It is more critical than which baby foods to buy and more urgent than which school to choose. Few issues provoke fiercer debate among new parents than whether babies should be given a dummy to stop them crying.

Health professionals also disagree. Some back their use for fractious infants - to protect parents' sanity - others reject them for developmental, hygienic or aesthetic reasons. Now, an authoritative study in a medical journal has examined the evidence and concluded dummies are bad for babies and parents should be advised against them.

The review of research published yesterday in Nursing Standard analysed the results of 20 studies conducted around the world over the past decade. It found babies who used dummies were less likely to breast-feed or were breast- fed for a shorter period.

This was partly outweighed by the finding that babies who used a dummy were less likely to suffer a cot death - sudden infant death syndrome (Sids). However, the authors from the Joanna Briggs Institute in Australia concluded: "As breast-feeding confers an important advantage on all children and the incidence of Sids is very low, it is recommended that health professionals generally advise parents against pacifier use."

The researchers found that use of a dummy may reduce a baby's desire to suck, which is necessary to stimulate the supply of milk, leading to diminishing interest in the breast. By contrast, a bottle provides a ready supply of milk from the first suck.

There is widespread concern that dummies damage babies' teeth or increase infection, but the researchers found none of the studies were of sufficient quality to reach firm conclusions on these risks.

A straw poll in The Independent's offices yesterday found parents divided. Supporters of dummies said they prevented thumb-sucking, which continues for longer and poses a greater risk to developing teeth. Nearly half of thumb-suckers still have the habit at the age of nine when their adult teeth are coming through. Opponents said dummies were unnecessary, ugly and could pose problems later on.

A spokeswoman for the British Dental Association said: "Beyond the age of six when second teeth start to come through, thumb-sucking can displace teeth. It may be better for children to suck a dummy because they give it up earlier."

Penny Gibson, consultant community paediatrician in Guildford, Surrey, and spokesperson for the Royal College of Paediatrics, said she knew of no evidence that use of a dummy reduced thumb-sucking.

"Personally, I would not favour giving a dummy at any age. I did offer my first child a dummy when he was screaming but thankfully he spat it out."

She said anything that reduced the chances of breast-feeding was bad for babies. "To stimulate and maintain breast-feeding you need a certain amount of sucking. It is completely different from a bottle when you get a lot of milk very easily."

There were also hygienic reasons for avoiding dummies, she added. "You see a dummy dropped on the floor picked up and sucked clean by the parents - or not, which is probably worse - and popped back in the baby's mouth."

William Yule, professor of applied child psychology at the Institute of Psychiatry, said: "If parents come to me and say their child is being fractious a lot of the time, I'd recommend using a dummy. It won't harm the child, and it's certainly worth a try. Most babies either take to them straight away or reject them from the start, in which case you have to think of something else to quell their cries."

The use of dummies stretches back centuries with reports of infants sucking objects in the late 15th century. Soothers and comforters consisting of small linen bags filled with bread, milk and sugar were used to nourish and calm children in the late 19th century. The first patent on an India-rubber nipple similar to the present day dummy was recorded in 1845.

Today's dummies are made of latex or silicone and come in different shapes and sizes - long or short with a ball shaped or flattened end - backed by a plastic shield to prevent swallowing or choking.

Fiona Smith, children's nursing adviser at the Royal College of Nursing, said that the use of dummies varied widely between cultures, societies and communities. "It is not just about changing professional practice, it is also about changing cultural views. Many parents use dummies to calm children when they are upset. We would recommend alternatives, such as a comfort blanket or a toy."

Libby Clarke, mother, 31: 'I never liked the idea - they look horrible'

Libby Clarke from Earlsfield, south-west London, has two children - Oliver, aged two and a half, and Abigail, six months. "I never liked the idea of dummies - they look horrible. I did try one with Oliver when he was really young but he never got the idea, thank goodness. He just spat it out,'' said Ms Clarke, 31.

"When your baby is crying relentlessly and you are absolutely exhausted, you will try anything. But many parents find that once a child is used to a dummy, it is hard to give it up. Some are still running around with them at age three and four.

"It is true you can't use a dummy and suck your thumb at the same time so I suppose it might stop thumb-sucking. My baby Abigail has recently started sucking her thumb but you can't do anything about that. It seems cruel to take her thumb out of her mouth.

"I use other methods to comfort them. My son can't go to sleep without a couple of special toys, Many children need a personal comforter.

"When they were younger if they were upset I would feed them - give them a comfort suck. Abigail doesn't need that now but feeding is always a good way of calming them down.

"They both really like their bouncy chair and if we want to settle them we take them for a walk. As soon as they get in the car or the buggy they fall asleep."