Where are the Sunday babies? Observations on a marked decline in weekend births in Germany

In 5-year intervals, data from 722,306 individuals born between 1988 and 2003 in North Rhine Westphalia, Germany's largest state, were analyzed for the weekday of birth. In contrast to data from 1900 to 1950 (n=149,267), serving as historical controls, a very marked nonrandom distribution was discovered, with decreasing numbers of births on weekends, especially on Sundays, reaching deviations from the expected distribution of -17.8% in 2003, while births on weekdays are more frequent than expected (Fridays: +8.1% in 2003). The increasing avoidance of births during weekends by elective labor induction on weekdays is discussed as a consequence of practical and increasing financial constraints of hospitals.