Most couples have a pre-wedding checklist overflowing with tasks to be done before the main event.
That list used to include mandatory blood tests to rule out sexually transmitted disease and German measles.
Because of a recent change in the law, however, that requirement is passe. But other health tests, along with genetic counseling, are increasingly recommended, depending on the couples' lifestyle, risk factors and their plans to start a family.
The law requiring premarital tests for syphilis and rubella (German measles) was repealed last year, partly to reverse the trend of "confidential" marriage licenses, which do not require the blood tests and leave no trace in the public record.
Also, the two diseases do not pose the serious health risks they once did, says Scott Lewis of the state Department of Health Services.
But health officials encourage couples who apply for marriage licenses to consider taking some voluntary tests if they plan to start a family. Those in high-risk groups for contracting the AIDS virus, which can be transmitted from mother to child during childbirth or through breast milk, should undergo an HIV antibody test. And people whose family history or ethnicity increases their odds of passing on a genetic disorder are urged to see a genetic counselor. Details are spelled out in a state-published brochure, "If There Are Children in Your Future," given to couples when they get the license.
While it might seem premature to talk about vows and offspring in the same breath, more and more couples are seeking out genetic counseling before deciding to have children, experts find.
"There's a trend toward preconception counseling," says Bea Leopold, spokeswoman for the National Society of Genetic Counselors, a Pennsylvania-based organization.
"I see an increasing number of people who ask these [genetic] questions before they plan on having kids," agrees Dr. Barbara Crandall, UCLA professor of pediatrics and a genetics specialist. She began noticing the upswing about five years ago, she says.
Although genetic testing is improving all the time, it is far from perfect. Of about 5,000 known genetic disorders, only a fraction, about 300 by Crandall's estimate, can be detected. Couples tend to say, "Test us for everything," but it's not done that way, she explains. In deciding which tests to perform, if any, counselors must weigh the suspicion of risk.
That suspicion is based on a careful assessment done during the initial genetic counseling session. In such a meeting, couples describe any genetic disorders in their medical histories, in their children from previous marriages or in other close relatives, including parents, siblings, aunts, uncles and cousins.
Another important question posed in that session is: "Are the two families related in any way?" First cousins, and possibly second cousins, face an increased risk of genetic defects in their children, Crandall says. That concern diminishes in marriages involving more distant relatives.
Other flags for genetic counselors may include a history of miscarriages or of family members who died very prematurely of causes unexplained by accident or suicide. Counseling is also sometimes recommended for couples whose ethnicity has been linked to certain genetic disorders.
Sickle cell disease, a blood disorder, is most common in African Americans, for example. Tay-Sachs, a condition marked by blindness, deafness and paralysis, occurs more frequently in Jewish people of Ashkenazi descent and in French Canadians.
In some cases, a test may be ordered to determine if a person is a carrier for a genetic disorder. The blood test for cystic fibrosis, a disease marked by chronic lung infections, for instance, detects defects in the gene known as CFTR, says Dr. Bruce Kovacs, USC associate professor of obstetrics and gynecology and a genetics specialist.
"If a woman is found to have one such defective gene, she is a [cystic fibrosis] carrier," he says. If she marries another carrier, their chance of producing a baby with cystic fibrosis is one in four, he says.
For other conditions, however, the assessment is based on empirical information. "The empiric evaluation is like playing bookie," Kovacs tells patients. "You're quoting risk based on what's happened in the past."
Based on an empirical evaluation, for instance, a counselor might tell a woman whose child has one type of cleft lip that her risk of producing another baby with the same defect is low, about 2% to 5%, Kovacs says.