Immunogenicity, Reactogenicity, and Safety of AS01E-adjuvanted RSV Prefusion F Protein-based Candidate Vaccine (RSVPreF3 OA) When Co-administered With a Seasonal Quadrivalent Influenza Vaccine in Older Adults: Results of a Phase 3, Open-Label, Randomized Controlled Trial

BACKGROUND

Co-administration of vaccines against respiratory syncytial virus (RSV) and influenza can be considered given their overlapping seasonality, and may increase vaccine uptake and compliance. In this phase 3, open-label, randomized study, we evaluated the immunogenicity, reactogenicity, and safety of the AS01E-adjuvanted RSV prefusion F protein-based candidate vaccine (RSVPreF3 OA) when co-administered with a seasonal quadrivalent influenza vaccine (FLU-QIV) in older adults.

METHODS

Participants aged ≥60 years (randomized 1:1) received either RSVPreF3 OA and FLU-QIV simultaneously on day 1 (Co-Ad group) or FLU-QIV on day 1 followed by RSVPreF3 OA on day 31 (sequential administration [SA] group). The co-primary objectives were to demonstrate noninferiority of RSVPreF3 OA in terms of RSV-A neutralization geometric mean titer (GMT) ratio and FLU-QIV in terms of hemagglutination inhibition GMT ratio for each FLU-QIV strain, when co-administered versus when administered alone at 1-month post-vaccination. Noninferiority was demonstrated if the upper limit of the 95% confidence interview of the group GMT ratio (SA/Co-Ad) was ≤1.5. Secondary descriptive objectives comprised additional immunogenicity assessments, reactogenicity, and safety.

RESULTS

Of the 885 participants who received one dose of the study vaccines, 837 were included in the per protocol set. Demographic and baseline characteristics were balanced between the groups. Both co-primary objectives were met for both vaccines. Reported adverse events in both groups were mild-to-moderate, with a low frequency of grade 3 events.

CONCLUSIONS

Data from this study demonstrate that RSVPreF3 OA can be co-administered with FLU-QIV. Co-administration is well tolerated, with an acceptable safety profile.

CLINICALTRIALS.GOV REGISTRATION

NCT04841577.

2139. Immunogenicity, reactogenicity and safety of a Respiratory Syncytial Virus prefusion F (RSVPreF3) candidate vaccine co-administered with the seasonal quadrivalent influenza vaccine in older adults

Background

Respiratory syncytial virus (RSV) can cause severe respiratory disease in older adults (OAs). However, there is no approved vaccine against RSV disease in OAs. Co-administration of vaccines against RSV and influenza could be considered given their overlapping seasonality. Here, we assessed the immunogenicity, reactogenicity and safety of an RSV prefusion F Older Adult (RSVPreF3 OA) investigational vaccine when co-administered with the seasonal quadrivalent influenza vaccine (FLU-QIV) in OAs.

Methods

In this Phase 3, open-label, controlled, multi-country study (NCT04841577), OAs aged ≥ 60 years recruited in New Zealand, Panama and South Africa were randomized 1:1 to receive either RSVPreF3 OA and FLU-QIV simultaneously on day 1 (Co-Ad group), or FLU-QIV on day 1 and RSVPreF3 OA on day 31 (Control group). The co-primary objectives were to demonstrate the non-inferiority of i) RSVPreF3 OA in terms of RSV-A neutralizing antibody geometric mean titers (GMT) ratio and ii) FLU-QIV in terms of hemagglutinin inhibition antibody GMT ratio for each Flu strain when co-administered versus when administered alone. Blood samples were collected from all participants pre vaccination and 1 month post vaccination. Non-inferiority was demonstrated if the upper limit (UL) of the 95% confidence interval (CI) of the group GMT ratio (Control/Co-Ad) was ≤ 1.5. Secondary descriptive outcomes included reactogenicity and safety.

