By David Douglas

NEW YORK, May 19 (Reuters) For preterm newborns unable to breastfeed, cup feeding confers no benefit over other methods of supplying nutrition and may increase their hospital stay, according a review conducted by Australian researchers.

In a study published in The Cochrane Library, Anndrea Flint of the Royal Women's Hospital, Brisbane, and colleagues report that bottles and a nasogastric tube, which is inserted through the nose into the stomach, have traditionally been used in such circumstances. However, cup feeding has recently become popular.

It has been argued that cup feeding only requires infants to ''lap'' the milk and then coordinate swallowing and breathing, which they can accomplish before they are able to coordinate sucking, swallowing and breathing, the authors explain.

Conversely, others have reported that cup feeding is awkward at first and, if an improper technique is used, the infant is at risk of inhaling liquid into the lungs, which may result in a serious condition called aspiration pneumonia.

To investigate further, the team identified four studies that initially involved 472 preterm infants, born at 29 to 35 weeks gestation. The babies were randomly assigned to supplemental bottle or cup feeding.

Cup feeding initially showed an apparent advantage -- three of the studies indicated that cup-fed infants were significantly more likely to be exclusively breast-fed at hospital discharge.

Nevertheless, by 3 to 6 months, there was no longer a difference between these infants and others.

One study also showed that cup-fed infants had a 10-day longer hospital stay than did bottle-fed babies.

Commenting on the findings, Flint told Reuters Health that she and her colleagues, ''cannot recommend cup feeding over bottle feeding as a supplement because it confers no benefit in maintaining breast-feeding beyond 3 months.'' Moreover, the delay in hospital discharge caused the parents and nursing staff difficulty and they were discomfort with cup feeding.

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