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Our purpose was to determine whether the Doppler cerebroplacental ratios predicts perinatal outcome in postterm pregnancy. The middle cerebral to umbilical artery resistant and pulsatility indices (MCA PI/UA PI and MCA RI/UA RI) were measured in 59 postterm pregnancies. We found significant correlation between MCA PI/UA PI, MCA RI/UA RI, nonstress testing and intrapartum fetal heart rate assessment. There was also an association between MCA PI/UA PI and 1- and 5-minute Apgar score. We conclude that the Doppler cerebroplacental ratios provide useful information about perinatal outcome.

Objective: Recent studies have documented increased perinatal morbidity and mortality rates in the growth-restricted postterm fetus. Our purpose was to evaluate the receiver operating characteristic curve of ultrasonographically estimated fetal weight as a predictor of fetal growth restriction in prolonged pregnancies., Study Design: Fetal weight was estimated ultrasonographically within 9 days of delivery (mode 1 day) in members of a cohort of 410 patients with prolonged pregnancies (>41 weeks). Estimated fetal weights were compared with birth weights in receiver operating characteristic curve analysis., Results: The areas under the receiver operating characteristic curves for predicting birth weights <10th percentile (3125 g in this population) and <5th percentile (2930 g in this population) were 0.89 and 0.96, respectively. Both areas were significantly different from an area indicating a useless test. The estimated fetal weight values corresponding to the inflection points for the receiver operating characteristic curves predicting birth weights <10th percentile and <5th percentile were 3370 and 3200 g, respectively. With estimated fetal weight at less than these test cutoff values, the relative risks for a fetus to have a birth weight <10th percentile or <5th percentile were 14.6 (95% confidence interval, 6.25-33.8) and 89.8 (95% confidence interval, 12.1-665), respectively. Analysis of the receiver operating characteristic curves resulted in improved test characteristics relative to using the actual 10th and 5th birth weight percentiles as cutoff values for estimated fetal weight (relative risk of 14.6 vs 9.5 and 89.8 vs 26.0, respectively)., Conclusions: Ultrasonographic estimation of fetal weight is a useful test for predicting fetal growth restriction in prolonged pregnancies. Future studies should evaluate whether intervention on the basis of this identification results in improved perinatal outcome.

Objective: To investigate the association between fetal, umbilical and uterine circulatory changes and adverse perinatal findings in very prolonged pregnancies., Study Design: 44 women proceeding to 43 completed weeks of gestation with the intention of a trial of vaginal delivery were studied prospectively with ultrasound Doppler velocimetry. An intensified fetal surveillance was routinely commenced at 42 weeks and only uncomplicated pregnancies were allowed to proceed. The endpoint perinatal measures were oligohydramnios, fetal meconium release, fetal distress in labor and birth asphyxia. Flow variables in different groups were compared with the Mann-Whitney U test, Student's unpaired t-test, Wilcoxon signed-rank matched-pairs test, Fisher's exact test and contingency table analysis, and a two-tailed P value <0.05 was considered statistically significant., Results: The umbilical artery pulsatility index was significantly lower in cases of fetal meconium release (n=12) and fetal distress (n=7). The umbilical venous flow velocity was significantly lower in cases of meconium, and the fetal aortic volume flow significantly higher in cases of fetal distress. No significant flow changes were found in connection with oligohydramnios (n=5) and birth asphyxia (n=2). Uterine flow was not significantly affected in any group., Conclusions: In very prolonged pregnancies, fetal distress in labor was not associated with an increased placental vascular resistance. In contrast to previous reports, the umbilical artery pulsatility index was low in cases of fetal distress and meconium release. The etiology is unknown, but a subclinical fetal hypoxia might have triggered a vasodilation of placental vessels. Vasodilation at an unchanged volume flow could also explain the decrease of umbilical venous flow velocity. The increased aortic volume flow indicates an increase of cardiac output in fetuses later developing distress in labor.

