Omphalocele: comparison of outcome following prenatal or postnatal diagnosis.

OBJECTIVES: To assess the impact of prenatal compared with postnatal diagnosis on outcome for liveborn infants with an isolated or with a non-isolated omphalocele. METHODS: This was a retrospective analysis of 101 prenatally and 45 postnatally diagnosed cases of omphalocele. Cases were collected from the ultrasound database of the Division of Obstetrics and Prenatal Medicine and the patient database of the Department of Pediatric Surgery. RESULTS: Following confirmation at delivery or autopsy, prenatally diagnosed omphaloceles included 21 isolated cases, 44 non-isolated cases with a normal karyotype and 36 non-isolated cases with an abnormal karyotype. Of the prenatally diagnosed apparently isolated cases (n = 31), 12 (39%; 95% CI, 22-58%) revealed associated anomalies after delivery. Liveborn infants with an isolated omphalocele had significantly worse short-term morbidity following prenatal diagnosis (n = 14) compared with diagnosis at birth (n = 29), having a lower gestational age at delivery, lower Apgar scores, longer duration of ventilation and parenteral nutrition, more readmissions and a longer hospital stay. The prenatally diagnosed subset contained more infants with a giant omphalocele (9/14 vs. 3/29, P = 0.001) and liver herniation (8/14 vs. 6/29, P = 0.02). The outcome of liveborn infants with a non-isolated omphalocele diagnosed prenatally (n = 17) was not different from that of those diagnosed at birth (n = 16), except for a greater need for ventilation and parenteral nutrition in the prenatal subset. CONCLUSION: When counseling patients with a prenatal diagnosis of isolated omphalocele, it is important to remember that over one third could turn out to have associated anomalies. Liveborn infants with an isolated omphalocele detected prenatally have worse short-term morbidity than do cases detected at birth. Those with non-isolated omphaloceles detected prenatally have an increased need for ventilation and parenteral nutrition compared with those detected at birth.

Isolated or non-isolated duodenal obstruction: perinatal outcome following prenatal or postnatal diagnosis.

OBJECTIVES: To determine whether the pre- or postnatal diagnosis of either isolated or non-isolated duodenal obstruction (DO) is associated with different outcomes. METHODS: A single-center retrospective analysis was carried out of 91 cases diagnosed with a DO between January 1991 and June 2003. Data on the diagnosis, treatment and outcomes of the cases were gathered, and differences between the groups were analyzed. RESULTS: Twenty-eight cases of DO were diagnosed before and 63 after birth. Of 15 presumed isolated cases in the prenatally diagnosed group, four revealed associated or chromosomal anomalies after birth. The types of obstruction present were significantly different between the prenatally (n = 11) and postnatally (n = 27) detected subsets of isolated DO. The prenatally detected subset displayed a lower median gestational age at delivery, lower median birth weight and a higher prematurity rate (8/11 vs. 8/27). The diagnosis of DO occurred significantly later in the postnatally detected subset than the postnatal confirmation of the diagnosis in the prenatally detected cases. In the non-isolated cases of DO, no difference was found in the type of chromosomal or associated anomaly or the type of obstruction between the prenatally detected (n = 17) and postnatally detected subsets (n = 36). Trisomy 21 was present in 7/17 (41%) vs. 22/36 (61%) cases, respectively. Two terminations and three intrauterine deaths occurred in the prenatal non-isolated subset. The liveborn infants from the prenatally detected non-isolated subset (n = 12) showed a significantly higher prematurity rate (9/12 vs.14/36), lower median birth weight and earlier confirmation of diagnosis after delivery. After surgery, outcome was similar between both subsets of isolated and non-isolated DO. All the infants with an isolated DO survived. Neonatal death occurred in three prenatally and five postnatally diagnosed cases with non-isolated DO. CONCLUSIONS: The outcome of prenatally and postnatally diagnosed DO is not essentially different despite more prematurity and a lower birth weight in the former. Of the prenatally detected cases of DO assumed to be isolated, 25% revealed additional chromosomal or associated anomalies after delivery, which influenced outcome.

Blood pressure estimation in the human fetal descending aorta.