Results

885 participants received at least 1 dose of the study interventions. Of these, 838 were included in the per protocol set at 1 month post vaccination. The demographic characteristics of the participants were similar across groups. The study co-primary objectives were met; for both vaccines, the UL of the 95% CI of the GMT ratio was ≤ 1.5 (Table 1). The observed safety events were balanced between Co-Ad and Control groups (Table 2). The reactogenicity profile of the Co-ad group compared with the Control group was driven by the RSVPreF3 OA investigational vaccine.

Conclusion

Our results support simultaneous seasonal vaccination with RSVPreF3 OA and FLU-QIV in adults ≥ 60 years, as co-administration elicits a statistically non-inferior immune response to the administration of each vaccine alone, with no safety concerns identified.

Disclosures

Nathali Montenegro, MD, GSK: Support for the present abstract/study Lorena Noriega-Aguirre, MD, ScD, Astra Zeneca: Advisor/Consultant|Astra Zeneca: Honoraria|Astra Zeneca: Support for attending meetings and/or travel|Boehringer Ingelheim: Honoraria|Boehringer Ingelheim: Support for attending meetings and/or travel|GSK: Advisor/Consultant|GSK: Support for the present abstract/study|Novartis: Honoraria Mohammed Bensellam, PhD, GlaxoSmithKline Biologicals SA: Agency worker on assignment at GSK Nathalie De Schrevel, PhD, GlaxoSmithKline Biologicals SA: Employee|GlaxoSmithKline Biologicals SA: Ownership Interest Sherine Kuriyakose, MSc, GSK: GSK Employee Axel Lambert, MSc, GSK: GSK Employee Aurélie Olivier, PhD, GlaxoSmithKline Biologicals SA: I’m an employee of GSK Biologicals|GlaxoSmithKline Biologicals SA: Ownership Interest Veronica Hulstrøm, PhD MD, GlaxoSmithKline Biologicals SA: Employee.

Safety and immunogenicity of a tetravalent dengue vaccine in children aged 2-17 years: a randomised, placebo-controlled, phase 2 trial

BACKGROUND

An unmet clinical need remains for an effective tetravalent dengue vaccine suitable for all age groups, regardless of serostatus. We assessed the immunogenicity and safety of three different dose schedules of a tetravalent dengue vaccine (TAK-003) over a 48-month period in children living in dengue-endemic countries.

METHODS

We did a large, phase 2, double-blind, placebo-controlled trial at three sites in the Dominican Republic, Panama, and the Philippines. Healthy participants aged 2-17 years were randomly assigned 1:2:5:1 using an interactive web response system with stratification by age to receive either a two-dose primary series (days 1 and 91), one primary dose (day 1), one primary dose plus booster (days 1 and 365), or placebo. Participants and relevant study personnel were masked to the random assignment until completion of the study at month 48. To maintain masking, TAK-003 recipients were administered placebo doses when appropriate. The primary objective was assessment of neutralising geometric mean titres for each serotype to month 48 assessed in the per-protocol immunogenicity subset. Secondary safety endpoints included proportions of participants with serious adverse events and symptomatic virologically confirmed dengue. This study is registered with ClinicalTrials.gov, NCT02302066.

FINDINGS

Between Dec 5, 2014, and Feb 13, 2015, 1800 children were randomly assigned to the following groups: two-dose primary series (n=201), one primary dose (n=398), one primary dose plus 1-year booster (n=1002), and placebo (n=199). Of them, 1479 (82%) participants completed the 48-month study. Immunogenicity endpoints were assessed in 562 participants enrolled in the immunogenicity subset, of whom 509 were included in the per-protocol subset. At month 48, antibody titres remained elevated in all TAK-003 groups compared with placebo, irrespective of baseline serostatus. At month 48, geometric mean titres were 378 (95% CI 226-632) in two-dose, 421 (285-622) in one-dose, 719 (538-960) in one-dose plus 1-year booster, and 100 (50-201) in placebo recipients against DENV 1; 1052 (732-1511), 1319 (970-1794), 1200 (927-1553), and 208 (99-437) against DENV 2; 183 (113-298), 201 (135-298), 288 (211-392), and 71 (37-139) against DENV 3; and 152 (97-239), 164 (114-236), 219 (165-290), and 46 (26-82) against DENV 4; and tetravalent seropositivity rate was 89% (79-96), 86% (80-92), 97% (93-99), and 60% (47-72), respectively. Virologically confirmed dengue was recorded in 37 (2%) TAK-003 and 13 (7%) placebo participants, with a relative risk of 0·35 (0·19-0·65). No vaccine-related serious adverse events or severe dengue virus disease were reported.