A total of 153 pregnant women, of at least 287 days' menstrual age, were studied in a prospectively designed cross-sectional trial. In addition to the non-stress test, contraction stress test, sonographic estimate of amniotic fluid and grade of placental maturation, Doppler measurements of the resistance index (RI) were taken in the umbilical artery, the uteroplacental arteries in the region of placental implantation and the fetal middle cerebral artery. Data were analyzed with regard to asphyxia and otherwise complicated fetal outcome. Furthermore, a possible relationship between grade of placental maturation, Doppler flow velocity waveforms and fetal outcome was investigated. Doppler resistance indices in the umbilical artery, uteroplacental arteries in the region of placental implantation and fetal middle cerebral artery did not change significantly with increasing gestation from 41 to 43 weeks. The grade of placental maturation on ultrasound examination was not related to fetal outcome or Doppler indices in the first two vessels. In all vessels examined in this study, the majority of Doppler measurements in pregnancies with subsequent asphyxia or otherwise complicated fetal outcome were within the 95% prediction interval for patients with normal fetal outcome. None of the patients showed absent diastolic flow in the umbilical artery. With the use of a cut-off value of RI = 0.62 in the umbilical artery, asphyxia could be predicted with 37% sensitivity and 75% specificity. Oligohydramnios and antpartum cardiotocography predicted asphyxia with 16% and 8% sensitivity and 95% and 96% specificity, respectively. Sensitivity for prediction of otherwise complicated fetal outcome by umbilical artery Doppler was only 7%.(ABSTRACT TRUNCATED AT 250 WORDS)

There have been various estimations of the frequency of postdate pregnancies. On the average, 10% of all pregnancies exceed 42 weeks amenorrhoea with a range from 4 to 14% according to the authors. Rates vary with use of ultrasound examinations early, avoiding false dating and induced labour. A pregnancy becomes a pregnancy at risk at the end of the 41st week of amenorrhoea. Fetal maturity may be affected by a disease process or due to individual or ethnic variations. The potential danger of prolonged pregnancy is inhalation of meconium prepartum. Expulsion of meconium is both a frequent consequence of fetal distress and the result of increased intestinal reactivity. There does not appear to be agreement on the degree of risk of sudden death at the end of pregnancy, although the risk does appear to exist. Surveillance should include recording fetal heart rate under basal conditions and an assessment of the amniotic fluid volume with ultrasounds. The Doppler technique is currently under study. When the status of the cervix is favourable, labour may be induced by rupturing the membranes of with a perfusion of Syntocinon. When the status of the cervix is unfavourable, prostaglandin E2 is applied intravaginally or intracervically with a gel. Therapeutic trial published to date do not demonstrate any advantage over cesarean section or fetal morbidity. The safety of the procedure has not been proven. Randomized trials comparing systematic induction of labour with a wait-and-see attitude have not given a definitive answer. Only two trial have shown a significant advantage of systematic induction of labour. The others have shown that the rate of cesarean section and neonatal morbidity are comparable in the two groups.

Based on 132 histomorphological placental investigations and their related Doppler test results, the question was asked, whether a strong correlation exists between Doppler test results and histomorphological placenta results, and whether these are uniform with respect to histomorphological changes. The results showed that all histomorphologically inconspicuous placenta findings were also inconspicuous doppler-sonographically. The viewing resulted in no histomorphologically unifying aspect of change. However, the investigation was able to demonstrate, that a distinction must be made between acutely developing changes and chronically developing changes. Along these lines, the last groups produced not only changes which compensate each other, but also changes, which are harmful to organic functioning and thus may diminish foetal supply without being detected by pulsed Doppler ultrasound.

Doppler sonography can help to assess a foetal risk situation prospectively. This procedure is therefore well suited for the screening of risk pregnancies in the 3rd trimenon. The role of Doppler ultrasound at delivery is still controversial, since, on the one hand, no data on the behaviour of Doppler parameters directly at the onset of delivery are available, and on the other hand the obstetric consequences from pathological findings are not clear. For this reason, we observed 45 normal pregnancies from the 10th day prior to the date of confinement till the 10th day post partum. In 20 patients we registered Doppler parameters from 4 days before until the onset of true labour. In all these cases, a reduction of the end-diastolic blood flow in the foetal aorta was found, which became evident by the increase of the resistance index to pathological values. Concomitant decrease of the resistance index in the foetal carotid artery was typical for a circulatory system. Since foetal outcome was normal in all newborn, this change in Doppler parameters directly at the beginning of labour must be considered as physiological. The findings suggest a physiological placental insufficiency. Since however, parameters in the uterine vessels did not show any changes, the insufficiency has its probable origin in the placenta. From these findings, one might speculate, that the supply deficiency is the labour inducing factor. No clinical consequence can thus result from pathological Doppler data found in patients directly prior and after delivery. Cardiotocographic screening is necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: Our purpose was to determine Doppler waveforms of the fetal human renal artery in prolonged pregnancy in the presence or absence of oligohydramnios., Study Design: Fifty patients at or after 40 weeks were studied. Ultrasonography was performed to determine the amniotic fluid index by the four-quadrants technique. Two groups of patients were obtained on the basis of the amniotic fluid index. Group 1 had an amniotic fluid index > 5 (normal) (n = 33); group 2 had amniotic fluid index < or = 5 (oligohydramnios) (n = 17). Umbilical artery and fetal renal pulsed Doppler waveforms were determined and analyzed. The fetal renal artery systolic-to-diastolic ratio of the two groups was compared., Results: Fetuses with a low amniotic fluid index had a significantly higher ratio. A significant negative correlation coefficient between amniotic fluid index and fetal renal systolic/diastolic ratio was found (r = -0.435 and p < 0.01)., Conclusions: In prolonged pregnancies there is a significant relationship between the amniotic fluid index and the fetal renal systolic/diastolic ratio. In pregnancies associated with oligohydramnios the systolic/diastolic ratio is significantly higher than in those with normal amniotic fluid volume. These data suggest that intrarenal flow in prolonged pregnancies complicated with oligohydramnios is significantly different.