OBJECTIVES: The objectives of this study were to estimate fetal blood pressure non-invasively from two-dimensional color Doppler-derived aortic blood flow and diameter waveforms, and to compare the results with invasively derived human fetal blood pressures available from the literature. METHODS: Aortic pressures were calculated from digitally recorded color Doppler cineloops of the fetal descending aorta by applying the Womersley model in combination with the two-element Windkessel model, assuming constant pulse wave velocity during the second half of pregnancy. The results were compared with invasively derived human fetal blood pressures obtained from the literature. RESULTS: In 21 normal pregnancies the estimated mean aortic pressure regression line increased linearly from 28 mmHg at 20 weeks of gestation to 45 mmHg at 40 weeks of gestation. The pulse pressure based on the regression line increased linearly from 21 mmHg at 20 weeks of gestation to 29 mmHg at 40 weeks of gestation. The aortic compliance exhibited a log linear relationship with the gestational age and a statistically significant eightfold increase was observed between 20 and 40 weeks. The aortic downstream peripheral resistance exhibited an exponentially decaying relationship across the same gestational age range. Non-invasively derived aortic systolic and diastolic aortic pressures were comparable with previously reported invasively derived systolic and diastolic umbilical arterial pressures; however, the mean pressures differed significantly from those reported in the umbilical artery in a separate study. The aortic systolic pressures calculated in this study were significantly higher than invasively derived left ventricular systolic pressures that have been previously reported in the literature. CONCLUSIONS: This study demonstrates the feasibility of estimating arterial blood pressure in the human fetus. The method described is of potential use in assessing fetal blood pressure non-invasively, particularly for studying relative changes with time.

Systolic and diastolic ventricular function in the normal and extra-embryonic venous clipped chicken embryo of stage 24: a pressure-volume loop assessment.

OBJECTIVES: Fluid mechanical forces affect cardiac development. In the chicken embryo, permanent obstruction of the right lateral vitelline vein by clipping reduces the mechanical load on the embryonic myocardium, which has been shown to induce a spectrum of outflow tract anomalies. Insight into the effects of this intervention on the mechanical function of the developing myocardium could contribute to a better understanding of the relationship between hemodynamics and cardiac morphogenesis. We aimed to explore the effects of clipping on intrinsic systolic and diastolic ventricular function at stage 24 in the chicken embryo METHODS: Cardiac pressure-volume relationships enable load-independent quantification of intrinsic ventricular systolic and diastolic properties. We determined ventricular function by pressure-volume loop analysis of in-ovo stage-24 chicken embryos (n = 15) 2 days after venous obstruction at 2.5 days of incubation (stage 17, venous clipped embryos). Control embryos (n = 15) were used for comparison. RESULTS: End-systolic volume was significantly higher in clipped embryos (0.36 +/- 0.02 microL vs. 0.29 +/- 0.02 microL, P = 0.002). End-systolic and end-diastolic pressure were also increased compared with control animals (2.93 +/- 0.07 mmHg vs. 2.70 +/- 0.08 mmHg, P = 0.036 and 1.15 +/- 0.06 mmHg vs. 0.82 +/- 0.05 mmHg, P < 0.001, respectively). No significant differences were demonstrated for other baseline hemodynamic parameters. Analysis of pressure-volume relationships showed a significantly lower end-systolic elastance in the clipped embryos (slope of end-systolic pressure-volume relationship: 2.91 +/- 0.24 mmHg/microL vs. 7.53 +/- 0.66 mmHg/microL, P < 0.005) indicating reduced contractility. Diastolic stiffness was significantly increased in the clipped embryos (slope of end-diastolic pressure-volume relationship: 1.54 +/- 0.21 vs. 0.60 +/- 0.08, P < 0.005), indicating reduced compliance. CONCLUSION: Venous obstruction apparently interferes with normal myocardial development, resulting in impaired intrinsic systolic and diastolic ventricular function. These changes in ventricular function may precede morphological derangements observed in later developmental stages.

Three-dimensional sonography of prenatal skull base development.

