Doppler ultrasound of the uterine artery in the prediction of severe complications during low-risk pregnancies

AIM

The aim of this prospective study was to assess the role of uterine artery colour Doppler waveform analysis in the prediction of adverse pregnancy outcome such as preeclampsia, intrauterine growth retardation, placental abruption or a combination of outcome parameters.

METHODS

Various uterine artery Doppler ultrasound parameters (RI>0.58, RI>0.7 and unilateral or bilateral notching) were tested. A second objective was to compare the predictive power of uterine artery Doppler ultrasound at 19-22 gestational weeks and 23-26 weeks' gestation for an adverse pregnancy outcome.

RESULTS

The mean time of delivery was 39+0 weeks of gestation. Eight newborns (2%) were delivered before 34 weeks of gestation. The mean birth weight was 3,240 g. Dystrophic fetuses (<10% percentile) were registered in 35 cases (10%). In 31 of the 346 women (9%) a cesarean section was performed because of abnormal fetal heart recording. Preeclampsia was diagnosed in 17 cases (5%). In 5 cases (1.4%) a placental abruption and 2 (0.6%) intrauterine fetal deaths were diagnosed. The sensitivity of notching for the prediction of preeclampsia was 88% and for the prediction of a severe pregnancy complication (preeclampsia and/or intrauterine growth retardation and/or intrauterine fetal death and/or placental abruption) at any gestational age was 62% with relative risks of 9.7 and 2.2, respectively. The sensitivity of notching for severe pregnancy complications requiring delivery before 34 weeks was 64% with a relative risk of 2.4. The sensitivity of notching in the uterine arteries for developing an IUGR was 56% with a relative risk of 1.7.

CONCLUSION

The predictive value of uterine artery Doppler for adverse pregnancy outcome in a low-risk population is of limited diagnostic value. Performing uterine artery Doppler studies at 23-26 weeks' gestation instead of 19-22 weeks' gestation increases the predictive value for adverse pregnancy outcomes.

The value of uterine artery Doppler ultrasound in the prediction of severe complications in a risk population

AIM

The aim of this prospective study was to assess the role of uterine artery color Doppler waveform analysis in the prediction of adverse pregnancy outcome such as preeclampsia, intrauterine growth retardation, placental abruption or a combination of outcome parameters in risk pregnancies (n=52).

METHODS

Various uterine artery Doppler ultrasound parameters (resistance index (RI)>0.58, RI>0.7 and uni/bilateral or bilateral notching) were tested. The mean time of delivery was 37+1 weeks' gestation. Six newborns (12%) were delivered before 34 weeks of gestation. The mean birth weight was 2,910 g. Dystrophic fetuses (<10% percentile) were registered in 7 cases (13%). In 11 of the 52 women (21%) a cesarean section was performed because of abnormal fetal heart recording.

RESULTS

Preeclampsia was diagnosed in 4 cases (8%). In 4 cases (8%) an intrauterine fetal death was diagnosed. Placental abruption did not occur. The sensitivity of notching for the prediction of preeclampsia and for the prediction of a severe pregnancy complication was 75 and 69% with relative risks of 2.7 and 2.0. The sensitivity of notching in the uterine arteries for developing an intrauterine growth retardation (IUGR) was 71% with a relative risk of 2.2. The sensitivity of RI>0.58 in the uterine arteries for developing an IUGR was 67% with a relative risk of 5.4. The sensitivity of RI>0.58 for the prediction of preeclampsia, of intrauterine death and for the prediction of a severe pregnancy complication was 50, 75 and 80% with relative risks of 2.7, 8.1 and 10.9 respectively.

CONCLUSION

The results of this study suggest that Doppler ultrasound of the uterine artery in the second trimester of gestation is a useful method to predict abnormal outcomes in risk pregnancies, with high negative predictive values.

Ultrasound estimates of gestational age among perinatally demised: a population-based study

BACKGROUND

Correct estimation of gestational age may improve the quality of obstetric care. We hypothesize that significant differences between traditional and alternative estimates by ultrasound are evident among perinatal deaths.

