Only about 4 to 5 percent of babies are born exactly on their estimated due date. This low percentage reflects the natural variability in pregnancy length and the fact that due dates are estimates rather than precise predictions

. Most babies are born within a two-week window before or after the due date, with about 68% born within 11 days of the estimated due date as calculated by early ultrasound

. Additionally, around 70% of babies are born before their due date, with many deliveries occurring around the 39th week of pregnancy rather than exactly on the due date

. In summary, the due date serves as a guideline for care rather than a strict deadline, and only a small minority of babies arrive precisely on that day.