primarily as a religious ritual, and secondarily as surgery.

"Yes, we are physicians, but in this capacity, we're performing more as religious functionaries," Jing Piser said. "That comes up sometimes when people ask if the bris is covered by medical insurance. We tell them they should think of the bris as a mitzvah, and not merely a medical procedure."

But, Joel Piser added, "that's our own personal approach. Some mohelim do let the families put the bris on their insurance."

Still, for some people, the medical questions persist. But they are answered emphatically by Dr. Mark M. Rubenstein, a mohel and pediatrician who practices in Concord and Antioch. Regarding the ceremonial aspect of the brit, Rubenstein called it "one of the most rewarding things I do." But he's no less passionate about defending the procedure on medical grounds.

"There are all kinds of cogent medical reasons for doing the circumcision," he affirmed. "It's only in uncircumcised boys that urinary tract infections occur during the first year. Also, at the age of 4 or 5, balanitis can develop, which is an infection in the foreskin where it attaches to the head of the penis. And every one of the 5,000 cases of cancer of the penis that occur every year occur only in cases in which the man is uncircumcised."

Rubenstein, one of some 150 mohelim trained and certified by Reform Judaism's National Organization of American Mohelim/ot, calls the brit "a wonderful educational opportunity" for the interfaith couples he sees. Approximately 75 percent of the families for whom he performs a brit are in that category.

"Usually the non-Jewish family members look on with fear, but by the time the ceremony is finished, they feel a sense of cohesiveness within the family," Rubenstein said. "At that time, they will admit that they didn't want to participate, but once they did, they found the bris beautiful."