Margaret Marin's "shocking" dishonesty meant the normally busy ward at St John's Hospital in Livingston, West Lothian, was closed to pregnant women for more than five hours and a neighbouring maternity unit that was struggling to cope with its workload could not transfer patients.
The scam was only spotted thanks to an alert doctor at another hospital who realised the medical records of the invented patients did not make sense.
Andrew Gibson, a lawyer with the Nursing and Midwifery Council (NMC), said: "We don't know what would have happened that night if it wasn't for that doctor raising the alarm."
Ms Marin was sacked by NHS Lothian and charged by the NMC following the scandal in May 2012 at St John's, which has also been at the centre of a gagging row after whistleblower Dr Jane Hamilton raised concerns about the running of the mother-and-baby unit more than five years ago.
The 54-year-old chose not to appear at the hearing in Edinburgh this week but admitted entering false information for four patients and accepted that her behaviour was "dishonest".
Mr Gibson, who presented the case for the NMC, said that an investigation by the hospital had found that Ms Marin had failed to put patient care first by not realising the risks involved with her "fraudulent behaviour".
He said: "She falsely entered the data onto the hospital floor plan system, which can seen by all hospitals in NHS Lothian, making the ward look busier than it was."
Mr Gibson added: "It was simply a case of wanting to give her staff a quiet night. She has admitted that her conduct was dishonest. She failed to see how her actions may have impacted on the women and the care that they would have been able to receive.
"She lost sight of her overriding duty of care to patients on a misguided wish to give herself and her staff an easy ride. She had an early opportunities to come clean and she chose not to take those early opportunities."
Mr Gibson said the maternity unit at the Royal Infirmary of Edinburgh was dealing with two high-dependency cases that night and wanted to transfer pregnant women to St John's. "There was clearly some concern coming from the ERI just as to what the situation was," said Mr Gibson. "It was only resolved when a doctor noticed discrepancies on the medical records of the patients that were apparently at St John's hospital."
In an email to the NMC, Ms Marin wrote: "I will not attend any more hearings about this case. Not because I don't wish to face up to my responsibilities but because I have no question about what the outcome will be."
Sarah Ballard-Smith, Nurse Director, NHS Lothian, said: "This incident was fully investigated and swift and decisive action was taken at the time."
The NMC is expected to decide today what sanction to apply against Ms Marin.