The inquiry ruled "defects" within the system contributed to each death, including that there was a "lack of an effective means" to highlight risks in one of the pregnancies and that midwives had no guidance to assess preterm labour symptoms.
Sheriff Principal Aisha Anwar KC made 11 recommendations for the future, including creating a "trigger list" to identify and assess early labour symptoms.
Among these are reviewing electronic patient information records to improve alerts for at risk mothers, and having a direct telephone line to each maternity unit in Scotland for ambulance crews.
In a statement, the McCormick family said: "The family could simply never have imagined the scale of both the individual and systems failures that came to light during the inquiry.
"What seemed to be flaws with the electronic system of record keeping actually turned out to be a catalogue of errors with numerous opportunities to avoid the tragic outcome that followed.
"It was extremely difficult for the family to hear the evidence and reading the determination is bittersweet in terms of achieving some sense of closure but also learning once again how different things ought to have been."
The family added they hoped all the inquiry's recommendations would be implemented.