Search

Electrodiagnostical determination of Rheobase and Chronaxy has been carried out on 10 women during pregnancy, beginning labour and puerperium. Rheobase and Chronaxy were marked in a Strength-Duration Curves scheme as well as some other points within that scheme. As a base of rise of the gained curves the actual rise at the point of the chronaxy was calculated. Our results show that with all 10 women the t-Difference-Test showed a significantly much lower curve during labour than that obtained during pregnancy. The same applied to the rise of the curve obtained during labour, which was significantly much lower than that during puerperium. There was no significant difference between the curves obtained during pregnancy and puerperium. The significance of the decline of the actual rise at the point of the Chronaxy of the Strength-Duration Curve before starting of labour as a physiological method of functional diagnostic will be discussed there under.

The use of electrodiagnostical investigations became more and more accepted in obstetrics within the last decade; namely rheobase measurements as a means of recognising a threatening premature labour and of checking the effectiveness of tocolytic treatment, and further as an indication of a change in the neurovegetative excitability immediately before delivery. Not only the excitability of the uterine musculature increases before onset of labour but also at the same time, the excitability of the striated skeletal musculature is raised. In obstetrics the electrical excitability usually is tested on the left musculus tibialis anterior but there is a difference in applying the electrodes (unipolar and bipolar technique). Both techniques and the basis of Electrodiagnosis are reviewed in this paper. The advantages and standardisation of the bipolar technique shall be shown.

Electrodiagnostical investigations measuring the rheobase and chronaxy as well as Oxytocin Sensitivity Tests (OST) and estimations of the pelvic score have been carried out on 19 healthy pregnant women from the 34th week on weekly and in daily intervals 1 week before the calculated date of delivery. Generally there was no trend to a decrease of rheobase until 2 days before delivery, whereas a significant drop was found between day -2 and the day of the onset of labour. At the same time the pelvic score ascended highest, but in individual cases there was no direct correlation between pelvic score and rheobase value. The OST became positive in more than 50% before the rheobase decline. Practical aspects of the combined estimation of pelvic score, OST and rheobase are discussed especially in view of the elective induction.

Electrodiagnostical investigations measuring the Rheobase and the Chronaxy have been carried out on 100 women, 36 during pregnancy, 21 during labour, 29 in puerperium and 14 with impending early delivery. As the results show, the rheobase values, which were determined during pregnancy, were significantly much higher, than those during labour or impending early delivery. The rheobase values were significantly lower during 19th--30th week of pregnancy than during 30--40th week, and the latter were significantly much higher, than those during labour or impending early delivery. In puerperium there was no significant difference of the rheobase values to those during labour, but a significant difference to the values obtained during pregnancy. The chronaxy values show no significant differences during pregnancy and labour and during pregnancy and impending early delivery. Only the chronaxy values in puerperium were significantly lower than in pregnancy as well as in labour.

The effects of oxygen and bicarbonate administration to parturients were studied by analysis of maternal and fetal blood gas parameters. Oxygen inhalation resulted in a significant increase of the fetal pO2 and appears to be a practicable mean of intrauterine reanimation of hypoxic fetuses. Intravenous bicarbonate was unable to raise the fetal pH. Simultaneous bicarbonate and oxygen administration had no desirable effects on the fetal acid-base-balance.

Urine samples from 176 healthy women between 29th and 40th week of gestation were analyzed by a test kit. Estrotec Slide Test, which offers a simple and fast test performance for estriol in pregnancy urine. The mechanism of this test system is based on a competitive latex agglutination inhibition reaction. The correlation between Estrotec Slide Test and estriol levels assayed in the same urine samples by a chemical method was r = 0,83. Variation of estriol determinations from urine and estriol levels in serum samples of women at the end of gestation measured by a radioimmunologic method was about 20% for all test principles examinated. The Estrotec Slide Test was proved to be a fast, semiquantitative method. The simple assay procedure itself imposes limits to the information available from it.

Data of 11 pregnancies (1 twin-pregnancy - 12 deliveries) achieved by in-vitro-fertilization and embryotransfer on infertile patients are reported. For most patients pregnancy was almost normal; 2 patients had threatened premature labour. In 5 cases there was evidence of moderate EPH-gestosis. In many of the women excessive weight gain was observed although estriol and human chorionic somatotrophin values were within the normal range. Intrauterine growth was normal according to echographic cephalometry. In 4 pregnancies delivery was by cesarean section after spontaneous onset of labour. All newborn babies were healthy and developed normally. The sex ratio was 7: 5 girls to boys (including one set of female twins). From fertilization the duration of the pregnancies was 265 +/- 5 days which corresponds with previous calculations based on the monitoring of ovulation. Calculated from implantation, presumably 5 days after fertilization, duration of pregnancy was 260 +/- 5 days.

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.