Uterine contraction pressure is measured in terms of

Montevideo units are calculated by subtracting the baseline uterine pressure from the peak contraction pressure for each contraction in a 10minute window and adding the pressures generated by each contraction.For example, three contractions in 10 minutes, each of 50 mm Hg intensity, would equal 150 Montevideo units.Clinical labor usually commences when uterine activity reaches values between 80 and 120 Montevideo units. This translates into approximately three contractions of 40 mm Hg every 10 minutes.Reference: William&;s Obstetrics; 24th edition; Chapter 23; Abnormal Labor