OBJECTIVE: To explore longitudinally the development of the fetal skull base using three-dimensional (3D) sonography. METHODS: Serial 3D sonographic measurements of anterior skull base length, posterior cranial fossa length and skull base angle were made in 126 normal singleton pregnancies at 18-34 weeks of gestation. In a sub-study of 22 pregnancies, intraobserver variability was determined. Regression analysis for repeated measurements was performed by means of the random coefficients model. Results from an earlier publication on brain volume were extended to the total patient cohort. RESULTS: Measurements were technically successful in 69-94% of cases. The coefficient of variation for differences between repeated tests within women was 3.5-7.6% and between repeated analyses of the same recorded volume it was 3.0-5.1%. A statistically significant gestational age-related increase was established for both the anterior skull base length and the posterior cranial fossa length and the skull base angle showed a small but significant flexion of about 6 degrees . A higher increment in posterior cranial fossa length relative to anterior skull base angle was established. A significant quadratic relationship could be established for both anterior skull base length (P < 0.0001) and posterior cranial fossa length (P < 0.0001) but not for skull base angle, relative to brain volume. CONCLUSION: The reproducibility was acceptable for all fetal skull base measurements. The more pronounced growth in posterior cranial fossa length relative to anterior skull base length is influenced by brain growth. The small flexion of the skull base angle, however, may be caused by other factors. Published by John Wiley & Sons, Ltd.

Craniofacial variability index in utero: a three-dimensional ultrasound study.

OBJECTIVE: This study was undertaken to develop a craniofacial pattern profile analysis by three-dimensional (3D) ultrasound and to introduce a craniofacial variability index (CVI) which can assist in the evaluation of fetal facial anatomy. METHODS: Serial 3D sonographic measurements of 16 different fetal craniofacial parameters were performed at 18-34 weeks of gestation in 126 normal singleton pregnancies. In another six pregnancies complicated by fetal abnormality, a single 3D recording was obtained. The 16 measurements cover various aspects of the facial anatomy, such as width, depth and height. For each parameter, regression analysis was performed to calculate gestational age-specific Z-scores and normal limits for the CVI (the latter quantifies the variability between the 16 Z-scores). RESULTS: The 95th percentile of normal CVI data increased from 1.08 at 18 weeks to 1.27 at 34 weeks of gestation. The CVI was situated above the 95th percentile in three out of six fetuses with abnormalities. In abnormal subjects, 2-8 of 16 parameters showed abnormal values. CONCLUSIONS: Craniofacial pattern profile analysis and the CVI may aid in the evaluation of fetal facial anatomy. They could be a valuable tool in syndrome delineation and for distinguishing between normal and abnormal craniofacial development.

Craniofacial variability index determined by three-dimensional ultrasound in isolated vs. syndromal fetal cleft lip/palate.

OBJECTIVE: This study was undertaken to employ craniofacial pattern profile analysis in fetal facial clefts and to evaluate the craniofacial variability index (CVI) in distinguishing between isolated and syndromal clefts. METHODS: Three-dimensional (3D) sonographic assessment of 16 different fetal craniofacial measurements was performed in each of eight pregnancies complicated by an isolated facial cleft and seven pregnancies with a syndromal cleft. The measurements covered various aspects of facial width, depth and height. Measured values were compared to gestational age-specific normal values for calculation of Z-scores and the CVI. The number of abnormal Z-scores, i.e. < - 2 or > + 2, found among the measured values and the CVI in the group of isolated facial clefts were compared to those in the group with syndromal clefts. RESULTS: The CVI could be calculated in 14 of 15 fetuses (93%). More abnormal Z-scores and a higher mean CVI were found in the group with more severe (bilateral) facial clefts. Most abnormal values were found in the facial width measurements. Syndromal cleft lip/palate was associated with significantly more abnormal Z-scores and a higher mean CVI than isolated cleft lip/palate (P < 0.05). CONCLUSION: Craniofacial variability index may be a valuable tool for distinguishing between isolated and syndromal fetal cleft lip/palate.

Three-dimensional sonographic determination of normal fetal mandibular and maxillary size during the second half of pregnancy.