The capability of Doppler flow velocimetry to predict intrauterine growth retardation is well known. The increased morbidity and mortality rate of postterm newborns is also well known. The aim of our study was to examine if Doppler flow velocimetry is able to indicate foetal jeopardy in the postterm period. Flow velocimetry of the foetal descending aorta, the umbilical artery, the uterine arteries and in 59 cases also the foetal middle cerebral artery was obtained from 167 pregnancies after 40 completed weeks of gestation. We found significant changes of normal values in prolonged pregnancy compared to third trimester normal values, examining the mean velocity of the foetal descending aorta and the S/D-ratio of the umbilical artery. No clinically significant changes were found examining the S/D-ratio of the uterine arteries and the pulsatility index of the foetal middle cerebral artery. Daily examinations of the foetal descending aorta were carried out in 23 and of the umbilical artery in 19 cases during the last four days before delivery, and in 11 cases of the foetal middle cerebral artery during the last three days before delivery. We did not find significant changes in the medians of the mean velocity of the foetal aorta, of the S/D-ratio of the umbilical artery and of the pulsatility index of the foetal middle cerebral artery. Measurement of sensitivity and positive predictive value of the four arteries examined showed, that Doppler ultrasound could not predict small for date infants or Caesarean section because of foetal distress.(ABSTRACT TRUNCATED AT 250 WORDS)

Objective: To determine the amniotic fluid (AF) volume estimation technique with the greatest diagnostic value with respect to perinatal outcome in the postdate pregnancy., Methods: One hundred ninety-eight women who were at least 40 weeks' gestation based on ultrasound confirmation or establishment of dates were evaluated twice weekly with nonstress tests (NSTs) and AF volume estimation. Various indices of AF volume were measured and correlated with perinatal outcome. Receiver operating characteristic curves were used to determine optimal cutoff values., Results: There was a significantly larger maximal vertical pocket in those pregnancies with a normal perinatal outcome than in those with abnormal outcome (4.2 +/- 1.4 versus 3.2 +/- 2.0 cm; P = .02). A statistically significant difference was also seen with the AF index (10.0 +/- 4.5 versus 7.5 +/- 5.0 cm; P = .01). Analysis revealed that the optimal cutoff for identifying clinically significant oligohydramnios was a largest vertical pocket less than 2.7 cm, with an adjusted odds ratio for abnormal perinatal outcome of 7.11 (95% confidence interval [CI] 2.79-18.16). Its sensitivity of 50.0% and specificity of 87.9% were superior to the diagnostic value of the AF index of 5 cm, which had a sensitivity of 29.2% and specificity of 89.1%., Conclusion: A largest vertical pocket threshold of 2.7 cm had the greatest diagnostic value for identifying the postdate pregnancy at risk for abnormal perinatal outcome, surpassing the AF index and the 2-cm largest vertical pocket rule.

