Q.I’m going to become a grandmother for the first time, and I was wondering how things have changed since I took care of a newborn many years ago.

Probably the most important change is in the approach to Sudden Infant Death Syndrome (SIDS), the abrupt, unexplained death of an infant younger than a year. SIDS is often called crib death because many victims are found in their cribs.

SIDS is the leading cause of death in children between a month and a year old. Most SIDS deaths occur in children between 2 months and 4 months of age. There are 1,600 SIDS deaths in the United States each year. Unsafe sleeping practices may cause more than 80 percent of deaths.

When we had babies, many of us used to put them on their stomachs to sleep. They seemed to like it and slept well. Now that’s a no-no.

Here’s what you’re supposed to do to prevent SIDS:

• Put babies on their backs to sleep. You can rest them on their stomachs when they are awake and being watched. You should not let babies sleep on their sides because they can roll onto their stomachs.

In 1994, a Safe To Sleep campaign was launched to reduce SIDS deaths from putting babies on their stomachs to sleep. The lead partners in this campaign include the National Institute of Child Health and Human Development, the American Academy of Pediatrics, First Candle/SIDS Alliance and the Association of SIDS and Infant Mortality Programs. Since the campaign started, SIDS deaths have declined by more than 50 percent.

• Babies should sleep on a firm surface such as a crib mattress covered with a fitted sheet. Don’t use crib bumpers; they are unnecessary. No pillows, blankets, stuffed toys in the sleeping area. Put babies in blanket sleepers. Make sure the baby’s head is uncovered.

Sharing your bed with a baby increases a baby’s risk by as much as 40 times. Research does, however, suggest that room sharing is protective against SIDS.

• Research demonstrates that pacifiers reduce a baby’s risk for SIDS. It is believed that pacifiers may discourage babies from turning over onto their stomachs during sleep. Another theory is that the pacifier helps keep the tongue positioned forward, keeping the airways open.

• Make sure babies don’t overheat. The baby’s room should feel comfortable to a lightly clothed adult. Don’t overdress the baby.

• Don’t expose babies to tobacco smoke. Babies whose mothers smoke during pregnancy are three times more likely to die from SIDS. Studies have found that the risk of SIDS increases with each additional smoker in the home.

Researchers have ruled out a number of possible causes of sudden infant death syndrome, including suffocation, vomiting or choking, and infection. There is evidence that many SIDS babies are born with brain deficiencies. Studies of SIDS victims reveal abnormalities in a portion of the brain that controls heart rate, breathing, temperature and the ability to wake from sleep.

SIDS can strike any infant. However, some babies are at higher risk. These include babies who are: male; premature, or born with a low birth weight; anemic; Black, American Indian or Native Alaskan; born in the fall or winter; recovering from an upper respiratory infection; siblings of a SIDS victim; inadequately nurtured; first-borns of teen mothers; and born to mothers with a history of sexually transmitted diseases or urinary tract infections.

Fred Cicetti is a freelance writer who specializes in health. He has been writing professionally since 1963. Before he began freelancing, he was a reporter and columnist for three daily newspapers in New Jersey. If you would like to ask a question, write to fred@healthygeezer.com.