INTERPRETATION

TAK-003 elicited antibody responses against all four serotypes, which persisted to 48 months post-vaccination, regardless of baseline serostatus. No important safety risks were identified. We observed a long-term reduction in risk of symptomatic dengue virus disease in vaccinees. Results from this study provide a long-term safety database and support assessment of the vaccine in the ongoing phase 3 efficacy study.

FUNDING

Takeda Vaccines.

Lateral ventricles in fetuses with aneuploidies at 11-13 weeks' gestation

OBJECTIVE

To examine the possible association between aneuploidies and fetal lateral cerebral ventriculomegaly in the first trimester of pregnancy.

METHODS

Three-dimensional brain volumes were acquired by transvaginal ultrasound examination at 11-13 weeks' gestation in 410 euploid fetuses and 63 fetuses with trisomy 21, 34 with trisomy 18 and seven with trisomy 13. Lateral ventricles were assessed in a transverse view, just above the roof of the third ventricle and measurements of the areas of the lateral ventricles and choroid plexuses were obtained. The ratio between choroid plexus and lateral ventricle areas (CLR) was calculated. Measurements in aneuploid fetuses were compared to those in euploid fetuses.

RESULTS

In euploid fetuses the lateral ventricle and choroid plexus areas increased, whereas the CLR decreased with fetal biparietal diameter. In fetuses with trisomy 21, lateral ventricle and choroid plexus areas were smaller but CLR was not significantly different from that in euploid fetuses. In trisomy 18 and 13 fetuses, CLR was significantly smaller than in euploid fetuses. The CLR was below the 5(th) centile of normal range in 11 (32.4%) fetuses with trisomy 18 and in six (85.7%) with trisomy 13.

CONCLUSION

There is evidence of ventriculomegaly at 11-13 weeks' gestation in most fetuses with trisomy 13 and one third of fetuses with trisomy 18.

Cerebral ventricular system in fetuses with open spina bifida at 11-13 weeks' gestation

OBJECTIVE

To determine if in fetuses with open spina bifida at 11-13 weeks' gestation there are alterations in the cerebral ventricular system.

METHODS

In this study we selected 10 cases of open spina bifida and 410 normal singleton pregnancies which subsequently resulted in the delivery of phenotypically normal neonates. In all cases transvaginal sonography was carried out at 11-13 weeks' gestation and three-dimensional (3D) brain volumes were acquired. The fetal head was systematically assessed in a series of transverse views and measurements were obtained of the area of the lateral ventricles, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle. The measurements obtained on the normal and affected fetuses were compared.

RESULTS

In normal fetuses the area of the lateral ventricles and the diameter of the roof of the third ventricle increased, the diameter of the aqueduct of Sylvius decreased and the diameter of the fourth ventricle did not change significantly with biparietal diameter (BPD). In fetuses with open spina bifida, compared with normal fetuses, the measurements of the lateral ventricle area, the diameter of the roof of the third ventricle, the diameter of the aqueduct of Sylvius and the diameter of the fourth ventricle were significantly decreased (P < 0.01).

CONCLUSION

In fetuses with open spina bifida at 11-13 weeks' gestation the intracranial collection of cerebrospinal fluid is substantially reduced.

Phenotypic variability in fetuses with down syndrome: a case-control pathological evaluation

OBJECTIVES

Evaluation of morphological and morphometric characteristics of fetuses with Down syndrome based on a detailed postmortem examination and comparison of these fetuses with a control group of fetuses with normal karyotype to improve the prenatal knowledge of Down syndrome characteristics.

