Once a foetus has been born alive, it counts as a live birth, no matter how premature.

That is to say, any foetus that takes a breath or has a heart beat or makes any muscle
after it has been delivered counts as a live birth.

In that situation, a death certificate must be provided.
  • If the infant died within 28 days of delivery, complete HP4721 (Certificate of Neonatal Death)
  • For cremation, a doctor or nurse practitioner must also complete a Cremation Certificate (Form B)

Ministry of Health
website 2018.

Ministry of Health
Guide To Certifying Causes of Death, page 17:

1. Live birth (WHO)
Live birth is the complete expulsion or extraction from its mother of a product of conception,
irrespective of the duration of the pregnancy, which, after such separation, breathes
or shows any other evidence of life, such as beating of the heart, pulsation of the umbilical cord,
or definite movement of voluntary muscles.