Montevideo units are a method of measuring

uterine The uterus (from Latin ''uterus'', : uteri or uteruses) or womb () is the organ in the reproductive system of most female mammals, including humans, that accommodates the embryonic and fetal development of one or more fertilized eggs until bir ...

performance during

labor Labour or labor may refer to: * Childbirth, the delivery of a baby * Labour (human activity), or work ** Manual labour, physical work ** Wage labour, a socioeconomic relationship between a worker and an employer ** Organized labour and the labour ...

. They were created in 1949 by two physicians, Roberto Caldeyro-Barcia and Hermogenes Alvarez, from

Montevideo Montevideo (, ; ) is the capital city, capital and List of cities in Uruguay, largest city of Uruguay. According to the 2023 census, the city proper has a population of 1,302,954 (about 37.2% of the country's total population) in an area of . M ...

Uruguay Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...

. They are exactly equal to 1

mmHg A millimetre of mercury is a manometric unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimetre high. Currently, it is defined as exactly , or approximately 1 torr = atmosphere = &nb ...

within 10 minutes. A standard adequate measurement is 200; this is generally equivalent to 27

kPa The pascal (symbol: Pa) is the unit of pressure in the International System of Units (SI). It is also used to quantify internal pressure, stress, Young's modulus, and ultimate tensile strength. The unit, named after Blaise Pascal, is an SI ...

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. Uterine pressure is generally measured through an intrauterine pressure catheter. Montevideo units can be more simply calculated by summing the individual contraction intensities in a ten-minute period, a process which should arrive at a result identical to the original method of calculation. Generally, above 200 MVUs is considered necessary for adequate labor during the active phase.

Example

If, for instance: * Peak uterine pressure amplitudes were 50 mmHg * during the 10 minute period of measurement 3 contractions occurred * subtract the resting tone from the peak intensity of the contraction * add the 3 contractions together to get the MVUs * Montevideo units are calculated by obtaining the peak uterine pressure amplitude and subtracting the resting tone. Then adding up those numbers generated by each contraction within a 10-minute window. * For example, five contractions occurred, producing peak pressures of 55, 50, 45, 65, and 50 mm Hg, respectively. The resting tone of the contractions is 10. 55-10 = 45 50-10 = 40 45-10 = 35 65-10 = 55 50-10 = 40 45+40+35+55+40 = 215 MVUs

References

External links

eMedicine
{{Pregnancy Obstetrics Units of measurement