Uterine contractions during pregnancy.

The principal function of muscular tissue is contraction. This is also true for the uterus this function begins with sexual maturation. During pregnancy special conditions are brought about by the increasing distention of the uterine cavity. For clinical practice, external tocography is of importance for the recognition of uterine motility Data in the literature on the normal frequency of contractions during pregnancy vary greatly and caused us to study this topic. Moreover, most cases of prematurity independent of other causes suppose a prematurely increased uterine motility. In order to register this activity a portable recording apparatus was developed. We studied in particular the question for how long and how often uterine contractions should be recorded. A one hour daily recording was found to be sufficient. In order to gain information on the average number of contractions it suffices to record during one week. In 26 healthy primiparous and 28 multiparous women the number of contractions from the 25th to 41st gestation week was recorded. A notable finding was the frequency peak about the 32nd week. The number of pregnancy contractions as a sole parameter for the recognition of impending premature delivery is not sufficient. However, the information may be important when taking in conjunction with the previous history and the state of the cervix. We considered tocolysis indicated when as a weekly average there are more than two contractions per hour with beginning cervical dilation or more than three contractions per hour regardless of cervical findings.(ABSTRACT TRUNCATED AT 250 WORDS)