Medical calculators
EDD / Gestation
Naegele Rule
For education. Check every result.
Anatium is a study resource, not medical advice. Nothing here is a diagnosis, a prescription or a substitute for a clinician who has seen the patient. Check every number against a current local protocol before it touches anyone, and never act on a result you cannot reproduce yourself.
How it is calculated
Naegele rule: LMP plus 280 days. It assumes a regular 28-day cycle with ovulation on day 14, so it is unreliable with irregular cycles, recent hormonal contraception or uncertain dates - first-trimester ultrasound is more accurate and takes precedence where the two disagree.
About
Estimated due date from the last menstrual period. Assumes a regular 28-day cycle; a first-trimester scan takes precedence.
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