MATERIAL AND METHODS

A case-control study was undertaken in a tertiary referral hospital. The Down syndrome fetuses (50) were compared with chromosomally normal fetuses (47) matched for gestational age. Biometric and morphological parameters were compared.

RESULTS

The biometry of fetuses with Down syndrome differs from control fetuses only in the occipitofrontal diameter and in the nasal bone length. There were craniofacial anomalies in 96% of fetuses with Down syndrome and in 51% of fetuses with normal karyotype. With the exception of small ears, all craniofacial features analyzed were significantly different between Down syndrome fetuses and control fetuses. All extremity features of fetuses with Down syndrome were significantly different from fetuses without Down syndrome. There were 31 fetuses with Down syndrome (62%) with 55 internal anomalies. Nineteen fetuses (38.8%) showed 27 cardiac anomalies. Six fetuses had more than one anomaly. There were 18 fetuses (36%) with 28 noncardiac anomalies.

DISCUSSION

The importance of studying the morphological characteristics of fetuses with Down syndrome is the contribution to a better knowledge of fetal characteristics and probably to optimize prenatal diagnosis.

Screening for twin-twin transfusion syndrome at 11-14 weeks of pregnancy: the key role of ductus venosus blood flow assessment

OBJECTIVES

A discrepancy in crown-rump length (CRL) and/or nuchal translucency thickness (NT) between monochorionic twins has been found to be associated with an increased risk of twin-twin transfusion syndrome (TTTS). As one of the most plausible mechanisms for increased NT is hemodynamic imbalance and cardiac dysfunction, indirectly manifested by abnormal blood flow in the ductus venosus (DV), we aimed to clarify the role of DV blood flow assessment in identifying those monochorionic twins more prone to develop TTTS.

METHODS

We present 99 cases of monochorionic diamniotic twin pregnancies in which CRL, NT and DV blood flow were evaluated at 11-14 weeks' gestation.

RESULTS

Discrepant values of CRL were not predictive of TTTS development. Intertwin NT discrepancy >or= 0.6 mm had a sensitivity of 50.0% and a specificity of 92.0%. The presence of at least one abnormal blood flow waveform in the DV was associated with a relative risk for developing TTTS of 11.86 (95% CI, 3.05-57.45), with a sensitivity of 75.0% and a specificity of 92.0%. The combination of abnormal DV blood flow with NT discrepancy >or= 0.6 mm yielded a relative risk for the development of TTTS of 21 (95% CI, 5.47-98.33).

CONCLUSIONS

Both intertwin discrepancy in NT and abnormal flow in the DV in monochorionic twins may represent early manifestations of hemodynamic imbalance between donor and recipient. In these pregnancies, in addition to NT measurement at 11-14 weeks, the Doppler assessment of DV blood flow significantly increases the performance of screening for those at risk of developing TTTS.

Concordance for bilateral congenital diaphragmatic hernia in a monozygotic dichorionic twin pair - first clinical report

The authors present a clinical case of concordance for bilateral congenital diaphragmatic hernia in a monozygotic twin pair diagnosed in the early second trimester.

Recipient's vascular doppler pattern immediately following death of the donor in a case of untreated severe twin-to-twin transfusion syndrome

In a stage III twin-to-twin transfusion syndrome, death of the donor at 31 weeks was followed by unusual umbilical artery (UA) doppler findings in the recipient, with a high diastolic peak velocity and a low S/D ratio. Besides, middle cerebral artery waveforms could not be obtained in the recipient. The recipient was delivered by emergency cesarean section, weighed 1,230 g, was strikingly pale and had a cord hemoglobin concentration of 15 g/dl. Neonatal blood average pressure was of 29 mm Hg, immediately after delivery, and ranged from 33 to 43 mm Hg in the first 12 h of life. Neonatal heart function returned to normal on day 2. We hypothesize that death of the donor twin induced an acute decrease in placental resistance. This phenomenon, combined with decreased systolic blood flow due to the recipient's systolic function impairment, could account for the umbilical artery flow pattern we observed. The acute decrease in volemia and the presence of systemic hypertension and cardiomyopathy may explain the inability to obtain middle cerebral artery doppler. This complex hemodynamic disturbance in the recipient may be responsible for morbidity unrelated to anemia in case of donor's demise, as acute fetal distress.