OBJECTIVE: To explore the various ways of obtaining fetal maxillary and mandibular size with three-dimensional (3D) ultrasound, with a view to developing a tool for identifying minor anomalies in the lower facial region. METHODS: Serial 3D sonographic measurements of the fetal jaws were made in 126 normal singleton pregnancies at 18-34 weeks of gestation for determination of degree of maxillary and mandibular protrusion, maxillary and mandibular corpus lengths, mid- and lower facial depths and maxillary and mandibular curvature. In a sub study the reproducibility of the measurements was evaluated. RESULTS: The coefficient of variation in the reproducibility study varied between 7.1 and 10.5%. For all parameters except maxillary and mandibular protrusion, there was a significant gestational age-related increase. Ratios of maxillary/mandibular protrusion, maxillary/mandibular corpus lengths, mid-/lower facial depths and maxillary/mandibular curvature all showed a significant gestational age-related decrease, with the most distinct decrease in the mid-/lower facial depth ratio. CONCLUSIONS: 3D sonographic measurement of the fetal maxilla and mandible demonstrated an acceptable intraobserver variability for all measurements. The mid-/lower facial depth ratio appears to be most valuable in determining abnormal mandibular development.

Congenital talipes equinovarus: comparison of outcome between a prenatal diagnosis and a diagnosis after delivery.

OBJECTIVES: To establish the impact on outcome of prenatally versus postnatally detected talipes equinovarus (TEV). METHODS: The prenatal group was represented by pregnancies with sonographically detected TEV of which 18 were isolated and 39 were complex. The postnatal group contained 64 infants with an isolated and 10 infants with a complex TEV detected at birth. Treatment consisted of redressement followed by surgical postero-lateral or postero-medial release at the University Paediatric Orthopaedic Centre. The postnatal isolated TEV group underwent redressement treatment at the University Centre (subset A, n = 39) or at a regional general hospital (subset B, n = 25). RESULTS: For isolated TEV, statistically significant difference existed for the surgical procedure (p < 0.001), age at surgery (p < 0.01) and admission time (p < 0.001) between the prenatal and postnatal subset B and between the postnatal subsets A and B. For the complex TEV, no significant difference was found for these variables between the six surviving infants of the prenatal group and the postnatal group. CONCLUSION: Prenatal detection of isolated TEV results in earlier and less complicated postnatal surgery and a shorter admission time, provided treatment is arranged at a paediatric orthopaedic centre. After prenatal detection of a complex TEV, survival is low and determined by associated anomalies.

Comparison between color Doppler cineloop- and conventional spectral Doppler-derived maximum velocity and flow in the umbilical vein.

OBJECTIVE: To compare the umbilical venous flow velocity derived from color Doppler cineloop recordings with that derived from conventional spectral Doppler in normal pregnancies. METHOD: In 18 uncomplicated pregnancies between 19 and 39 weeks' gestation, color Doppler was used to find the maximum velocity in the cross-sectional vessel area of a free-floating loop of the umbilical vein. The maximum velocity was determined using the software tool HDI_Lab (Philips Medical Systems) after tracing the vessel area of interest. Conventional spectral Doppler was then used to determine the maximum velocity with the High-Q machine option. The cross-sectional area of the umbilical vein was determined using B-mode imaging and was subsequently used to determine the umbilical volume flow from both Doppler methods. Assuming a parabolic flow profile in the umbilical vein, the mean velocity is equal to half the maximum velocity. The fetal weight was estimated from fetal biometry using the four-parameter Hadlock formula. RESULTS: Maximum velocity was significantly (P = 0.003) higher with color Doppler cineloop (14.3 +/- 2.5 cm/s) compared with spectral Doppler (12.7 +/- 3.2 cm/s). Therefore, using the same cross-sectional area for both methods, the umbilical blood flow was significantly higher (P = 0.001) with color Doppler cineloop (127.9 +/- 59.0 mL/min) than it was with spectral Doppler (112.8 +/- 54.1 mL/min). The umbilical blood flow expressed as volume flow per kg fetal weight was significantly (P = 0.01) higher with color Doppler cineloop (126.0 +/- 57.0 mL/min/kg) than it was with spectral Doppler (115.0 +/- 53.0 mL/min/kg). CONCLUSIONS: Umbilical venous flow velocity derived from color Doppler cineloops is approximately 10% higher than that derived from spectral Doppler-derived velocity. The reduced angle dependence of the color Doppler cineloop technique and the large sampling area of the cross-sectional vessel should allow better determination of the correct maximum velocity in the umbilical vein.

Wall shear stress and related hemodynamic parameters in the fetal descending aorta derived from color Doppler velocity profiles.

