Mar 13, 2006 -- From The New York Times Metro Section By ANDY NEWMAN It sounds like the setup of a joke: 20 rabbis walk into a fertility clinic. But it really happened. One recent Tuesday afternoon in Brooklyn, a group of young men in yarmulkes packed the waiting room of the Genesis Fertility Center, eyes glued to a roundish smudge on a video screen, absorbing a lecture in basic reproductive technology. "This is the egg," said the center's lab director, sounding like a filmstrip narrator. "Here are zygotes. These are fertilized eggs." From there things got complicated, touching on everything from the shelf life of sperm samples to the mechanics of intracytoplasmic fertilization to the ethics of pre-implantation genetic diagnosis. Arcane as this stuff may sound, the rabbis, all graduate students at Yeshiva University, need to know it, and not just for the course they are taking in infertility and Jewish law. "This is going to be important," said the center's founder, Dr. Richard V. Grazi, as the screen showed a pipette piercing an egg to deliver sperm. "People are going to be asking you a lot of questions about this." As the science of babymaking hurtles into the future, it bumps up more and more against not just the laws of nature but also the laws of God (at least as interpreted by people). Doctrinal riddles on weighty subjects — birth, death, identity and family — that would have seemed like seminary parlor games not long ago are now posed by baffled congregants. "Let's say a woman has a fully functional womb but her eggs are not viable," said Rabbi Kenneth Brander of Yeshiva, the course instructor. "Her sister says, 'Take some of my eggs.' Who's the aunt and who's the mother?" He went on. "What is the relationship between son and father where conception happened posthumously? Does the son say Kaddish for the father?" he asked, referring to the Jewish prayer for the dead. If a couple has six girls and seeks fertility treatment to try for a boy, may they destroy a fertilized egg of the wrong gender? Can a husband in a divorce unilaterally destroy the couple's stockpile of frozen fertilized eggs? "This is not like 'Star Trek' science," said Rabbi Brander, a dean at Yeshiva, which has the largest Orthodox rabbinical seminary in the country. "This is stuff that comes up every day. And if the rabbi doesn't understand reproductive technology he can't answer the questions effectively. If he doesn't know the Jewish law he can't answer them, either." Genesis, on 84th Street in Dyker Heights, retains an Orthodox rabbi — the chaplain at Maimonides Medical Center — to keep things in accordance with Jewish law. Dr. Grazi said that about two-thirds of his patients were Jewish and half of those were Orthodox. Rabbis, of course, are not the only clergy members called upon to square reproductive medicine with religious doctrine. Abdulaziz Sachedina, an expert on Islamic bioethics at the University of Virginia, said he often gets requests from imams and from Muslim doctors to parse some of the trickier issues. Under Islamic law, for example, a couple may use a surrogate mother, but the husband must take the surrogate as a temporary wife. In the United States, Professor Sachedina said, "This is done very quietly." A course in medical ethics is required at many Roman Catholic seminaries. The church disapproves of any pregnancy that does not result directly from sexual intercourse. "It's the difference between something that supplements a marital act and something that substitutes for it," said Msgr. William Smith, who teaches bioethics at St. Joseph's Seminary in Yonkers. After their video lesson, the Yeshiva students descended to the lab and donned scrubs. They toured the incubator room and visited the andrology lab, where sperm is stored in tanks of liquid nitrogen and may be fetched for a kosher couple only under the supervision of a rabbi. "If you want access to the tank," said Rabbi Avraham Friedlander, the Maimonides chaplain, "you need our presence." Offering the students an example of a tension between Jewish law and medical procedure, Rabbi Friedlander explained the circumstances under which a man may produce a sperm sample in the doctor's office. "Usually we ask them to produce at home," Rabbi Friedlander said, "because of modesty concerns. But it has to be brought in within an hour." Afterward the young rabbis pronounced themselves impressed. "Remarkable," said Rabbi Reuven Brand, a fellow in an honors program at the seminary. "The ability of technology to help people is staggering." There will always be some questions that elude easy answers. What if a single woman in her 20's wants to put off motherhood to pursue a career and seeks to freeze some of her eggs for later use? Jews are instructed to multiply fruitfully. Would a rabbi send the wrong message by condoning the postponement of starting a family? And what about the possibility of complications? Now comes the joke. "There are four volumes in the code of Jewish law," Rabbi Brander said. "This is in the fifth volume."