METHODS

Population-based case series with data linkage between autopsy records and The Medical Birth Registry of Norway, including perinatally demised singletons who were examined by autopsy and post-mortem radiography, having antenatal estimates of gestational age both by the calendar method, as calculated from the first day of the last menstrual period preceding the pregnancy (GAlmp), and by mid-second-trimester ultrasound (GAus), N = 380. The main outcome measure was the distribution of GAlmp and GAus within weight strata.

RESULTS

Mean GAus was 1 week less than mean GAlmp (t-test, p < 0.001). The degree of apparent growth restriction manifest after death, as expressed by both birthweight and by post-mortem radiographic measurements, was fairly well correlated with the degree of downward adjustment of age by ultrasound in the early second trimester (Pearson's correlation, r = - 0.599, p < 0.001). The degree of discrepancy between the ultrasound and the calendar methods was associated both with placenta findings (Kruskal-Wallis test, chi2 = 20.95, p = 0.007) and with the main cause of death (Kruskal-Wallis test, chi2 = 27.65, p = 0.004).

CONCLUSION

Among infants who died perinatally, gestational age seemed to be systematically downward adjusted by mid-second-trimester screening ultrasound, particularly among those who were the most growth retarded at the time of death.

Abnormal Umbilical Cord Doppler Sonograms May Predict Impending Demise in Fetuses with Sacrococcygeal Teratoma

OBJECTIVE

To identify factors predictive of fetal demise in fetuses with sacrococcygeal teratoma (SCT).

METHOD

The recent management of monochorionic twins discordant for a large SCT and a singleton with a large SCT was reviewed.

RESULTS

Serial fetal echocardiography and ultrasonography with Doppler flow measurements documented rapid growth of the SCT in both cases with a relatively modest increase in combined cardiac output. No placentomegaly or hydrops was observed at any time. In both fetuses with SCT, evolution of abnormal umbilical artery waveforms was observed with the ultimate development of reversed end-diastolic umbilical arterial flow that was followed by sudden fetal demise.

CONCLUSION

Death in these 2 fetuses with large SCTs in the absence of placentomegaly/hydrops or hemodynamic changes suggestive of evolving high-output failure suggests a previously unrecognized mechanism of death in fetuses with large rapidly growing SCTs. In these cases, fetal demise may only be heralded by abnormal umbilical artery waveforms that progress to the premorbid observation of reversed diastolic umbilical artery blood flow. Umbilical artery waveform analysis should be closely monitored with other hemodynamic parameters in fetuses with large SCTs. In such fetuses, depending on the gestational age, abnormalities in umbilical artery waveform should be considered indications for early delivery or in utero intervention to prevent fetal demise.

Abnormal Umbilical Cord Dopplers May Predict Impending Demise in Fetuses with Sacrococcygeal Teratoma

OBJECTIVE

To identify factors predictive of fetal demise in fetuses with sacrococcygeal teratoma (SCT).

METHOD

The recent management of monochorionic twins discordant for a large SCT and a singleton with a large SCT were reviewed.

RESULTS

Serial fetal echocardiography and ultrasonography with Doppler flow measurements documented rapid growth of the SCT in both cases with a relatively modest increase in combined cardiac output. No placentomegaly or hydrops was observed at any time. In both fetuses with SCT, evolution of abnormal umbilical artery waveforms was observed with the ultimate development of reversed end-diastolic umbilical arterial flow that was followed by sudden fetal demise.

CONCLUSION

Death in these 2 fetuses with large SCTs in the absence of placentomegaly/hydrops or hemodynamic changes suggestive of evolving high-output failure suggests a previously unrecognized mechanism of death in fetuses with large rapidly growing SCTs. In these cases, fetal demise may only be heralded by abnormal umbilical artery waveforms that progress to the premorbid observation of reversed diastolic umbilical artery blood flow. Umbilical artery waveform analysis should be closely monitored with other hemodynamic parameters in fetuses with large SCTs. In such fetuses, depending on the gestational age, abnormalities in umbilical artery waveform should be considered indications for early delivery or in utero intervention to prevent fetal demise.

