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Unlabelled: The paper is a review on the actual possibilities and indications of the transplacentar therapy of the fetus. At first some principles of the pharmacodynamics of the materno-placento-fetal unit are explained in order to enable an effective drug administration and reach therapeutic levels in the fetus. Common and less common diseases of the fetus and their therapy are exposed, such as the acceleration of lung maturation with corticosteroids, the cardioversion of tachycardias with digoxin and other antiarrhythmic drugs, the therapy of toxoplasmosis with pyrimethamine, the treatment of polyhydramnios using indomethacin, the therapy of very rare inborn errors of metabolism, the therapy of thrombocytopenia and the prevention of neural tube defects by folic acid supplementation. For these diseases the pathophysiologic background, the therapy rationale and possible side effects of therapy were exposed. Prior to an intrauterine therapy the perinatologist has to ask himself the 5 "W"-, Questions: Which fetus to treat? Why to treat? When to treat? Who will treat? Way of treatment?

The AEDV in the umbilical artery or the foetal aorta is considered to be the most severe waveform abnormality. Using pulsed Doppler, we found such a waveform in 51 foetuses out of 954 high-risk pregnancies (33/51 in both vessels, 17/51 aorta only and 1/51 umbilical artery only). A reverse flow was registered in 24 foetuses. The outcome was compared with that of a control group (n = 72) showing normal Doppler findings. The following parameters were highly significant (p less than 0.001): Rate of Caesarean section owing to foetal distress (85.3% to 4.8%), of growth retardation (IUGR) (66.7% to 6.0%), of premature delivery (73.5% to 7.5%), of low postnatal pH- and Apgar score (73.5 to 12.1%), of admission to the neonatal intensive care unit (94.1% to 8.6%), of morbidity (35.3% to 2.3%) and of mortality (41.1% to 0%). We observed 17/51 intrauterine and 4/51 postnatal deaths. The rate of malformations was 35.3% with 4 cases of aneuploidy. Considering the malformations, the rate of corrected mortality was 23%. We found, that the association of an AEDV and the absence of severe IUGR is highly suspicious of malformation. We also observed, that congenital heart diseases (CHD) could lead to an AEDV too. An AEDV precedes a pathological cardiotocogram (CTG) with a latency of 0 to 35 days (mean 9.5 days). This latency is not predictable, but we think, that a reliable assessment of jeopardy is possible by analysing further vessels (Aa. arcuatae, A. renalis, A. carotis interna): 72.5% of the foetuses with AEDV had high indices in the carotid artery and 93.1% among these showed a pathological CTG pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of foetal haemodynamics using Doppler ultrasound is widely applicable in obstetrics in assessing foetal well-being. To evaluate the parameters of foetal circulation we examined 205 pregnant women to ascertain normal velocity ranges of the foetal internal carotid artery and the foetal renal artery. By establishing the ratio between the pulsatility indices of the foetal internal carotid artery, the foetal aorta and the renal artery of the foetus, standards of these were obtained. From this it seems to be possible to gain information on the extent and degree of the centralisation of foetal blood circulation.

Blood flow velocity waveforms were recorded between the 20th and 40th week of gestation from the umbilical and fetal aorta (n = 230 each) in 130 uncomplicated pregnancies. The S/D ratio, the Resistance Index (RI) and the Pulsatility Index (PI) were calculated. In the umbilical artery the indices showed a significant decrease in the observation interval. In the fetal aorta we could not register any significant change of these indices. All values are presented as reference curves. The importance of the Doppler assessment of the circulation in these vessels for the management of high-risk pregnancy is emphasized.

Using pulsed Doppler, blood flow in the cerebral arteries was measured to assess the fetal central circulation. The Pulsatility-Index (PI) was calculated as a qualitative parameter of flow velocity waveforms. In 418 normal singleton pregnancies we performed 558 measurements between the 27th and 40th week of gestation to get normal range values of the PI. The curve shows a small decrease in the observed interval. In cases of an intrauterine hypoxia the resistance of the central vessels decrease to render the distribution of the fetal blood volume. The result of this is a centralisation of the fetal circulation. 131 high risk pregnancies were investigated and in 21 cases such a centralisation was registered. The fetal outcome of these fetuses was significantly worse compared with fetuses having a normal central flow resistance. We found for example a higher rate of caesarean sections because of fetal distress when the Pulsatility-Index was below the 5th percentile. The sensitivity of the method in prediction caesarean section for fetal distress was 59.3%, the specifity 95.3%.

Using the results of 2,130 assessments with pulsed wave Doppler-ultrasound we established an indication catalogue which reflect the availability in cases of high specificity of the method. The paper shows the modus of fetal monitoring by inclusion of the other obstetrical investigations in consequence of the Doppler-assessment and the frequency of repetition of it.

The Doppler sonography enable as a new non-invasive procedure the assessment of the uteroplacental circulation. 209 blood flow measurements (pulsed wave Doppler) were recorded between the 20th and 40th weeks of gestation from the arcuate arteries in 130 women with uncomplicated pregnancy. The S/D Ratio, the Resistance Index (RI) and the Pulsatility Index (PI) were calculated. These Indices show throughout the observation time persisting low values which reflect the optimal uteroplacental circulation in a system with low downstream impedance. We found that the S/D Ratio and the RI are appropriate parameters in the qualitative analysis of the uteroplacental perfusion. On the other side we could demonstrate that the PI depends on the maternal heart rate which explains the high variability of the values. Therefore is the PI not appropriate for the impedance measurements in uteroplacental vessels.

The use of flowmetry of the foetal renal artery offers a diagnostic improvement by analysing intrauterine centralisation of the foetal circulation. We used the examination results of 82 pregnant women, who were in intensive prenatal care, to check the prediction of foetal distress using the flowmetry of the renal artery. In foetuses showing an increased flow resistance of the aorta and a pathological flow of the renal artery, the rate of caesarian section, necessitated by foetal distress, was 63.6%. By the forming of quotients from the pulsatility indices of the internal carotid artery and the aorta on the one hand, and the renal artery and the internal carotid artery on the other hand, it seems to be possible to get information about the severity of the centralisation of the foetal circulation by existence of an intrauterine hypoxia. The rate of the operative delivery as a consequence of a foetal distress rises from 6.6% with normal PI quotients to 83.4% if both quotients are outside the double standard deviation.

The measurement of fetal and maternal blood flow velocities by Doppler-ultrasound is the first noninvasive method of studying utero-feto-placental haemodynamics. The pulsed Doppler is used by many observers to diagnose variations in the tissue resistance in certain clinical situations. The Doppler-ultrasound get the main importance in cases of intrauterine growth retardation, pregnancy induced hypertension, pregnancies in combination with diabetes mellitus and in cases of intrauterine hypoxia. This paper gives an overview about the clinical range of Doppler-velocimetry-investigations.

The paper gives an overview of the application in obstetrics of Doppler-ultrasound for blood flow measurements. Both usual methods, the continuous-wave and the pulsed Doppler are compared, including the safety aspects of the investigation. The advantages and disadvantages of quantitative and qualitative analysis of the Doppler spectrum are discussed and the necessary terms as Pulse Repetition Frequency (PRF), High Pass Filter (HPF), sample volume, aliasing and Doppler spectrum explained. The vessels of interest and the clinical importance they reflect are demonstrated. The importance of this new non-invasive mean in the assessment of utero-feto-placental haemodynamics is underlined.