Monitoring Uterine Contractions in Montevideo Units (MVU)

Method:

(1) The patient has an intrauterine pressure catheter (IUPC) be in place to measure the pressure during each contraction in mm Hg.

(2) Continuous recording of the pressure tracing is made over a 10 minute period.

uterine contractions in Montevideo Units (MVUs) =

= SUM((peak pressure reading for each contraction in mm Hg during a 10 minute period) – (resting pressure reading in mm Hg))

Alternatively:

uterine contractions in Montevideo Units (MVUs) =

= ((peak pressure reading for first contraction in mm Hg) – (resting pressure reading after the contraction in mm Hg)) + ….+ ((peak pressure reading for the last contraction during the 10 minute period in mm Hg) – (resting pressure reading after the contraction in mm Hg))

Interpretation:

• Caldeyro-Barcia and Alvarez reported that contractions in the range 150 – 250 MVUs was associated with normal progression of labor. Readings tend to be lower at the beginning of labor and increase with cervical dilatation and pushing.

• Hypocontractile labor overlaps with normal labor

from Murray and Urbanski, page 54.