L.A.M. Stolte

Quantitative evaluation of fetal heart rate patterns: I. Processing methods

Abstract Recording of the tachogram during fetal monitoring provides a continuous stream of data. The insight in the fetal heart action obtained with the cardio-tachogram and with the interval histogram can be greatly amplified by second order interval distribution, interval distribution in polar coordinates, histograms of the argument and the modulus, and multi dimensional approximation for the modulus and the argument. These processing methods give the advantage of data reduction and the possibility of quantification of details, whereas trends during the course of time can be detected.

Quantitative evaluation of fetal heart rate patterns

Abstract Beat-to-beat arrhythmias of fetal heart action can be hardly analysed with ordinary paper tape recordings of the fetal tachogram. This problem can be circumvented by the use of automatic processing methods by which the irregularity can be quantified and different types of irregularity can be diagnosed. Two patients are discussed. The tentative diagnosis in the first case was wandering pacemaker, and in the second one sino-atrial block.

Quantitative evaluation of fetal heart rate patterns: II. The significance of the fixed heart rate during pregnancy and labor

Abstract The heart rate patterns of anencephalic fetuses and of normal fetuses after administration of sedatives to the mother show a silent fetal heart rate pattern. In both cases, analysis of such a heart rate pattern by processing methods, shows absence of short term irregularity and the presence of only a small amount of long term irregularity.

Trend Detection in the Fetal Condition

THE CONTINUOUS recording of signals from the fetus in utero is only possible by using signals originating from the fetal heart. The fetal heart rate gives more information on the fetal circulatory condition than any other parameter associated with heart function. Therefore, in assessing the fetal condition during pregnancy and labor, the exact measurement and quantitative analysis of fetal heart rates and their disturbances are the primary objectives.

Activation of coagulation, stasis and the amniotic fluid embolism syndrome

Abstract Amniotic fluid shortens in vivo and in vitro the normal differential between intact plasma and glass-activated plasma clotting times. Intravenous injection of amniotic fluid into rabbits is followed by the formation of a clot in a segment of a previously freed jugular vein, isolated between clamps for a period of 10 minutes ( Wessler 1955). A working hypothesis for the mechanism of the amniotic fluid embolism syndrome is formulated in which enhancement of coagulation and stasis are considered of prime importance.

Experimental infarcts in the placenta of the rhesus monkey

Abstract In seven pregnant rhesus monkeys one or two maternal placental arteries in the gestational endometrium were ligated in vivo. After an interval varying between 1 1 2 and 192 hours hysterectomy was performed, leaving the placentas in situ. After a lag period of at least 23 hours necrotic lesions could be demonstrated, overlying the ligated arteries. These lesions appeared to correspond completely to the infarcts of the human placenta. The results of the experiments are discussed against the background of the modern concept of placental circulation.

The surgical accessibility of maternal placental vessels for experimental studies in vivo in the pregnant rhesus monkey

Abstract A surgical experimental technique is presented, which offers direct access in vivo to the maternal placental vessels in the endometrium of the pregnant rhesus monkey (Macaca Mulatta). In 9 monkeys a total of 15 maternal placental arteries and 9 veins were studied. All animals tolerated the operation well. The significance of this procedure for future experimental research is emphasized.

Amniotic fluid, fetal urine and clot-promoting activity

Abstract Fetal and neonatal urine shorten the recalcification time of normal citrated plasma and diminish the normal difference between the clotting times of intact and glass-activated plasma in the same way as amniotic fluid. Intravenous infusion of fetal or neonatal urine into rabbits causes similar to amniotic fluid infusion the formation of a clot in an earlier freed segment of a jugular vein, clamped during 10 minutes. Adult urine (n = 5) and fetal urine (n = 1) similar to amniotic fluid, cause an almost equal shortening of the recalcification times of plasma deficient in factor VII and normal citrated plasma.

The application of ultrasound techniques in the follow-up of a patient with a choriocarcinoma

Abstract Repeated ultrasound examination of a 32-yr-old patient with a choriocarcinoma is described. Ultrasound techniques may be a welcome addition in the follow-up of such patients.