Prognostic factors associated with antenatal subchorionic echolucencies

OBJECTIVE

This study was undertaken to determine prognostic factors in pregnancies with a subchorionic echolucency.

STUDY DESIGN

One hundred twenty-nine pregnancies with a subchorionic echolucency detected by ultrasound in our unit were identified. Ultrasound reports were reviewed for subchorionic echolucency location, size, gestational age, amniotic fluid volume, and fetal abnormalities. Adverse outcomes evaluated were pregnancy loss before 24 or 37 weeks (PTD) and intrauterine growth restriction. Medical records were reviewed for antenatal complications and neonatal outcomes.

RESULTS

There were 7 (5.4%) pregnancy losses before 24 weeks and 24 (18.6%) pregnancies complicated by PTD. Of the 122 pregnancies reaching viability, those complicated by antepartum bleeding were more likely to deliver prematurely than those without bleeding, (26.6% vs 7.0%, P=.009). Maximum area of subchorionic echolucency, gestational age at subchorionic echolucency detection, amniocentesis, maternal age, and parity were not associated with PTD.

CONCLUSION

Patients with subchorionic echolucency appear to have a high incidence of PTD. Bleeding appears to be a reliable prognostic indicator.

PRENATAL SONOGRAPHIC DIAGNOSIS OF FETAL DEATH AND HYDRANENCEPHALY IN TWO CHIHUAHUA FETUSES

Hydranencephaly and fetal death was diagnosed in two of three fetuses during the abdominal sonographic examination of a 2.5-year-old, intact female Chihuahua that had clinical signs of dystocia 63 days after mating. A cesarean section was performed and one live normal puppy was present. Two dead puppies, each with a markedly enlarged and fluid filled skull were removed.

Qualitative venous Doppler waveform analysis improves prediction of critical perinatal outcomes in premature growth-restricted fetuses

BACKGROUND

Our aim was to test the hypothesis that qualitative ductus venosus and umbilical venous Doppler analysis improves prediction of critical perinatal outcomes in preterm growth-restricted fetuses with abnormal placental function.

METHODS

Patients with suspected intrauterine growth restriction (IUGR) underwent uniform fetal assessment including umbilical artery (UA), ductus venosus (DV) and umbilical vein (UV) Doppler. Absent or reversed UA end-diastolic velocity (UA-AREDV), absence or reversal of atrial systolic blood flow velocity in the DV (DV-RAV) and pulsatile flow in the umbilical vein (P-UV) were examined for their efficacy to predict critical outcomes (stillbirth, neonatal death, perinatal death, acidemia and birth asphyxia) before 37 weeks' gestation.

RESULTS

Seventeen (7.6%) stillbirths and 16 (7.1%) neonatal deaths were observed among 224 IUGR fetuses. Forty-one neonates were acidemic (19.8%) and seven (3.1%) had birth asphyxia. Logistic regression showed that UA-AREDV had the strongest association with perinatal mortality (R(2) = 0.49, P < 0.001), stillbirth (R(2) = 0.48, P < 0.001) and acidemia (R(2) = 0.22, P = 0.002) while neonatal death was most strongly related to DV-RAV and P-UV (R(2) = 0.33, P = 0.007). UA waveform analysis offered the highest sensitivity and negative predictive value and DV-RAV and P-UV had the best specificity and positive predictive values for outcome prediction. Overall, DV-RAV or P-UV offered the best prediction of acidemia and neonatal and perinatal death irrespective of the UA waveform. In fetuses with UA-AREDV, prediction of asphyxia and stillbirth was significantly enhanced by venous Doppler.

CONCLUSION

Prediction of critical perinatal outcomes is improved when venous and umbilical artery qualitative waveform analysis is combined. The incorporation of venous Doppler into fetal surveillance is therefore strongly suggested for all preterm IUGR fetuses.

