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🤰 Estimated Due Date (Naegele)

UseBedside dating when LMP is known. First-trimester ultrasound and ART dating take priority.

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StrataLMP dating has a wide error. ACOG prefers reliable first-trimester CRL when available.

LimitsIrregular or uncertain LMP is unreliable. · ART should be dated by oocyte retrieval/transfer. · EDD is a statistical estimate; term is ~37–42 weeks.

SourceACOG Committee Opinion No. 700. Methods for estimating the due date. Obstet Gynecol 2017;129:e150-e…

Runs locally in your browser (no PHI uploaded). For licensed clinicians — not a substitute for clinical judgement.
Stored on this device for revisit reminders

This-shift next steps

After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.

Scene next step
📋obgynOpen scene pack →
Related scores
Matching pathway
🧭eclampsiaOpen pathway →
Score + version; reference only — not a substitute for care · no HIS write

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Methodology · worked example, guidelines & full notes
Clinical takeaway

Default LMP+280 days.

When to use

Bedside dating when LMP is known. First-trimester ultrasound and ART dating take priority.

How it works

EDD = LMP + 280 days + (cycle length − 28) GA ≈ (today − LMP + cycle adjustment) / 7.

Key points

  • Default LMP+280 days.
  • Adjust by cycle − 28.
  • Optional GA versus today.

References

  • [Guideline / primary source]ACOG Committee Opinion No. 700. Methods for estimating the due date. Obstet Gynecol 2017;129:e150-e154
  • Naegele F. Lehrbuch der Geburtshilfe. 1812 (Naegele rule: LMP + 280 days)
Verification & sources · governance
FAQ

Frequently asked questions

Does Estimated Due Date (Naegele) upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
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