Transvaginal ultrasound, endometrial cytology sampled by Gynoscann and histology obtained by Uterine Explora Curette compared to the histology of the uterine specimen. A prospective study in pre- and postmenopausal women undergoing elective hysterectomy.

BACKGROUND: The purpose of this study was to evaluate the diagnostic value of transvaginal ultrasound measurement of endometrial thickness, cytology obtained by Gynoscann, and histology of the endometrium sampled by Uterine Explora Curette compared with histology of the uterine specimen as the gold standard. METHODS: Consecutive patients admitted for hysterectomy had transvaginal ultrasound, sampling by Gynoscann, and Uterine Explora Curette done just before surgery, after informed consent. RESULTS: A total of 181 women entered the study. Sixteen had endometrial cancer, seven had atypical hyperplasia and nine had complex hyperplasia. A total of 168 patients had a transvaginal ultrasound done. At a cutoff limit of 4mm (endometrial thickness of 4mm or less indicating normal endometrium), the sensitivity was 90.3%, the specificity 24.8%, the positive predictive value 21.4% and the negative predictive value 91.9%. One endometrial cancer, one atypical and one complex hyperplasia were missed. The Gynoscann method showed a sensitivity of 62.5%, a specificity of 94.0%, a positive predictive value of 69.0% and a negative predictive value of 92.1%. Two cancers, three atypical and six complex hyperplasia were missed. The Uterine Explora Curette showed a sensitivity of 90.6%, a specificity of 100.0%, a positive predictive value of 100.0% and a negative predictive value of 98.0%. One endometrial cancer and two complex hyperplasia were missed. CONCLUSION: Transvaginal ultrasound is a reliable method in excluding endometrial pathology. The Uterine Explora Curette was superior to Gynoscann in diagnosing neoplasia of the endometrium. It was found to have the same diagnostic accuracy as conventional dilatation and curettage.

Circulatory changes in the fetal aorta after maternal smoking.

The acute cardiovascular responses of the human fetus to maternal smoking of one cigarette were studied in 10 healthy pregnant women. Following maternal smoking, a significant increase was found in the nicotine concentration in maternal plasma accompanied by a significant increase in the fetal heart rate. The flow velocity was recorded in the fetal descending aorta by combining real-time ultrasonography and the 2 MHz pulsed Doppler technique and the waveform of the maximum blood velocity was analysed. The duration of the acceleration part of the pulse cycle (start-to-peak time) remained unchanged during the study period. The least diastolic blood velocity increased significantly after smoking. The pulsatility index fell significantly during the first 5 min after smoking, probably as the consequence of fetal tachycardia, but was normal again at 10 min. The rising slope rose significantly within the first 10 to 20 min after the onset of smoking. The results indicate, that, following maternal smoking of one cigarette, fetal central circulation increases but peripheral resistance is unchanged.

A randomized study of fetal abdominal diameter and fetal weight estimation for detection of light-for-gestation infants in low-risk pregnancies.

A total of 2771 pregnant women with gestational age estimated by ultrasound measurement of the fetal biparietal diameter (BPD) before the 22nd week of gestation were re-examined by ultrasound in the 32nd and 37th week of pregnancy at which time the fetal BPD and abdominal diameter (AD) were measured. An additional examination was performed at 34 weeks if the fetal weight in the 32nd week was estimated to be less than 95% of the expected mean weight. Light-for-gestational age (LGA) was suspected if the estimated birth-weight was less than 85% of the expected mean birthweight. This applied to 186 uncomplicated pregnancies in which there was no clinical suspicion of poor intrauterine growth. These pregnancies were randomly allocated to a treatment group (AD and estimated weight reported) or to a control group (AD and estimated weight withheld). Induction of labour was significantly more common in the treatment group (41%) than in the control group (15%). No statistically significant difference was found in the use of instrumental vaginal delivery or caesarean section. There was a suggestion of marginal benefit in terms of neonatal morbidity but this was not statistically significant.

Estimation of fetal weight in the third trimester by ultrasound.

A method to estimate the intrauterine fetal weight by use of ultrasound measurements of the fetal biparietal diameter (BPD) and the abdominal diameter (AD) is presented. From a consecutive series of single pregnancies the 238 pregnancies (3% of the hospital population) with ultrasound measurements obtained within 4 days before delivery were used in the estimation of birth weight. In addition, the estimated formula was applied on a test material consisting of 100 similarly selected pregnancies from the same hospital. To evaluate the expected selection effects, the birth weight for gestational age in the study group was compared with birth weight for gestational age in the total population. The weight could be estimated as 0.0351 X AD1.65 X BPD0.69 X exp(0.00196 X gestational age). Thus, the actual birth weight was within 83-120% of the estimated weight (95% prediction limits), with a residual coefficient of variation of about 9%. The gestational age could be omitted without major influence on the weight prediction. When applying the formula on the test material, 70% of the actual weights deviated less than 10% from the estimated fetal weight, but a tendency towards a slight overestimation of the weight for light for gestational age infants was found.

On the evaluation of routine ultrasound screening in the third trimester for detection of light for gestational age (LGA) infants.

Based upon 2194 consecutive pregnancies with known gestational age, formulas for weight deviation predicted in the 32nd and 37th gestational week were estimated by multiple linear regression on the measurements of the abdominal diameter (AD) and the biparietal diameter (BPD) of the first 64% of the pregnancies. The usefulness of the screening was evaluated on the remaining 36%. An attempt to diagnose light for gestational age (LGA) infants resulted in either a low sensitivity or a low predictive value of a positive test. The late third trimester screening was more sensitive than the early, indicating LGA as a late phenomenon in pregnancy. Knowing the result from the late scanning, the result from the early scanning contributed almost no further information about whether the infant would be LGA at birth. Basic epidemiological characteristics of other comparable investigations on high-risk pregnancies and non selected pregnancies are presented.

