They were created in 1949 by two physicians, Roberto Caldeyro-Barcia and Hermogenes Alvarez, from Montevideo, Uruguay.
A standard adequate measurement is 200; this is generally equivalent to 27 kPa of combined pressure change within 10 minutes.
Units are directly equal to pressure change in mmHg summed over a ten-minute window.
It is calculated by internally (not externally) measuring peak uterine pressure amplitude (in mmHg), subtracting the resting tone of the contraction, and adding up the numbers in a 10-minute period.
[2] Generally, above 200 MVUs is considered necessary for adequate labor during the active phase.