This paper presents a methodology for estimating the wall shear stress in the fetal descending aorta from color Doppler velocity profiles obtained during the second half of pregnancy. The Womersley model was applied to determine the wall shear stress and related hemodynamic parameters. Our analysis indicates that the aortic diameter can be modeled as a function of the gestational age in weeks as: Diameter (mm) = 0.17.ga + 0.15 (R2 = 0.64, p < 0.001). The aortic volume flow showed a log linear gestational age-related increase that fit the model: F (mL/min) = e(0.08.ga + 3.49) (R2 = 0.61, p < 0.001). The Womersley number increased linearly with gestational age from 3.3 to 6.2 (p < 0.001) and the pressure gradient decreased linearly from 2.68 to 1.16 mPa/mm (p = 0.003) during the second half of pregnancy; the mean wall shear stress for the study group was 2.2 Pa (SD = 0.59) and was independent of gestational age. This study suggests that the size of the fetal aorta adapts to flow demands and maintains constant mean wall shear stress.

Mild renal pyelectasis in the second trimester: determination of cut-off levels for postnatal referral.

OBJECTIVE: To establish guidelines for postnatal referral of fetuses presenting with mild pyelectasis in the second trimester of pregnancy. METHODS: In a retrospective study, 87 fetuses with a renal pelvis anteroposterior (RPAP) diameter of > or = 4 mm and < or = 10 mm before 28 weeks of gestation were included. All patients had a third-trimester scan and fetuses with an RPAP diameter of > or = 10 mm at that stage were referred for postnatal assessment. The family practitioner of all infants with an RPAP of < 10 mm in the third trimester was contacted for follow-up information. The RPAP diameter most predictive of renal pathology was determined with receiver-operating characteristics (ROC) curve analysis for both the first and second scans. RESULTS: In 36 of 87 infants, 49 abnormal kidneys were diagnosed. Seven infants required surgery on eight renal tracts. The ROC curves of the first scan, second scan and differences between scans resulted in an area under the curve of 0.60, 0.87 and 0.85, respectively. The sensitivities and specificities for a cut-off level of 8, 9 and 10 mm at the second scan were 80%, 71% and 61% and 79%, 90% and 93%, respectively. At a cut-off level of 10 mm, only cases of insignificant minimal dilatation and a case of vesicoureteric reflux (VUR) requiring surgery were not detected. CONCLUSION: After establishing a diagnosis of mild pyelectasis before 28 weeks, a second scan is mandatory to determine which infants need postnatal evaluation. A cut-off level of 8 mm has a low specificity but includes most cases of pathology. A cut-off level of 10 mm detects most significant pathology; however, VUR may not be detected.

The role of three-dimensional ultrasound in visualizing the fetal cranial sutures and fontanels during the second half of pregnancy.

OBJECTIVES: The aim of this study was to evaluate the significance of three-dimensional (3D) ultrasound in visualizing fetal cranial sutures and fontanels and to determine factors that could influence visualization and image quality. METHODS: Serial 3D ultrasound examinations were evaluated for visibility of fetal cranial sutures and fontanels, image quality and possible influencing parameters in the second half of pregnancy. Thirty fetuses were scanned at four different gestational ages providing a data set of 120 cases. RESULTS: Most (82-100%) cranial sutures and fontanels could be visualized with 3D ultrasound. However, the sagittal suture and posterior fontanel were visualized in only 47% and 42%, respectively. Gestational age significantly influenced the visibility of the sutures and fontanels, image quality decreasing with advancing gestational age. CONCLUSIONS: 3D ultrasound can be a reliable technique for visualizing most fetal cranial sutures and fontanels. By performing a sagittal and a transverse scan, most of the sutures and fontanels can be made visible during the second half of pregnancy. Visualization depends on gestational age.

Preeclampsia and its interaction with common variants in thrombophilia genes.

Recently, it has been proposed that abnormalities in coagulation and fibrinolysis contribute to the development of preeclampsia by increasing the thrombotic tendency. This hypothesis was tested in women who have had preeclampsia (cases) compared with matched controls. Polymorphisms in the thrombophilia genes [plasminogen activator inhibitor type 1 [PAI-1 -675(4G/5G)], thrombin activatable fibrinolysis inhibitor (TAFI -438G/A and 1040C/T), methylenetetrahydrofolate reductase (MTHFR 677C/T), factor V (FV Leiden R/Q506), prothrombin (FII 20210G/A) and factor XIIIA (FXIIIA V/L34)] were determined in 157 women with preeclampsia and 157 women with uncomplicated pregnancy. The associated risk of preeclampsia was analyzed using logistic regression methods. The frequency distributions of the genotypes of these six polymorphisms in thrombophilia genes were similar in the case and control groups. We found no differences in the prevalence of genetic risk factors of thrombosis in women with preeclampsia compared with controls, which makes it unlikely that these polymorphisms are risk factors for preeclampsia.

