Study note

Definitions of neonatal periods, live birth, and fetal death

THE CONTEXT

These definitions distinguish age periods around birth and classify birth outcomes using evidence of life, gestational age, and weight.

•

The neonatal period extends from birth to under four weeks: days 0–27 or days 1–28, depending on whether the first day is numbered 0 or 1.

•

The early neonatal period is the first week of life, less than 7 days or less than 168 hours.

•

The late neonatal period extends from 7 to 28 days.

•

The postneonatal period extends from 28 days to less than 365 days, or less than 1 year.

•

The perinatal period extends from the 22nd week of gestation to less than 7 days of life.

•

The source gives the gestational starting criterion as greater than 154 days or a fetal weight of at least 500 g.

•

Live birth is a product of conception showing any evidence of life after separation from the mother, irrespective of weight or gestational age.

•

Evidence of life includes breathing, heartbeat, umbilical cord pulsation, or definite movement of voluntary muscles.

•

Fetal death means no evidence of life after separation from the mother.

•

The stated WHO stillbirth definition is fetal death before or during birth at a gestational age of at least 28 weeks or a weight of at least 1000 g.

NEETx

Learn. Practise. Remember.