Before revision: Although definitions may vary among studies, most use the terms defined by the American Congress of Obstetricians and Gynecologists (1999a) to describe increased uterine activity as follows: Uterine tachysystole is defined as 6 or more contractions in a 10-minute period .
After revision: Although definitions may vary among studies, most use the terms defined by the American Congress of Obstetricians and Gynecologists (1999a) to describe increased uterine activity as follows: Uterine tachysystole is defined as more than 5 contractions in 10 minutes, averaged over a 30-minute window .