NICE NG201

Gestational Age & EDD

LMP · EDD (scan) · CRL (Robinson–Fleming)

Clinician mode

Input mode

Common pitfalls

  • LMP unreliable if irregular cycles, recent COC, or breastfeeding.
  • Always confirm with dating scan before 14/40.
  • After a first-trimester scan, do NOT re-date the pregnancy.

For educational use only

Not medical advice. Verify dosing against the BNF and your local trust guidelines before prescribing.