Obstetric Calculators

Tools for pregnancy dating and assessment.

Obstetric Dating Calculator

Calculate LMP, EDD, and Gestational Age from any known parameter.

Biophysical Profile (BPP) Score

Assess fetal well-being based on five key ultrasound and NST parameters.

Component	Abnormal (0 points)	Normal (2 points)
Fetal Breathing Movements	No episode >30s in 30 min At least one episode >30s in 30 min
Gross Body Movements	< 3 discrete body/limb movements in 30 min ≥ 3 discrete body/limb movements in 30 min
Fetal Tone	Slow extension with no/partial flexion, or no movement At least one episode of active extension with return to flexion
Amniotic Fluid Volume	Largest vertical pocket ≤2 cm OR AFI ≤5 cm Largest vertical pocket >2 cm AND AFI >5 cm
Non-Stress Test (NST)	Non-reactive (fewer than 2 accelerations in 20 min) Reactive (at least 2 accelerations of 15 bpm for 15s in 20 min)

Doppler Percentile Calculator

Calculate percentiles for Umbilical Artery Pulsatility Index (PI).

Citation: Ciobanu A, Wright A, Syngelaki A, Wright D, Akolekar R, Nicolaides KH. Fetal Medicine Foundation reference ranges for umbilical artery and middle cerebral artery pulsatility index and cerebroplacental ratio. Ultrasound in Obstetrics & Gynecology. 2019 Apr;53(4):465-72.

Used with attribution. This application is not affiliated with or endorsed by FMF.

MCA Doppler Percentile Calculator

Calculate percentiles for Middle Cerebral Artery Pulsatility Index (PI).

Used with attribution. This application is not affiliated with or endorsed by FMF.

Cerebroplacental Ratio (CPR) Calculator

Calculate percentiles for Cerebroplacental Ratio (MCA PI / UA PI).

Used with attribution. This application is not affiliated with or endorsed by FMF.

Uterine Artery Doppler Calculator

Calculate percentiles for Uterine Artery Pulsatility Index (PI).

Citation: Cavoretto PI, Salmeri N, Candiani M, Farina A. Reference ranges of uterine artery pulsatility index from first to third trimester based on serial Doppler measurements: longitudinal cohort study. Ultrasound in Obstetrics & Gynecology. 2023 Apr;61(4):474-80.

Used with attribution. This application is not affiliated with or endorsed by the author.

More Calculators Coming Soon

Additional obstetric tools are under development.

Disclaimer

All calculations must be confirmed before use. The estimated results are not a substitute for clinical judgment.

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