Fetal heart rate and umbilical artery flow velocity variability in intrauterine growth restriction: a matched controlled study.

OBJECTIVES: To study heart rate and umbilical artery blood flow velocity variability in growth-restricted fetuses and investigate the influence of the autonomic nervous system on these parameters. METHODS: Doppler velocity waveforms were collected from long-lasting umbilical artery recordings in 15 fetuses with growth restriction and 15 normal age-matched controls at 23-35 weeks of gestation. Absolute heart rate and umbilical artery blood flow velocity as well as the coefficient of variation were determined. Using power spectral analysis the low- and high-frequency bands of heart rate variability and blood flow velocity variability were calculated. The low-to-high (LH) ratio of heart rate variability and blood flow velocity variability were examined as a measure of sympathovagal balance. RESULTS: In growth-restricted fetuses umbilical artery velocities were significantly reduced. Heart rate variability was significantly reduced in the presence of growth restriction, but no significant difference was demonstrated for blood flow velocity variability. The LH ratio for heart rate variability was significantly decreased in growth restriction, but no difference in LH ratio was demonstrated for blood flow velocity variability. CONCLUSION: Flow velocity variability in growth restriction seems not to be predominantly influenced by the autonomic nervous system, whereas the decreased heart rate variability seems to be influenced by altered sympathetic-parasympathetic balance.

The impact of maternal plasma volume expansion and antihypertensive treatment with intravenous dihydralazine on fetal and maternal hemodynamics during pre-eclampsia: a clinical, echo-Doppler and viscometric study.

OBJECTIVES: To establish the effects of plasma volume expansion (PVE) followed by intravenous dihydralazine (DH) administration on maternal whole blood viscosity (WBV) and hematocrit, uteroplacental and fetoplacental downstream impedance and umbilical venous (UV) volume flow in pre-eclampsia. METHODS: In 13 pre-eclamptic women maternal and fetal hemodynamics were established by means of combined measurement of maternal arterial blood pressure (BP), WBV, hematocrit and uterine artery (UtA) resistance index (RI) in addition to umbilical artery (UA) pulsatility index (PI) and UV volume flow obtained from UV vessel area and UV time-averaged flow velocity. In each woman all parameters were measured four times at baseline, after PVE, after DH and 24 h after the start of treatment. RESULTS: Maternal diastolic BP, hematocrit and WBV display a significant reduction after PVE. In the fetus UA PI decreases significantly whereas a significant increase in UV cross-sectional area was detected. After maternal DH administration, arterial systolic and diastolic BP and UA PI show a significant decrease compared with the measurements following PVE. At 24 h, only maternal systolic and diastolic BP display a significant further decrease. No significant changes were established for the UtA RI, UV time-averaged velocity and UV volume flow during the entire study period. CONCLUSIONS: During pre-eclampsia, maternal PVE followed by DH administration results in a significant reduction in maternal diastolic BP, maternal hematocrit and WBV. Maternal PVE is associated with a significant increase in UV cross-sectional area and a non-significant rise of 11% in UV volume flow. Maternal DH administration does not result in any change in UV cross-sectional area. However, UA PI decreases significantly after both PVE and DH treatment.

Fetal heart rate and blood flow velocity variability in the presence of increased nuchal translucency: a preliminary study.

