Uterine tachysystole is defined as 6 or more contractions in a 10-minute period . Uterine hypertonus is described as a single contraction lasting longer than 2 minutes. Uterine hyperstimulation is when either condition leads to a nonreassuring fetal heart rate pattern. The American Congress of Obstetricians and Gynecologists amended these definitions in 2008. Uterine tachysystole is defined as  5 or more contractions in 10 minutes, averaged over a 30-minute period. The terms "hypertonus" and "hyperstimulation" are not recommended to be used.
Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute window . Uterine hypertonus is described as a single contraction lasting longer than 2 minutes. Uterine hyperstimulation is when either condition leads to a nonreassuring fetal heart rate pattern. The American Congress of Obstetricians and Gynecologists amended these definitions in 2008. Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute period. The terms "hypertonus" and "hyperstimulation" are not recommended to be used.
R
6 or more contractions in a 10-minute period
more than 5 contractions in 10 minutes, averaged over a 30-minute window
A
more than
D
or more