Clinical calculators

Estimated due date and current gestation from LMP or scan EDD.

Formula/source: Naegele rule (LMP + 280 d); standard obstetric dating.

Body mass index with recommended total pregnancy gain range.

Formula/source: BMI = kg/m2; IOM 2009 gestational weight gain guidelines.

Cervical favourability before induction.

Formula/source: Modified Bishop score (1964).

MAP; FOGSI HDP-Gestosis screening uses MAP>85 as risk point.

Formula/source: MAP = (SBP + 2xDBP)/3; FOGSI HDP GCPR risk table.

Early PPH shock detection.

Formula/source: Shock index HR/SBP; 0.9 threshold flags occult haemorrhage.

Fixed Pritchard regimen components + toxicity checklist.

Formula/source: Pritchard regimen - FOGSI-GESTOSIS-ICOG HDP GCPR 3rd Ed 2026.

Verifies the 3-hour WOMAN-trial window and dose plan.

Formula/source: WHO TXA recommendation 2017 (WOMAN); WHO Consolidated PPH 2025 Recs 27/29.

Approximate elemental iron deficit for replacement planning.

Formula/source: Simplified Ganzoni formula (factor 2.21).

Approximate PRBC units to reach a target Hb at term blood volume.

Formula/source: Standard transfusion arithmetic (blood volume ~8% body weight; unit yield ~1.4 g/dL).

Hyperglycaemia-corrected Na and AG for DKA assessment.

Formula/source: corrNa = Na + 0.016x(glucose-100); AG = Na-Cl-HCO3. Standard electrolyte formulas.

Rate-corrected QT before QT-prolonging drugs (ondansetron etc.).

Formula/source: Bazett QTc = QT/sqrt(RR s).

Treatment-dose enoxaparin by weight band (specialist confirm).

Formula/source: RCOG GTG37a-era weight-banded treatment dosing conventions.