Single umbilical artery and umbilical cord torsion leading to fetal death. A case report

BACKGROUND

Intrauterine fetal death is a complication that cannot often be predicted by standard obstetric management. Cord accident may be responsible for about 5% of cases. Umbilical cord torsion is an extremely rare cause of intrauterine fetal death.

CASE

An 18-year-old, nulliparous woman presented with a complaint of decreased fetal movement at 38 weeks' gestation. Intrauterine fetal death was diagnosed on ultrasound. The pathologic examination revealed umbilical cord torsion and confirmed a single umbilical artery that was diagnosed on ultrasound.

CONCLUSION

Umbilical cord torsion that leads to intrauterine fetal death is extremely rare. A pregnancy with a single umbilical artery may need fetal monitoring during the third trimester.

The role of Doppler studies in predicting individual intrauterine fetal demise after laser therapy for twin-twin transfusion syndrome

OBJECTIVE

To investigate the role of Doppler studies in predicting individual fetal demise in patients scheduled for selective laser photocoagulation of communicating vessels (SLPCV) for twin-twin transfusion syndrome (TTTS).

METHODS

Doppler studies of the umbilical artery, umbilical vein, ductus venosus, tricuspid valve regurgitation and middle cerebral artery were performed in the donor and recipient twins before and 24 hours after SLPCV. Results were analyzed cross-sectionally and longitudinally. As multiple comparisons were made, an a priori alpha rejection was set at P < 0.001.

RESULTS

One hundred and ten consecutive patients were available for analysis. Overall fetal survival was 68.6% (151/220) with at least one survivor in 88.2% (97/110) of cases. Absent or reversed end-diastolic velocity in the umbilical artery of the donor twin was the only preoperative Doppler result predictive of intrauterine fetal demise (IUFD) (10/15, 66.7%, P < 0.001). Postoperatively, reversed flow during atrial contraction in the ductus venosus of the donor twin showed a trend towards prediction of IUFD of this fetus (4/5, 80%, P = 0.007). No other Doppler studies, including the longitudinal analyses, were predictive of IUFD.

CONCLUSIONS

Our data suggest that preoperative absent or reversed end-diastolic velocity in the umbilical artery may be useful in predicting individual fetal demise of the donor twin in TTTS patients scheduled for SLPCV. This may reflect the role of decreased individual placental mass that may be associated with some donor twins. The inability of other Doppler studies to predict individual IUFD may be explained preoperatively by the effect of the interfetal vascular connections on the individual Doppler signals and postoperatively by the effect of surgery or the timing of the assessment. Our findings may be important in patient counseling, in furthering understanding of the disease, and perhaps in improving surgical technique.

Complications arising in twin pregnancy: findings of prenatal ultrasonography

Multifetal gestations are high-risk pregnancies involving higher perinatal morbidity and mortality, and are subject to unique complications including twin oligohydramnios-polyhydramnios sequence, twin-to-twin transfusion syndrome, acardiac twins, conjoined twins, co-twin demise, and heterotopic pregnancies. The purpose of this study is to describe the prenatal ultrasonographic and pathologic findings of these complications.

Ossification sequence in infants who die during the perinatal period: population-based references

PURPOSE

To determine population-based references for the relationships between the presence of ossification centers and gestational age and skeletal length measurements among infants who die during the perinatal period, as well as to evaluate the possible influence of intrauterine growth restriction on ossification stage.

MATERIALS AND METHODS

During an 11-year period, nearly all infants who died perinatally in a well-defined geographic area routinely underwent radiography with a standardized technique. The presence of visible secondary ossification centers in the singletons (n = 495) was evaluated. Cluster analysis was used to identify stages of ossification; a sequential appearance of secondary ossification centers was assumed. Comparisons were made with Wilks lambda between male and female infants and between infants who were presumed to have growth restriction and those who were not. Reference ranges for the presence of ossification centers were calculated for interquartile ranges of femur length and gestational age.

RESULTS

Eight clusters of ossification defining different stages of ossification of the pelvis, hindfeet, and knees were identified. The sequential clusters outlined well-defined intervals of femur length and gestational age. Bone lengths, birth weight, and gestational age within ossification clusters did not differ between the sexes (Wilks lambda = 0.989, P =.532) or according to whether growth restriction was presumed to exist (Wilks lambda = 0.958, P =.481).

