The dangers of the day of birth




To compare the risk of fetal death on the day of childbirth, with the risk of death at other ages, and with the risks of some hazardous activities, on a common scale of risk per day.


Review of publicly available data.




Data extracted from the Office of National Statistics and other sources.


Data from the Office of National Statistics and other sources were used to calculate death rates at different ages expressed as rates per day of life. Death rates for different activities were also calculated as risks per day, or risks per activity, as appropriate. All risks were expressed in micromorts, the number of one in a million chances of dying. Figures on life expectancy (LE) were used to compare potential life years lost.

Main outcome measures

Daily, or unit of activity, risk of dying for different activities compared with the risk of dying on the day of childbirth.


The risk of dying on the day of birth (0.43 per 1000, or 430 micromorts) exceeds that of any other average day of life until the 92nd year. It is comparable with other apparently more dangerous activities, such as undergoing major surgery. For comparison, the average risk of non-natural death per day and the increased risk from smoking one cigarette or travelling 200 miles by car are all about 1 micromort.


The lifetime risk of death in childbirth is low, but is concentrated in a short period, making being born a high-risk activity. Parents considering interventions to reduce these risks should be made aware of this.