The precision and accuracy of symphysis--fundus distance measurements during pregnancy.

We studied the precision and accuracy of SF measurements. Five trained obstetricians made three measurements of SF on each of 33 patients in the third trimester. The intraobserver variation varied from 0 cm to 8 cm, and comprised on average 1.5 to 2 cm (95th centiles 2.5 to 4 cm). The interobserver variation varied from 1 to 13 cm, and comprised on average 4 cm (95th centile 8 cm). The accuracy of SF measurements was estimated by comparison with ultrasound-guided measurements, which showed a very high precision. Two of the investigators differed significantly, by -1.56 cm and -1.97 cm, from the other 3.

Pulse wave recording--development of a method for investigating foetal circulation in utero.

The need to investigate the elastic properties of arterial vessels 'in situ' for the early recognition of degenerative disorders in arteries has long been apparent. Volume pulses in defined segments of arteries can be evaluated for this purpose, and the present paper contains a survey of earlier attempts to quantify volume pulses by means of ultrasound. A presentation is given of a recently developed digital system, comprising a phase-locked echo tracker, capable of monitoring non-invasively the diameter and its pulsatile changes of a selected artery along two chosen image lines of a linear array ultrasound scanner. The physical limitations of tracking fast-moving ultrasound echoes by means of phase-locked range gating are reported and the advantage is emphasized of using a gate length of one full period. This system has been calibrated, tested and applied in measurements of pulse wave pattern and propagation velocity in the descending aorta of human foetuses in the last trimester of gestation. The present high-resolution echo-tracking method has yielded reproducible results in the foetus and appears suitable also for screening studies on adult vessels.

Acute responses to maternal smoking of the pulsatile movements in fetal aorta.

In order to further characterize the acute cardiovascular responses of the human fetus to maternal smoking, 17 women in late pregnancy were studied after smoking a single cigarette. The pulsations of the fetal descending aorta were recorded by means of an ultrasound scanner connected to a phase-locked echo-tracking instrument; the fetal ECG was recorded from abdominal electrodes. Both the level and the wave-form of the diameter pulse curve changed typically 3-25 min after the onset of smoking, concomitant with an increase in maternal and fetal heart rate. Apparent diastolic diameter and pulse amplitude increased, while the ascending part of the curve increased in slope and decreased in duration; the late decremental velocity was reduced. The propagation time from the onset of the fetal Q-wave to the arrival of the pulse wave at the site of recording was reduced. This study demonstrates for the first time the acute effects of maternal smoking on the pulsatile dynamics of fetal vessel walls, and the method suggests the possibility of estimating changes in the contractility of the fetal heart and the afterload in the fetal circulation.

Acute effects of maternal smoking on fetal blood flow.

Thirty healthy pregnant women were studied to assess the immediate cardiovascular responses of the fetus to the smoking of one cigarette. The fetal blood flow was measured in the aorta and in the umbilical vein by combining real-time ultrasonography and the pulsed Doppler technique. Following maternal smoking, a significant increase was found in the maternal heart rate and also in the blood pressure. In the fetus, a significant transient increase in the aortic and the umbilical blood flow was measured, as characterized by the increase in the fetal heart rate, the mean and maximum blood velocity, and the vessel diameter. Thus, maternal smoking induced acute circulatory changes in the fetus similar to those found in adults. Furthermore, the study demonstrated the feasibility of the method to evaluate non-invasively the immediate effect of a given stress stimulus on the cardiovascular system of the human fetus.

Acute effects of maternal smoking on fetal heart beat intervals.

The purpose of this study was to analyse the acute effects of maternal cigarette smoking on the fetal heart beat intervals and their variability during the last trimester of a normal gestation. The fetal heart beat intervals were monitored continuously by abdominal electrocardiography for 60 min before and 60 min after smoking in 10 pregnant women. The mean intervals, their long-term variability (SD) and short-term variability (standard deviation of interval differences (SDID], calculated for 30-sec periods, showed a steady state before smoking. During the control period, the mean beat interval was negatively correlated with daily cigarette consumption and the short-term variability was positively correlated with the maternal plasma nicotine level. After smoking, the mean beat interval and the short-term variability decreased transiently, the values of both these parameters being positively correlated with the maternal nicotine values before smoking. The acute response of fetal heart beat intervals and their variability to one cigarette is distinct but transient, and the results suggest that the effects are modified by the chronic smoking habits of the women.

Physiological characteristics of diameter pulses in the fetal descending aorta.

A study was performed to establish the dynamic behavior in situ of the descending aorta in the human fetus. The pulsatile movements of the vessel walls were recorded in 36 clinically normal fetuses using a real-time phase-locked ultrasonic system measuring echo movements with high spatial and temporal resolution. The mean amplitude of the diameter pulsations was similar in the 28th - 35th week to that in the 36th - 40th week but, as the apparent diastolic diameter increased, the pulse-elicited increment of the cross-sectional area was 29% larger in the older group. The diastolic diameter decreased (p less than 0.001) and the amplitude of the diameter pulsation increased (p less than 0.001) with prolongation of the previous beat interval. The diameter pulse velocity was positively correlated to gestational age (p less than 0.001), ranging between 1.35 and 2.89 m/sec. The incremental phase of the pulse curve diminished in duration with increasing distance from the heart (p less than 0.001) and with decreasing duration of the previous beat interval (p less than 0.001). The maximum slope of the incremental phase was higher in the more distal part of the aorta (p less than 0.001). The study demonstrates that the diameter pulses contain useful information on the cardiovascular dynamics and provides evidence that the Frank-Starling mechanism is effective also in the human fetus.