EPV Calculator app for iPhone and iPad

EPV Calculator calculates the Estimated Placental Volume (EPV) from 2D ultrasounds of the human placenta (1).

The completely updated user interface not only calculates EPV, but plots the resultant value on a normative curve plot (2) and reports the percentile to the user. Normal EPV values are indicated in green, while values above the 90th and below the 10th percentiles are indicated in red to alert the healthcare professional of pregnancies that may need closer surveillance.

Using a simple 2D ultrasound cross-section of the major axis of a placenta from 7 to 45 weeks of gestation the Estimated Placental Volume (EPV) can be calculated from three simple measurements: maximal width, height at maximal width and thickness along the same line as the height. Measurements are recorded in centimeters.

Physicians, nurse midwives, ultrasound technicians and other health care providers can use this application to follow placental growth during gestation.

Use of this application should always be done under the supervision of a health care provider. All clinical decisions regarding any patient examined by this method should be made by the patient’s primary care giver for her pregnancy. Any EPV results should be used in combination with all other information available to the caregivers for any particular patient.


Key Features:

- Enter the patient name, gestational age in weeks and days
- Easily enter width, height and thickness of the placenta
- Calculates EPV immediately using mathematical modeling
- EPV result is immediately plotted on a normative curve, with normal values shown in green and alert values shown in red
- The EPV result and normative curves can be viewed in landscape mode for a larger plot
- Results can be easily shared using Apple’s standard share tool
- Data can be easily updated and recalculated and replotted in real-time, or cleared for a new patient


1. Azpurua HJ, Funai EF, Coraluzzi L, Sasson I, Doherty L, Kliman M, Kliman HJ. (2010) Determination of placental weight using two-dimensional sonography and volumetric mathematic modeling, Am J Perinatology, 27:151-155.

2. Arleo EK, Troiano RN, da Silva R, Greenbaum D, Kliman HJ. (2013) Utilizing 2-Dimensional Ultrasound to Develop Normative Curves for Estimated Placental Volume (EPV). Am J Perinatology, 31:683-688.