Wolfgang Hütter

DOPPLER SONOGRAPHIC FINDINGS AND THEIR CORRELATION WITH IMPLANTATION IN AN IN VITRO FERTILIZATION PROGRAM.

In 45 women from an in vitro fertilization (IVF) program, the uterine and ovarian blood flows were investigated by vaginal Doppler sonography. The resistance index was used to evaluate the blood pattern. When comparing the patients who became pregnant after embryo transfer (ET [group I, n = 12]) with those who did not conceive (group II, n = 33), it is evident that in group I the vascular resistance of the uterine arteries is significantly lower on the day of follicular aspiration. No differences could be detected in the ovarian vessels. The data obtained so far suggest that the receptivity of the endometrium is a crucial factor for successful implantation. In the final analysis, this can be appraised not only on the basis of morphological but also of hemodynamic parameters.

Cross-conjugated compounds: microwave spectrum of 4,4-dimethyl-2,5-cyclohexadien-1-one

Abstract 4,4-Dimethyl-2,5-cyclohexadien-1-one has been prepared by a three-step reaction from 4,4-dimethyl-2-cyclohexen-1-one. Microwave transitions of the cross-conjugated compound have been measured over extended regions from 11 to 40 GHz. The spectrum is a classical a-type spectrum of a near-prolate top with many interspersed lines presumably originating from excited vibrational states. No internal rotation splitting could be observed. We were able to assign 108 rotational transitions with J-quantum numbers up to 40. The least-squares fit showed a standard deviation of 30 kHz and yielded the three rotational constants, A = 3332.158(13) MHz, B = 1193.07386(52) MHz, C = 1082.21280(45) MHz, as well as all five quartic centrifugal distortion constants from Watsons A-reduction: ΔJ = 0.02149(73) kHz, ΔJK = 1.1008(16) kHz, ΔK = −68.42(32) kHz, δJ = 0.00332(16) kHz, δK = −2.7513(99) kHz (representation IR used). The dipole moment was determined from the Stark shift of the M-components of two transitions and was found to be 4.4522(83) D from 93 measurements.

Cross-conjugated compounds: microwave spectrum and ring planarity of 3-methylene-1,4-cyclohexadiene

Abstract The unstable 3-methylene-1,4-cyclohexadiene, an isomer of toluene, has been prepared from benzoic acid. The hydrocarbon can be handled quite easily in the solid state, and in the gas phase at low pressures. Rotational transitions have been measured from 12 to 40 GHz. Sixty-three lines were assigned with J-quantum numbers up to 60. From the least-squares fit with a standard deviation of 23 kHz the three rotational constants and all five quartic centrifugal distortion constants from Watsons A-reduction could be determined as A = 5177.8216(37) MHz, B = 2613.1518(10) MHz, C = 1755.8422(9) MHz, Δj = 0.1384(65) kHz, ΔJK = 0.135(16) kHz, ΔK = 1.074(50) kHz, δJ = 0.0440(11) kHz and δK = 0.333(24) kHz (representation IR used). The dipole moment was found to be 0.8645(31) D from 32 frequency shifts in total of the M components of the transition 835 ← 734. The 6-monodeuterated species has also been prepared and its microwave spectrum measured. Using Kraitchmans equations, the coordinates of the ring methylene hydrogens could be determined. The pseudoinertial defect was found to be −0.1435(56) A2 which proves that the molecule possesses a planar ring. The results are compared with the data for 4,4-dimethyl-2,5-cyclohexadien-1-one.

Reference values for resistance index and pulsatility index of uteroplacental Doppler flow velocity waveforms based on 612 uneventful pregnancies.