OBJECTIVE: To study the power spectrum distribution of heart rate and umbilical artery flow velocity variability in fetuses with increased nuchal translucency thickness (NT). METHODS: Doppler velocity waveforms were collected from long-lasting (>20 s) umbilical artery recordings in 18 fetuses with increased NT (>3 mm) and 18 normal controls matched for gestational age at 11-14 (median, 12) weeks. The NT group included 11 abnormal karyotypes: trisomy 18 (n = 3), 45,X (n = 4), trisomy 21 (n = 3) and a balanced translocation. Absolute heart rate as well as the coefficient of variation for both beat-to-beat heart rate variability and umbilical artery blood flow velocity variability were determined. The ratios of the integrated low-frequency components (0.05-0.2 Hz) and the integrated high-frequency ones (0.25-1.6 Hz; LH ratio) from normalized power spectrum distributions were established to reflect sympathovagal balance. RESULTS: The mean heart rate was not significantly different between the two groups. However, mean heart rate variability and time-averaged flow velocity variability were significantly increased in the NT group, while there was no significant difference in the LH ratios between the two groups. The mean umbilical artery pulsatility index was significantly higher in the NT group. CONCLUSION: The autonomic nervous system does not seem to play a role in the altered cardiovascular homeostasis in the presence of increased fetal NT.

Umbilical venous volume flow and fetal behavioral states in the normally developing fetus.

OBJECTIVE: To determine the relationship between umbilical venous (UV) volume flow and fetal behavioral states 1F (quiet sleep) and 2F (active sleep) in normal pregnancies at 36-40 weeks of gestation. METHODS: Fetal behavioral states were established in 17 normal pregnancies by means of combined assessment of fetal heart rate patterns (FHRP), and fetal eye and body movements. UV vessel area (mm(2)) as obtained by tracing the inner vessel area using Labview and Imaq Vision software and UV time-averaged flow velocity (mm/s Doppler) were multiplied to calculate UV volume flow (mL/min) including flow/kg fetus. The pulsatility index (PI) in the umbilical artery was also determined. In each woman, all parameters were measured between three and five times in each behavioral state. Data are reported as mean +/- 1 SD and analyzed by paired t-test. RESULTS: No statistically significant behavioral-state-related changes were observed for UV time-averaged velocity and UV volume flow, resulting in UV volume flow/kg fetus of 69.1 +/- 14.9 mL/min*kg at 1F and 71.6 +/- 12.1 mL/min*kg at 2F (not significant). A statistically significant increase (P = 0.02) was established for UV cross-sectional area (46.4 +/- 8.6 mm(2) vs. 49.0 +/- 10.1 mm(2)) and for fetal heart rate (FHR) from 134.2 +/- 10.3 bpm in 1F to 144.2 +/- 7 bpm in 2F. Umbilical artery PI was not significantly different between the two behavioral states. CONCLUSIONS: On the basis of high venous vessel wall compliance, the significant increase in UV cross-sectional area during fetal behavioral state 2F may be determined by a rise in mean venous pressure. The significant rise in FHR may reflect increased fetal cardiac output during state 2F while the resistance at the hepato-ductal pathway remains relatively constant with the purpose of meeting raised energy demands during the active sleep state. This is further supported by the observed trend towards an increase in UV volume flow.

[Twenty years of experience in advanced ultrasound scanning for fetal anomalies in Rotterdam]. / Geavanceerd ultrageluidonderzoek naar aangeboren afwijkingen in Rotterdam; 20 jaar ervaring.

At the Rotterdam Fetal Medicine Unit over a period of 20 years, scanning for foetal anomalies has been performed in more than 24,000 pregnancies at risk of a foetal congenital anomaly. In pregnancies where there was prior knowledge of increased risk of a foetal anomaly (group I), the incidence of foetal pathology was 2-5%. In pregnancies in which a foetal anomaly was suspected on clinical or sonographic grounds (group II), the incidence of foetal pathology was 32-57%. For reasons of good-image quality, group I pregnancies were nearly always referred for a foetal-anomaly scan at 18-21 weeks of gestation. Group II pregnancies were often referred after 24 weeks of gestation, which is the upper legal limit for termination of pregnancy in the Netherlands. The detection rate was 94.7% (2000 and 2001). An abnormal chromosome pattern was established in 18% of all affected pregnancies, the great majority of these patterns (83%) being numerical. Approximately 18% of affected pregnancies were discussed in a multidisciplinary setting to ensure correct diagnosis, prognosis and management. Depending on the nature and severity of the foetal anomaly, standard obstetric management was advised in two thirds of cases. In the remaining one third termination of pregnancy was carried out at the request of the parents or a policy of obstetric non-intervention was adopted. In a subgroup comprising 460 pregnant women with both indications for referral, who were investigated at 12-14 weeks gestation, the detection rate for a number of congenital abnormalities was 89.5%.