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Due Date (Estimated Date of Delivery)

The projected date a pregnant person is expected to give birth, calculated as 280 days (40 weeks) from the first day of the last menstrual period.

The due date (EDD) is an estimate β€” only about 4% of babies are born on their exact due date. Most are born within Β±2 weeks.

Naegele's Rule

EDD = LMP + 1 year βˆ’ 3 months + 7 days. Example: LMP = March 1 β†’ EDD = December 8.

Trimester Breakdown

  • 1st trimester: Weeks 1–12 (organ development)
  • 2nd trimester: Weeks 13–26 (growth, movement)
  • 3rd trimester: Weeks 27–40 (weight gain, preparation for birth)

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