Renal tubular dysgenesis: report of two cases in a non-consanguineous couple and review of the literature

Renal tubular dysgenesis is a rare congenital abnormality of renal development characterized by short and poorly developed proximal convoluted tubules. It is associated to late-appearing oligohydramnios, Potter's sequence, pulmonary hypoplasia and calvarial bone hypoplasia with enlarged fontanels. The onset of oligohydramnios is delayed and variable, normally later than 22 weeks of gestation, conditioning variation in the expression of the other deformities. We report 2 cases of renal tubular dysgenesis occurring in a non-consanguineous couple.

How should success be defined when attempting medical resolution of first-trimester missed abortion?

OBJECTIVES

There is currently no consensus on how success should be defined after medical management of first-trimester missed abortion. The aim of this study was to determine the transvaginal ultrasound criterion associated with highest success rate and, at the same time, lowest long-term complications.

DESIGN

Prospective observational study of consecutively enrolled patients.

SETTING

A tertiary care university hospital in northern Portugal.

PARTICIPANTS

Forty-four women submitted to medical management of first-trimester missed abortion using a regimen of vaginal misoprostol, with histologically confirmed conception products passed vaginally. A transvaginal ultrasound scan was performed by an experienced sonographer in the morning after treatment, to characterise uterine content. Patients were provided with a chart for daily registration of axillary temperature, vaginal bleeding and lower abdominal pain. Transvaginal ultrasound was repeated 2-3 weeks later, and again after the following menses.

MAIN OUTCOME MEASURES

Success rates of medical management when post-treatment transvaginal ultrasound criteria for subsequent expectant management were: absence of intra-uterine sac, largest anteroposterior diameter of hyperechogenic content, and maximum area of hyperechogenic intra-uterine content in a sagittal view. Self-reported duration of vaginal bleeding and abdominal pain after medical treatment.

RESULTS

Success rate was 86% (38/44) when absence of gestational sac on the 12 h transvaginal ultrasound was used as the main criterion for subsequent expectant management and there was no need for further intervention. The success rate using the ultrasound criterion anteroposterior diameter < or = 15 mm was 51% (22/43), and with maximum sagittal plane area under 7.5 cm(2), 72% (31/43). Mean duration of vaginal haemorrhage was 9 days (minimum 2 days, maximum 14 days) and of lower abdominal pain 6 days (minimum 0 days, maximum 14 days). No patient recorded an axillary temperature exceeding 37 degrees C. No apparent relationship between the size of ultrasound-estimated intra-uterine content and duration of symptoms was observed.

CONCLUSIONS

Absence of gestational sac on transvaginal ultrasound should be the criterion used to document success after medical management of first-trimester missed abortion, as it is associated with the highest short and long-term success rates, as well as mild and self-limited symptoms in the days following treatment.

Ductus venosus blood flow in chromosomally abnormal fetuses at 11 to 14 weeks of gestation

This article reviews the role of ductus venosus (DV) Doppler evaluation in the screening for aneuploidies at 11 to 14 weeks of gestation. Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 515 consecutive singleton pregnancies at 11 to 14 weeks. We found 446 normal and 69 abnormal karyotypes. Abnormal flow in the DV was the only significant difference between both groups. Sensitivity of the test was 80% and false positive rate < 1%. Normal karyotype but abnormal flow in the DV was recorded in 17 of 446 cases, 7 presenting a cardiac defect. Increased nuchal translucency seems to be related, in most cases, to early cardiac dysfunction. Chromosomal abnormalities and/or cardiac defects were often found in cases with increased nuchal translucency and abnormal flow in the DV. We suggest that the evaluation of ductal flow between 11 to 14 weeks of gestation should be adopted as a second level screening test to reduce invasive test rate derived from the exclusive measurement of nuchal translucency.

