Perinatal period

Perinatal.

This definition of perinatal period differs from that recommended by the World Health Organization (WHO). In the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems (WHO, 1992) the perinatal period is defined as commencing 'at 22 completed weeks (154 days) of gestation (the time when birthweight is normally 500 grams) and ends seven completed days after birth'.

At the time that WHO first recommended 500 grams (and now 22 weeks) as the lower limits for reporting perinatal and infant mortality, Australia had already adopted legal and statistical definitions for birthweight (400 grams) and gestational age (20 weeks) limits that were lower than the WHO limits. Also, the upper limit for the perinatal period in Australia was 28 days. These broader definitions in Australia obviously comply with, and extend, the WHO definitions.

To avoid unnecessary confusion between legal and statistical definitions in Australia, for the purposes of perinatal data collection it is recommended that the perinatal period commences at 20 completed weeks (140 days) of gestation and ends 28 completed days after birth.