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 β 3 months + 7 days. Example: LMP = March 1 β EDD = December 8.
Trimester Breakdown
- 1st trimester: Weeks 1β12 (organ development)
- 2nd trimester: Weeks 13β26 (growth, movement)
- 3rd trimester: Weeks 27β40 (weight gain, preparation for birth)