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Birth risks

April 24, 2014

Your birthday was a dangerous day

Although the chance of a baby dying during birth in the UK is less than 1 in 2,000 these days, the risk is concentrated in a single day, the day of delivery.  My colleagues and I compared that daily risk of 430 per million (430 micromorts) with the chance of dying each day of the rest of our lives. Not until age 92 does the risk per day equal it.  Our paper has just been published in BJOG (click here).  It will be discussed in BJOG Twitter Journal Club #bluejc on 30 April, and for a week afterwards.

Here is the risk graph, and the main table.

daily risk graph     daily risk of death

Expressed per day – more dangerous than death row. Half as risky as climbing Everest

I had wanted to compare the risk of birth (430 micromorts) with the daily risk of execution for an inmate of death row in the United States (45 micromorts), or with a day spent above base camp on Everest (820 micromorts) but the BJOG editors dissuaded me. I wonder why!

The point remains. On the day it happens being born is one of the most dangerous things we ever do.

Jim Thornton


Micromorts – David Spiegelhalter has a wonderful site explaining them (click here).

Death row – In 2009, 3,173 inmates spent 1,158,145 days on death row, and 52 were executed (click here), a daily mortality rate by execution of 0.045 deaths per 1000 or 45 micromorts.

Everest – By 2008 there had been 4,102 successful ascents and 216 climbers had died, most in the Khumbu ice fall or at the South Col, both above base camp (click here). If 1 in 4 climbers succeed, each climber has one Sherpa and the average attempt involves eight days above base camp, that equates to 262,528 person days above base camp and a daily mortality of 0.82/1000 or 820 micromorts.

2 Comments leave one →
  1. May 1, 2014 6:55 am

    Excellent blog post, Jim, what an amazing insight!


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