[Neuromuscular excitability and duration of labor. Rheobase before and after amniotomy for induced labor]

In 12 primiparae who--on term--did not have spontaneous contractions but a Bishop score greater than 7, Rheobase was measured and there after labour induced by amniotomy. A second evaluation of Rheobase followed one hour after amniotomy. Results show that one hour after rupturing the membranes the Rheobase values decreased significantly (p less than 0,01). The correlation between initial Rheobase values and duration of delivery was still more significant (p approximately 0,001). The possible importance of Rheobase evaluation in the selection of pregnant women on term for elective induction (baby by appointment) is discussed.