Variations in number of births and perinatal mortality by day of week in England and Wales.

Analysis of the births that occurred in England and Wales during 1970-6 showed that they followed a seven-day cycle, being concentrated from Tuesdays to Fridays and least numerous on Sundays. This pattern became increasingly pronounced during the period examined. Relatively few births occurred on bank holidays, especially Christmas Day and Boxing Day. In general perinatal mortality was higher among babies born at weekends than among those born on weekdays. It is likely that the pattern seen in the numbers of births is associated to a large extent with elective intervention. It is not possible to draw any conclusions about the pattern seen in perinatal mortality as so far the analysis has been confined to crude rates.