Estimated Placental Volume (EPV)

Dr. Harvey Kliman, working with his father, mathematician Merwin Kliman, has developed a technique to measure Estimated Placental Volume (EPV) during pregnancy. This information has the potential to improve patients' prenatal care and pregnancy outcomes, as small placentas can lead to intrauterine growth restriction, and in severe cases, even intrauterine fetal demise.

EPV can be measured from 7 to 40 weeks. Use widest angle probe for large placentas. Beyond 36 weeks the placenta may be too large to visualize the entire width.

Ideal measurements: Freeze a perpendicular cross section at the maximal width of placenta. Take Width measurements from edge to edge. Start at apex and measure Height and Thickness down to baseline along same line (at right angles to Width line). Height is always greater or equal to thickness.

To download the simple one-page manual click here

To download the detailed eleven-page manual To download the detailed eleven-page manual click here.

The EPV ResearchKit app is designed to allow patients to contribute to research on the relationship between placental volume and a healthy pregnancy. Once downloaded, the patient asks their healthcare provider to measure the width, height and thickness of their baby's placenta and enter the results in the data entry screen.

Placenta is an obvious crescent. Baseline Width is measured from tip to tip (+), yellow line.

Apex is found and Height is measured from apex to baseline (⸭), yellow line perpendicular to Width line.

Thickness is measured starting from same apex point as Height and then measured along the same line down to edge of placenta (✕), orange line.

Placenta is flat, without any evidence of curvature. The maximal Width is measured from tip to tip (yellow). The Height and Thickness (orange) are the same and are measured once to obtain both values.

See Azpurua et al. (2010) Determination of placental weight using two-dimensional sonography and volumetric mathematic modeling, Am J Perinatology, 27, 151-155 for details. Find the calculator here.

Azpurua HJ, Funai EF, Coraluzzi L, Sasson I, Doherty L, Kliman M, Kliman HJ. Determination of placental weight using two-dimensional sonography and volumetric mathematic modeling, Am J Perinatology, 27: 151-155, 2010.
Kliman HJ, Arleo EK, Troiano RN. Development of In Utero Normative Placental Growth Curves Using a Validated Mathematical Model, ACOG 59th Annual Meeting, April 30 to May 4, 2011, Washington, DC
Staff AC, Laine K, Lahmami G, Gustafsson J, Surbehan H, Barbero ML, Kliman HJ. Second trimester estimated placental volume (EPV) screening is predictive of SGA and LGA at birth. International Federation of Placenta Associations, September 13-17, 2008, Geilo, Norway.
Arleo EK, Troiano RN, da Silva R, Greenbaum D, Hartigan JA, Ge W, Zeissler AG, Kliman HJ. Estimated Placental Volume (EPV): Set a Competitive New Standard of Prenatal Care in Less Than One Minute. Radiologic Society of North America, November 27-December 2, Chicago, IL.
Arleo EK, Troiano RN, da Silva R, Greenbaum D, Kliman HJ. Utilizing 2-Dimensional Ultrasound to Develop Normative Curves for Estimated Placental Volume (EPV). Am J Perinatology. 2013 Oct 9. [Epub ahead of print]
Sonek J, Krantz D, Carmichael J, Downing C, Jessup K, Haidar Z, Ho S, Hallahan T, Kliman HJ, McKenna D. (2018) First trimester screening for early and late preeclampsia using maternal characteristics, biomarkers, and estimated placental volume. American Journal of Obstetrics & Gynecology, 218:126.e1-126.e13; doi: 10.1016/j.ajog.2017.10.024
Isakov KMM, Emerson JW, Campbell KH, Galerneau F, Anders AM, Lee YK, Roberts AE, Kliman HJ. (2018) Estimated placental volume and gestational age. American Journal of Perinatology, 35:748-57, 2018; doi: 10.1055/s-0037-1615285