Anticipating twin-twin transfusion syndrome in monochorionic twin pregnancy. Is there a role for nuchal translucency and ductus venosus blood flow evaluation at 11-14 weeks?

Twin-twin transfusion syndrome is a major complication of monochorionic twin pregnancies. In foetuses from monochorionic twinning the presence of increased nuchal translucency thickness (NT) has been associated with an increased risk of developing this syndrome. One of the presumed mechanisms of increased NT is early cardiac failure, indirectly indicated by abnormal blood flow in the ductus venosus. We present eleven cases of monochorionic twin pregnancies in which nuchal translucency thickness and ductus venosus blood flow evaluation was performed at 11-14 weeks. In the two cases presenting with nuchal translucency discrepancy between the two foetuses along with anomalous ductus venosus blood flow in the foetus with increased nuchal translucency, twin-twin transfusion syndrome (TTTS) eventually developed. In none of the twins displaying no inter-twin difference in NT measurements and in those with discrepant NT but normal flow in both ductus venosus, was the progression to TTTS observed. In the two cases which developed TTTS, foetoscopic laser coagulation of the vascular anastomosis was successfully carried out at 18 weeks and normalisation of the venous return was registered. These findings suggest that the association of increased NT and abnormal flow in the ductus venosus in monochorionic twins may be an early manifestation of haemodynamic imbalance between the donor and the recipient eventually manifested as twin-twin transfusion syndrome. Further studies, however, are necessary to establish the potential role of the combination of NT and ductus venosus blood flow assessment as a screening method for TTTS.

Haemodynamic evaluation of the first trimester fetus with special emphasis on venous return

Knowledge of the fetal circulation is a prerequisite for understanding the physiological behaviour of the developing fetus. In this overview dealing with Colour and Power Doppler ultrasound findings in the first trimester of pregnancy and its pathophysiological background, we aim to report on the methodological aspects, normal blood flow waveform patterns, normal reference values for haemodynamic parameters and potential clinical applications for both arterial and venous flow information (umbilical artery, descending aorta, middle cerebral artery, umbilical vein, inferior vena cava, ductus venosus) and atrioventricular valves. Particular emphasis is devoted to the venous return to the heart. Alterations in venous waveforms, particularly in the ductus venosus, are correlated with the pathophysiology of some fetal diseases and are suggested as a promising tool for the screening of cardiac impairment and as an alternative method for fetal biophysical surveillance.

Prenatal diagnosis of congenital heart disease. Critical evaluation of a twelve-month experience

INTRODUCTION

A retrospective study of fetal echocardiographies performed in the Ultrasound Unit of the Department of Obstetrics and Gynecology between January and December 1998 was carried out.

MATERIAL AND METHODS

We performed 271 fetal echocardiographies (236 fetuses; 230 pregnant women). A triplex ultrasound machine was used with a 5 or 3.5 MHz transabdominal probe.

RESULTS

The median maternal age was 31 years (17-44) and the median gestational age at the time of the first examination was 27 weeks (15-38). A hundred and thirty-two pregnant women (57.4%) were internal referrals and (98) 42.6% were referred by other hospitals. The most common indications for referral were maternal age > or = 35 years old (n = 48), gestational diabetes (n = 38), family history of congenital heart disease (n = 24) and insulin-dependent diabetes (n = 23). Accuracy of 32 echocardiographies was limited by technical difficulties. Out of 236 fetuses, 205 (86.9%) presented a normal scan, whereas 31 (13.1%) showed some abnormality: 22 structural cardiac defects; 5 rhythm anomalies and one with a mixed abnormality. In three cases a pericardial effusion was detected in the absence of any structural or rhythm anomaly and regressed spontaneously after birth. Three fetuses were referred prenatally for treatment to another center. Eight out of fifteen patients followed in the Pediatric Cardiology outpatient clinic were submitted to surgical treatment. In four cases the parents opted for termination of pregnancy and two neonatal deaths occurred. Four patients were lost for follow-up.

