infant mortality rate
Last reviewed 01/2018
The infant mortality rate is the number of deaths per year under one year of age per thousand live births, including the neonatal deaths.
In England and Wales in 1989 this figure was 8.4.
The infant mortality rate varies with respect to social class of the mother - the lowest rate is seen in mothers of social class 1 (relative risk = 1). Social class II and III mothers (non-manual) have a relative risk of 1.1. Social class IV mothers (manual) have a relative risk of 1.6, and social class V mothers have a relative risk of 2.2. Higher infant mortality rates occur in illegitimate births and children born to teenage mothers.