Pressure of normal uterine contractions is between 190-300. Units in terms of which units.
1 montevideo unit = Intensity of constraction x number of contractions in 10 mins.
Montevideo unit is to define uterine activity.
As per this:
Clinical labour usually commences when uterine activity reaches values between 80-120 Montevideo units (This translates into approximate 3 contractions of 40 mm of Hg every 10 minutes).
During labour – Normal uterine contractions are between 190 – 300 Montevideo units (At the time of delivery it is 300 Montevideo units)
Extra Edge

Uerine contractions are clinically palpable only after their intensity exceeds > 10 mm of Hg
Uterine contractions are not associated with pain unless their intensity is > 15 mm of Hg.
Montevideo units
Mm of Hg
Cm of water
Joules/kg