CONCLUSION

The reference diagrams calculated with this method indicate relationships between ossification sequence and both gestational age and skeletal length measurements.

Embolization for advanced abdominal pregnancy with a retained placenta. A case report

BACKGROUND

Abdominal pregnancy is not encountered commonly, and management of the placenta is controversial.

CASE

A 33-year-old woman presented with an abdominal pregnancy at 33 weeks' gestation with fetal death. The placental vasculature was embolized preoperatively. Following operative delivery. of the fetus, the placenta was left in situ in efforts to preserve fertility given its implantation on the reproductive organs. The patient suffered prolonged postoperative ileus but otherwise did well. Placental function ceased after two months.

CONCLUSION

Placental vasculature embolization is a management option for a retained placenta associated with abdominal pregnancy.

Venous Doppler velocimetry in the surveillance of severely compromised fetuses

OBJECTIVE

To investigate whether venous Doppler velocimetric signs of cardiac decompensation might predict fetal demise in severely compromised fetuses.

MATERIAL AND METHODS

This was a prospective study involving 154 growth-restricted fetuses, 37 of which were found to have reversed flow in the umbilical artery (BFC III). Doppler velocimetry of the right hepatic vein and ductus venosus were investigated serially and the presence of umbilical venous pulsations also registered. Only the final examination prior to birth or fetal demise was accepted for analysis and related to obstetric outcome defined as gestational age at birth, birth weight and perinatal mortality. In cases of BFC III the venous velocimetry of 15 nonsurviving fetuses was compared to that of the 22 survivors.

RESULTS

There was a significant correlation between venous blood velocity and placental vascular resistance. In the right hepatic vein there was a significant decrease in peak systolic and end-systolic velocities and an increase of maximum velocity during atrial contraction and pulsatility (P < 0.05). A decrease of all velocities and increase of pulsatility were noted in the ductus venosus (P < 0.05). A reversed flow in the ductus venosus was found in 9/37 fetuses and double umbilical venous pulsations in 16/37 fetuses. However, the hepatic vein seemed to be a better predictor of impending mortality than the ductus venosus. Changes in diastolic venous blood velocity and a double pulsation in the umbilical vein were closely related to perinatal mortality, although these parameters did not provide a useful threshold to optimize the timing of delivery.

CONCLUSION

Diastolic venous velocimetry changes significantly in severely compromised fetuses. These changes might be of great clinical value in deciding on the timing of delivery to minimize damage to the fetus and newborn.

Skeletal measurements among infants who die during the perinatal period: new population-based reference

BACKGROUND

Reference data for roentgen skeletal measurements among infants who die during the perinatal period is not available, although it might prove helpful in the study of pre-autopsy radiographs.

OBJECTIVE

Our aim was to define new population-based reference data for skeletal measurements among infants who die during the perinatal period.

MATERIALS AND METHODS

We routinely took standardised pre-autopsy radiographs of aborted and stillborn fetuses from 16 weeks gestational age to 7 days after delivery during a period of 11 years in our hospital. The data presented here represents nearly all perinatal deaths in a well-defined geographical area during the study period. We calculated detailed plots of estimated 10th-90th centiles and quartiles of different skeletal measurements by gestational age at death.

RESULTS

High correlations were seen between birth weight and the different skeletal measurements, including cranial width ( r>0.9, P<0.001). We were not able to identify any asymmetrical pattern of skeletal growth. Reference plots for femoral, tibial, humeral, radial and lumbar spine lengths, and for pelvic width are presented.

CONCLUSIONS

We suggest that the current population-based reference data might be beneficial, and that skeletal radiographic measurements might contribute substantially in the assessment of fetal growth stage and in detection of skeletal abnormalities in infants who die during the perinatal period.

Medical management of late intrauterine death using a combination of mifepristone and misoprostol

OBJECTIVE

To assess the efficacy and safety of mifepristone in combination with misoprostol in the management of late fetal death.