One hundred forty-two gravid women at term were followed prospectively by a non-stress test, estimation of amniotic fluid volume and Doppler velocimetry of the umbilical and uterine arteries. Adverse perinatal outcome was detected in 12 women (8.5%). Abnormal antepartum tests were detected in 26 women (17%). Seven women had an abnormally elevated resistance index (RI) in the umbilical artery; but only two had an abnormal outcome. Seven women had an abnormally elevated RI in the uterine artery, but only two had abnormal outcome. Three out of 11 women with oligohydramnion had abnormal perinatal outcome. Only one out of seven women with an abnormal non-stress test had abnormal perinatal outcome. In six women, more than one antepartum test was abnormal. The various surveillance methods demonstrated a low sensitivity (the highest was obtained by estimating amniotic fluid volume: 25%) and a low positive predictive value (the highest obtained by measuring the resistance index in either the umbilical or the uterine arteries: 28.6%). By considering any abnormal test as a positive test result for a given patient, a substantial improvement in sensitivity (66.7%) and positive predictive value (33.3%) are obtained. Doppler velocimetry adds very little in itself to the follow-up of patients with post-term gestations. However, when combined with additional antepartum tests, it may increase our ability to predict the compromised fetus in this condition.

Ultrasound examination has become an indispensable tool in antenatal care. In cases with intrauterine growth retardation, post-term pregnancy and when deciding elective delivery, knowledge about gestational age is essential. However, criticism has been raised against its routine use to determine gestational age. Ultrasound is subject to a certain degree of variation, as is determination of gestational age on the basis of the last menstrual period. Variation is less by ultrasound, which therefore reduces the number of "post-term" pregnancies. The consequences of post-term pregnancy are discussed.

Eight hundred and nineteen patients were evaluated at greater than or equal to 280 days' gestation. All patients underwent nonstress test (NST) and breast stimulation to induce contraction stress test (CST), except where contraindicated. If CST was nonqualifying (less than three contractions per ten minutes), Pitocin (oxytocin) was used to complete the CST if there was a nonreactive NST. Delivery was instituted for any abnormal CST, even with a reactive NST, based on the last test within seven days of delivery. There were 747 reactive NST and 72 nonreactive NST. Breast stimulation for CST was done in 655 instances--315 (48 per cent) had nonqualifying CST and 340 (52 per cent) had qualifying CST. There was an increased incidence of induction in the nonqualifying CST group and abnormal CST group. There were no statistically significant differences in perinatal outcomes in the group with reactive NST, irrespective of the CST result. There were no antepartum fetal deaths.

To assess the correlation between Doppler velocimetry and perinatal outcome in the postdates pregnancy, 75 women who were at least 41 weeks' gestation were evaluated twice weekly until delivery. Evaluation included Doppler velocimetry of the umbilical and uterine-arcuate arteries, as well as nonstress testing and amniotic fluid volume estimation. The mean umbilical artery systolic-diastolic ratio (S/D) was significantly higher in the pregnancies with subsequent abnormal perinatal outcomes than in those with normal outcomes (2.42 versus 2.19; P = .03). Using a receiver operating characteristic curve, an abnormal umbilical artery S/D was defined as 2.40 or greater. Using this value, sensitivity was 57.1% and specificity was 77.8%. Our study suggests that an umbilical artery S/D of 2.40, rather than the more traditionally accepted cutoff of 3.0, may be a useful threshold to identify those postdates pregnancies at high risk for abnormal perinatal outcome.

120 pregnant women between the 26th and 42nd week of gestation have been examined using simple Doppler-units with pulsed- or continuous-wave technique and duplex Doppler-units (combined B-mode and pulsed-wave Doppler). The umbilical and uterine arteries were measured with both units in a semi-recumbent position at the same time by the same examiner. Only ideal flow profiles were taken to calculate the S/D-ratio. Our results were correlated to the fetal outcome, to all cases of pre-eclampsia and to all cases of intra-uterine growth retardation. Except in one of these cases we got the majority of pathological results using simple Doppler-units. Only in pre-eclampsia the duplex Doppler-units had the majority of pathological results. Even in normal fetal outcome the majority of simple Doppler-unit results are pathological. This finding is due to the impossibility to localize the vessel exactly using simple Doppler-units. Sensitivity is higher in simple Doppler-techniques (74.3% to 52.9%), specificity is higher in duplex Doppler-technique (77.9% to 52.6%).

This study examines the efficiency of Doppler flow velocity waveform analysis in the evaluation of the postdate pregnancy. Seventy women whose pregnancies were at or beyond 41 weeks' gestation were assessed by calculating the systolic/diastolic ratios from umbilical and uteroplacental arteries. Waveform ratios from pregnancies associated with fetal compromise and abnormal neonatal outcome were similar to those from pregnancies in which the outcome was normal. These findings indicate that the pathophysiology of placental insufficiency in postdate pregnancies differs from that observed in cases of fetal growth retardation at earlier gestational ages. Doppler flow velocity waveform analysis is unlikely to be of benefit in the routine assessment of the postdate pregnancy.