DISCUSSION

Our study suggests that strict criteria for a referral of pregnant women to specialized fetal echocardiography are still missing. The median gestational age of 27 weeks at the time of the first examination was clearly out of the generally accepted recommended period (18-24 weeks). It is time to improve the collaboration between the different health professionals involved in the care of pregnant women in order to increase the sensitivity of screening for congenital heart disease.

Neonatal cerebral Doppler: arterial and venous flow velocity measurements using color and pulsed Doppler system

OBJECTIVE

To contribute to the establishment of reference values of blood flow velocity assessed by cerebral Doppler in healthy infants related to gestational age and birth weight during the first week of life.

METHODS

Five arteries and three veins were evaluated respectively in 120 (74 premature) newborns and in 100 (70 preterm) infants. In a quarter of the latter three recordings at 5-minute intervals were made to assess reproducibility. The relation between flow measurements and gestational age was assessed by linear regression, means by analysis of variance (or Kruskall-Wallis test) and paired samples by Student's t test.

RESULTS

There was a significant increase of arterial velocities with increasing gestational age and birth weight, but not for venous velocities. Significant higher values were found in the internal carotid artery followed by the medium cerebral artery. The venous velocities were highly reproducible and the main patterns observed were bandlike and sinusoid type.

CONCLUSION

The knowledge of normal cerebrovascular physiology is essential to understand the pathogenesis of neonatal brain damage and can help pediatricians in an accurate interpretation of the flow profile in neurological pathology.

Cardiac defects in chromosomally normal fetuses with abnormal ductus venosus blood flow at 10-14 weeks

OBJECTIVE

To assess a possible relationship between ductus venosus blood flow abnormalities and cardiac defects in chromosomally normal fetuses with increased nuchal translucency thickness at 10-14 weeks of gestation.

METHODS

Ductus venosus Doppler ultrasound blood flow velocity waveforms were obtained at 10-14 weeks' gestation immediately before fetal karyotyping in 200 consecutive singleton pregnancies with increased nuchal translucency. Fetal echocardiography was subsequently carried out in those with normal fetal karyotype.

RESULTS

Reverse or absent flow during atrial contraction was observed in 11 of the 142 chromosomally normal fetuses with increased nuchal translucency. Major defects of the heart and/or great arteries were present in seven of the 11 with abnormal ductal flow and increased nuchal translucency, but in none of the 131 with normal flow.

CONCLUSION

These preliminary results suggest that abnormal ductus venosus blood flow in chromosomally normal fetuses with increased nuchal translucency identifies those with an underlying major cardiac defect.

Screening for chromosomal abnormalities at 10-14 weeks: the role of ductus venosus blood flow

OBJECTIVE

To assess the possible role of Doppler ultrasound assessment of ductus venosus blood flow in screening for chromosomal abnormalities at 10-14 weeks of gestation.

METHODS

Ductus venosus flow velocity waveforms were obtained immediately before fetal karyotyping in 486 consecutive singleton pregnancies at 10-14 weeks of gestation. All cases were screened for chromosomal defects by a combination of maternal age and fetal nuchal translucency thickness. The peak systolic and diastolic velocities, the velocity during atrial contraction and the pulsatility index were measured.

RESULTS

There were 63 chromosomal defects (38 cases of trisomy 21, 12 cases of trisomy 18, seven cases of trisomy 13, three cases of Turner's syndrome and three cases of triploidy). In 57 (90.5%) cases there was reverse or absent flow during atrial contraction. Abnormal ductus venosus flow was also observed in 13 (3.1%) of the 423 chromosomally normal fetuses. In the chromosomally abnormal group, compared to the normal group, the median heights of the S and D waves were significantly lower and the pulsatility index was significantly higher. However, multivariate regression analysis demonstrated that only the height of the A wave provided a significant independent contribution in distinguishing between the chromosomally normal and abnormal groups.