DESIGN

Observational study.

SETTING

Aberdeen Maternity Hospital, Aberdeen.

METHODS

A consecutive series of 96 women with intrauterine death after 24 weeks of gestation were studied. Each woman received a single dose of 200 mg mifepristone orally, following which a 24-48 hour interval was recommended before administration of misoprostol. For gestations of 24-34 weeks, 200 microg of intravaginal misoprostol was administered, followed by four oral doses of 200 microg at three hourly intervals. Gestations over 34 weeks were given a similar regimen but a reduced dose of 100 microg misoprostol.

RESULTS

The average induction to delivery interval was 8.5 hours. Ninety-five women (98.9%) were delivered within 72 hours of administration of first dose of misoprostol, with 66.7%, 87.5%, 92.7% and 95.8% women delivering within 12, 24, 36 and 48 hours, respectively. No significant correlation was found between mean induction to delivery interval and maternal age, parity, Bishop's score, birthweight and mifepristone/ misoprostol interval. The induction to delivery interval was shorter with increasing gestation (P = 0.04). Mild side effects were noted in eight (8.3%) women. Three (3.1%) women had treatment for presumed or proven pelvic sepsis. No cases of uterine tachysystole, haemorrhage or coagulopathy were recorded.

CONCLUSION

The combination of mifepristone and misoprostol for induction of labour following late fetal death is an effective and safe regimen. The induction to delivery interval with this regimen appears shorter than studies using mifepristone or misoprostol.

Frequency and occurrence of late-gestation losses from cattle cloned embryos

Nuclear transfer from somatic cells still has limited efficiency in terms of live calves born due to high fetal loss after transfer. In this study, we addressed the type of donor cells used for cloning in in vivo development. We used a combination of repeated ultrasonography and maternal pregnancy serum protein (PSP60) assays to monitor the evolution of pregnancy after somatic cloning in order to detect the occurrence of late-gestation losses and their frequency, compared with embryo cloning or in vitro fertilization (IVF). Incidence of loss between Day 90 of gestation and calving was 43.7% for adult somatic clones and 33.3% for fetal somatic clones, compared with 4.3% after embryo cloning and 0% in the control IVF group. Using PSP60 levels in maternal blood as a criterion for placental function, we observed that after somatic cloning, recipients that lost their pregnancy before Day 100 showed significantly higher PSP60 levels by Day 50 than those that maintained pregnancy (7.77 +/- 3.3 ng/ml vs. 2.45 +/- 0.27 ng/ml for normal pregnancies, P < 0.05). At later stages of gestation, between 4 mo and calving, mean PSP60 concentrations were significantly increased in pathologic pregnancy after somatic cloning compared with other groups (P < 0.05 by Day 150, P < 0.001 by Day 180, and P < 0.01 by Day 210). In those situations, and confirmed by ultrasonographic measurements, recipients developed severe hydroallantois together with larger placentome size. Our findings suggest that assessing placental development with PSP60 and ultrasonography will lead to better care of recipient animals in bovine somatic cloning.

[Clinical features of missed abortion]

RATIONALE

There is no general agreement concerning the definition of missed abortion which remains one of the most commonly encountered pregnancy complication of an extremely variable clinical picture.

AIM OF THIS STUDY

The analysis of the clinical symptoms of missed abortion.

SETTING

Academic Medical Center.

MATERIALS AND METHODS

Consecutive 50 women with non-viable pregnancy from 7 to 22 weeks, diagnosed by clinical examination, ultrasonography and serum beta-HCG evaluation were studied.

RESULTS

In 92% of the missed abortion cases a vaginal spotting was observed before the diagnosis was established. The average period of the estimated retention of the products of conception was 2.8 weeks. In only one patients this period exceeded 8 weeks. The reverse correlation was established between the gravidity of a patient and the period of asymptomatic retention of the non-viable conception products in uterus. The obtained results confirm that the onset of vaginal bleeding does not reflect the moment of embryonal/fetal death.