Very few babies become dehydrated and seriously ill because they are not getting enough milk from breastfeeding, according to a study that calls for better support for mothers to help them establish nursing rather than resorting to formula.

Following a series of alarming stories where the plight of individual babies was described in medical journals and later in the press, doctors in Bradford and Sheffield began a study to find out how common it was for feeding to go disastrously wrong.

They collected details of every case of severe neonatal hypernatraemia – where newborn babies rapidly lose weight, become dehydrated and develop raised salt levels because they are not getting enough milk – in the UK and Republic of Ireland over one year. If not treated, the condition can lead to seizures, gangrene, brain damage and even death.

But Dr Sam Oddie and colleagues found only 62 cases from May 2009 to June 2010, a prevalence of seven in every 100,000 live births. In their paper, published on Wednesday in the Archives of Disease in Childhood and seen exclusively by the Guardian, they write that all the babies were admitted to hospital, mostly because of weight loss, and some were intravenously fed.

However, all were discharged within two days to two weeks having gained weight and none had long-term damage.

The evidence should reassure parents – but the researchers stressed it should also encourage them to seek help when struggling to establish breastfeeding. There are also milder cases of problems where babies are not feeding properly. But Oddie and other experts said the answer is not bottle-feeding but more help for women to ensure the baby attaches properly to the breast and is fed often enough.

Oddie said: "While we always expected to see low figures for this level of severity, the very nature of these cases made it important to find out exact data in order to understand what health professionals can do to better support women who breastfeed.

"This new British and Irish research helps us to understand the scale of the problem for the very first time so we can now work out what to do about it — how to spot it and how to act on it.

"If picked up soon enough, the effects are easy to reverse with a steady process of rehydration, but it is not always easy to spot as babies can look pink and alert while being on the verge of becoming critically ill.

"Measures such as early initiation of breastfeeding, skilled helpers observing and supporting women breastfeeding, and targeting help in cases where feeding is difficult – such as where there is excess weight loss, decreased stool output or both – will both support the initiation of breastfeeding in general and find cases where a more serious problem may be developing.

"As far as I'm concerned the answer isn't more formula feeding, but better support for breastfeeding from the outset. Women who are having difficulties should be monitored and helped – this is something society really needs to invest in."

Almost every baby is capable of breastfeeding, Oddie said. "In only a few cases were there special features of the baby that made it likely that there would be a severe feeding problem. [One of the babies, for instance, was found to have a cleft palate.] Normally all babies can get established with breastfeeding with the right support."

But Oddie stressed that mothers need confident and well-trained midwives, health visitors and other NHS staff to encourage and advise them. "Healthcare professionals lack confidence in their ability to know when breastfeeding is going well. I think that is interpreted by other healthcare professionals and women as a lack of confidence in the process itself."

The paper says that cases of severe hypernatraemia in the UK seem more likely to be linked to problems around getting breastfeeding established than those in, for instance, the Netherlands – where a similar study has been done.

"It is tempting to speculate that the relatively low rates of initiation and particularly continuation of breastfeeding in the UK may form part of the explanation for this," the researchers write.

"Where long-term breastfeeding is more common, both health professionals and friends and family are more familiar with it, more aware of how to do it properly and more able to pick up on problems."

Anne Woods, deputy programme manager for Unicef's Baby Friendly Initiative (BFI) – a scheme that gives accreditation to hospitals after training the staff to help mothers breastfeed – said the number of babies who could not feed was negligible and only a very small percentage – about 1% – of women would struggle to make enough milk. "The numbers who breastfeed in this country do not reflect the numbers who could breastfeed if they had effective support," she said.

Where there are problems, she added, "it fundamentally boils down to the fact that the baby is not attached to the breast effectively. The whole of the baby's mouth has to make contact and draw the breast tissue into the mouth."

But because we have a bottle-feeding culture in the UK, she said, some women do not realise this and "try to bottle-feed with their breast", so the baby takes only the nipple and does not get enough milk.

The other problem is when babies do not feed often enough. After a difficult labour or pain relief, the baby may be sleepy. There is also an expectation she said, that a baby will feed and then sleep for four hours.

Yet most adults eat or drink more than six times in 24 hours, she said -even if it is only a cup of tea and a biscuit.

In England, only 20% of hospital maternity units (accounting for nearly 22% of births) are BFI-accredited by Unicef, compared with 70% in Scotland, 60% in Northern Ireland and 40% in Wales. But problems can anyway arise once the baby goes home, because visits from midwives and then health visitors are not as common as they were.

There are danger signs that women themselves can look out for, however, and one of the most significant is the frequency of wet and dirty nappies.

There should be one soaked nappy in the first 24 hours, two in the second 24 hours and after that, half a dozen a day with tarry meconium stools showing by day three or four and yellow stools thereafter.