The £1.7 million refurbishment of the birthing unit at St John's Hospital in Livingston, West Lothian, has been delayed by almost three months after the project was found to be having a negative affect on the tiny patients.
NHS Lothian has been forced to fork out £76,000 to temporarily move the unit.
The health board came under fire from campaigners, who accused it of failing to properly plan for the renovation, which was taking place adjacent to the hospital's special care baby unit, where some of the region's most poorly infants are treated.
The opening of the modernised facility, which had been scheduled for the spring, has now been pushed back to June next year.
One staff member, who did not wish to be named, said the vibrations caused by building work were "echoing through the room", resulting in the babies becoming distressed.
They added: "Noise for pre-term infants causes irritability. Their sleep patterns are very sensitive to external stimulus, which is why when they're pre-term and in incubators we keep the lights low and the areas as calm as possible. The renovations were disturbing that.
"Noise can cause their oxygen saturation levels to drop as it affects their breathing and also their feeding in particular, which again is all linked to irritability. If the baby is irritable they won't eat properly, sleep properly and it all has a knock-on effect.
"I think they hadn't anticipated the vibrations. The refurbishment had been delayed for some time so when it did get the go-ahead, it was maybe rushed."
NHS Lothian insisted it had planned for the impact of noise and carried out testing, but believed adequate measures had been put in place. However, it has since been admitted that "the reality was that the prolonged nature of the noise had not been able to be tolerated".
At a meeting of the health board's finance and resources committee, incubators magnifying the effect and noise of vibration were blamed.
Gordon Beurskens, of the Action to Save St John's Hospital group, accused NHS Lothian of delivering "poor management, unnecessary waste and delayed outcomes".
He added: "Maybe the £76,000 could have been spent on baby ear protectors to drown out the noise as well as the pathetic excuses from NHS Lothian."
Frances McGuire, NHS Lothian's clinical midwifery manager, said: "Noise and vibrations were identified as a possible risk and we carried out tests before work started.
"Despite this testing, the clinical team raised concerns that the noise and vibrations may have an impact on the babies and the work was stopped immediately. The special care unit has been relocated to ensure a quiet, comfortable and safe environment.
"It is unfortunate this has resulted in a delay to the upgrading of the delivery suite but the safety and wellbeing of the babies in our care is always our top priority."