Parents who sleep alongside their baby in bed or on the sofa could be putting the newborn at risk of sudden infant death syndrome (SIDS), the health advisory body has warned.

But the National Institute for Health and Care Excellence (Nice) stopped short of telling parents to stop the practice, admitting that health professionals are "stuck between a rock and a hard place" because of conflicts over breastfeeding.

Instead, updated guidance published today intends only to make parents aware of an association between co-sleeping with their baby in a bed, on a sofa or on a chair - even occasionally - and an increased risk of SIDS up to the age of one year.

The link is greater when a parent, including a partner, smokes, drinks alcohol or take drugs prior to co-sleeping or if the baby was born prematurely or with a low birthweight.

More than 200 babies in England and Wales die unexpectedly in their sleep every year for no apparent reason, most commonly between the ages of four weeks and 12 weeks.

Professor Mark Baker, Nice's clinical practice director, said he understood the new guidance could be confusing but believed it was better for parents to make individual decisions about co-sleeping.

"We're not telling people not to co-sleep with their babies, we know that could get in the way with breastfeeding, but there is an association with SIDS and it's better that parents should know and make their own judgments," he said.

"It's quite a confusing message, it is not clear.

"We are between a rock and hard place. The only recommendation we could have made would be to avoid co-sleeping but it would be seen as incompatible with breastfeeding guidelines.

"We've got good guidance about breastfeeding but there are these statistics indicating an association with SIDS that parents should be aware of."

Elaine McInnes, a professional development officer from the Institute of Health Visiting who helped to develop the new Nice co-sleeping recommendations, said health professionals should discuss safe sleeping arrangements with parents before the baby is born.

"Being a new parent is exhausting. We know that many new mothers and fathers will, at some point or another, fall asleep with their newborn and parents should not feel guilty or embarrassed," she said.

"Sharing a bed with your baby at night can aid breastfeeding and in some cultures, co-sleeping is seen as perfectly normal.

"However, the Department of Health advises that the safest place for a baby to sleep is in a cot, and if that cot is beside the bed, it need not interfere with breastfeeding.

"The conversation about co-sleeping and the factors that may make SIDS more likely should begin before the baby is even born and discussed at every visit, up until the child reaches its first birthday."

The Department of Health continues to advise that the safest way for a baby to sleep is on its back, in its own cot or Moses basket in the parents' room for the first six months.