A booklet and DVD can help new mothers understand that newborns may cry a lot, and help them handle their infants' crying, a new study indicates. The hope is that this strategy might prevent cases of shaken-baby syndrome.

Shaken-baby syndrome refers to a brain injury sustained when an infant is shaken violently. Often, such incidents happen when parents become frustrated by their baby's crying.

The new study, published in the journal Pediatrics, looked at whether educational materials could improve new mothers' knowledge of infant crying and the dangers of shaking a baby.

Researchers led by Dr. Ronald G. Barr, of the University of British Columbia in Vancouver, Canada, randomly assigned more than 2,700 mothers to receive either the booklet and DVD on infant crying or a DVD on general infant safety.

The booklet and DVD dealing with crying prepared the mothers for what to expect in the first few months of their newborn's life — including crying that increases weekly, peaking in the second month; unpredictable bouts of crying for no obvious reason; and times when the infant will be "unsoothable."

The materials also stressed the dangers of shaking an infant and suggested ways to comfort a baby, such as carrying, walking and talking. They recommended that when frustration sets in, parents put the baby down in a safe place and walk away to calm down.

Two months after delivery, all of the mothers in the study were interviewed.

In general, the researchers found, mothers who'd received the booklet and DVD were more aware of what constitutes normal infant crying, as well as the dangers of shaking. They were also more likely to have warned family members or other caregivers to never shake the baby.

"These results are encouraging as the first test of these materials to change knowledge and behavior," Barr and his colleagues write. The next step, they say, is to see whether that translates into fewer cases of shaken-baby syndrome.