Using a 4-MHz continuous-wave Doppler device, standard rates were established for resistance index (RI) and pulsatility index (PI) of uterine and arcuate arteries of 612 patients with uneventful pregnancies and deliveries. From 18 to 41 weeks of gestation, neither RI nor PI of uterine or arcuate arteries proved to vary with gestational age, maternal heart rate, or maternal age. By contrast, a significant effect of placental location on the measurement results was found in both uterine and arcuate arteries. The differences between measurements on the placental or opposite site are more distinct in arcuate than in uterine arteries. Taking the 90th percentile as a localization gauge, cutoff levels of 0.52 (RI) and 0.98 (PI) were found in uterine arteries. In arcuate arteries, cutoff levels of 0.45 (RI) and 0.82 (PI) were found on the placental site or with a placenta without lateralization. On the nonplacental site of a lateralized placenta, the cutoff levels were 0.51 (RI) and 0.92 (PI).

Planarity of conjugated cyclic systems and prediction of rotational constants : ab initio and semi-empirical calculations of some cross-conjugated compounds

Abstract Ab initio and semi-empirical calculations have been carried out on six cyclic cross-conjugated compounds: fulvene, cyclopentadienone, 2,5-cyclohexadienone, 4,4-dimethyl-2,5-cyclohexadienone, 3-methylene-1,4-cyclohexadiene and 3,3-dimethyl-6-methylene-1,4-cyclohexadiene. The results are compared with experimental data as far as it is available.

Continuous-Wave Doppler Investigation of Uteroplacental Vessels in High-Risk Pregnancies as Predictor of Fetal Growth Retardation and Pregnancy-Induced Hypertension

Continuous-wave Doppler sonography of uteroplacental vessels and the umbilical artery was used as an additive method in the management of risk pregnancies. Its major advantage lies in permitting noninvasive access to placental perfusion. In a sample of 650 singleton pregnancies considered at risk, flow patterns of the right and left uterine and arcuate arteries and of the umbilical artery were obtained. Increased resistance in uteroplacental circulation alone (90th percentile of resistance index and/or notching) was seen in 62 of 100 patients with confirmed growth retardation, proving the key role played by uteroplacental perfusion disorders. Early diastolic notching as well as incomplete vascular flow patterns were also found significantly more often in the growth-retarded group compared to the controls, especially in pregnancies additionally beset by hypertensive disorders. Doppler study of both utero- and fetoplacental circulation increased the sensitivity to 76% in pregnancies with intrauterine growth retardation, and to 90% in those cases with an additional risk of pregnancy-induced hypertension, while the false-positive rate (100-specificity) remained acceptable (17%).

Polynomial Analysis of Placental Flow Patterns in Growth-Retarded Fetuses

Correct interpretation of conspicuous blood flow velocity waveforms cannot rely solely on the evaluation of uteroplacental vascular Doppler flow patterns by means of angle-independent indices such as the resistance or pulsatility index. In addition to the degree of pulsatility, the waveform shape between the systolic and diastolic peak values is of considerable consequence. A subdivision of the total flow waveform into orthogonal polynomial components allows both pulsatility evaluation and notching to be registered, providing a higher sensitivity in identification of pathological vascular resistance. Accurate recording and assessment of the flow waveform is therefore an important qualitative criterion for the classification of Doppler flow patterns in pregnancies with reduced uteroplacental perfusion.

Uteroplacental diastolic notching in 510 uneventful pregnancies

In a collective of 510 patients with uneventful pregnancies and deliveries the rate of waveform notching in the uteroplacental flow velocity pattern was examined. Notching appeared to be significantly more frequent in the uterine than arcuate artery. It was unilateral and mainly affected placenta-contralateral sites. Bilateral notching or notching on placental site were the exception. In both flow patterns notching was seen to increase as pregnancy progressed and was slightly higher in the third compared to the second trimester.

Frühdiastolische Inzisuren in uteroplazentaren Gefässen

In einem Kollektiv von 510 Patientinnen mit unauffalligem Schwangerschafts- und Geburtsverlauf wurde die Haufigkeit von Inzisuren im uteroplazentaren Stromgebiet untersucht. Dabei war die Arteria uter