CONCLUSION

These preliminary results suggest that assessment of ductus venous blood flow in pregnancies considered to be at high risk for chromosomal defects may result in a major reduction in the need for invasive testing, with only a small decrease in sensitivity.

Venous return and right ventricular diastolic function in ARED flow fetuses

The absence or reversal of end-diastolic flow in the umbilical artery (UA) is widely accepted as an ominous sign of fetal compromise. However, in these high-risk pregnancies, the significance of sequentially appearing changes of the venous return is poorly established. Doppler blood flow waveforms were longitudinally assessed in the inferior vena cava (IVC), ductus venosus (DV), umbilical vein (UV) and tricuspid valve, along with the UA, middle cerebral artery and descending aorta. Thirty-two serial Doppler studies were performed in six fetuses with intrauterine growth-retardation (IUGR). In the cases of absent or reversed UA endodiastolic flow, changes in the venous return were found following the same sequence: presence of dicrote pulsations in the UV, increase of retrograde flow in the IVC and reduction or inversion of DV velocity during atrial contraction. Transtricuspid flow patterns changed from normal to a restrictive pattern of ventricular filling. There were two intrauterine deaths and one early neonatal death. Our preliminary results suggest that the evaluation of the venous compartment of hemodynamically disturbed preterms fetuses along with right ventricular filling appears to be a useful model for investigating the physiopathology of fetal deterioration and, therefore, may yield indirect discriminatory signs of severe compromise.

Outcome of 88 pregnancies with absent or reversed end-diastolic blood flow (ARED flow) in the umbilical arteries

OBJECTIVES

To investigate both perinatal and postneonatal morbidity and mortality in fetuses with absent or reversed end-diastolic flow (ARED flow) in the umbilical artery.

STUDY DESIGN

A 5 year prospective follow-up of 88 fetuses with ARED flow.

RESULTS

Sixteen stillbirths, 16 neonatal deaths, six postneonatal deaths and one death at 2 years of age were noted. Out of the 42 fetuses born alive, 36 showed a normal neurological development whereas six were mentally handicapped. Adverse prognosis was more frequently found in the group with absent end-diastolic flow at first examination and then reversed flow until delivery, compared to the groups of always absent or always reversed end-diastolic flows.

CONCLUSIONS

Prompt delivery is recommended in these high-risk pregnancies in order to prevent long-term sequelae, obviously depending on the local limits of viability. Further studies appropriately designed for assessing long-term neurodevelopment of fetuses with ARED flow, although demanding, are mandatory.

Comparison of three ELISA tests for seroepidemiology of bovine fascioliosis

The aim of the present study was to compare the sensitivity, specificity and usefulness of the DIG-ELISA, DOT-ELISA and Indirect ELISA tests for determining the seroprevalence of fasciolosis in cattle under tropical conditions in Mexico. To standardize the tests, positive and negative sera to F. hepatica from 88 Holstein Freisian adult cows located in an enzootic area of fascioliosis and 88 crossbred adult cattle from a fluke-free area were used. For the epidemiological study, 85 crossbred cattle between 1 to 7 years of age were used. Animals were bled every two months, from March 1995 to September 1996 and the sera obtained were stored at -70 degrees C, until used. Indirect ELISA showed a sensitivity of 96.5% and a specificity of 98.8%, DIG-ELISA 97.5% and 80.0% and DOT-ELISA 93.1% and 95.4%, respectively. During 1995, Indirect ELISA yielded the highest levels of IgG anti-F. hepatica antibodies. However, in 1996, after animal treatment with triclabendazole, DIG-ELISA tended to show higher percentages of antibody-positive animals, but it was not significantly different (p>0.05) from the other tests. Comparisons made in parallel to the faecal sedimentation test demonstrated that all serological tests detected higher percentages of positive animals. Only one serum out of ten (10%) of Paramphistomum spp. cross-reacted with the DOT-ELISA test, but no cross-reaction was observed with sera from animals with other parasites. All ELISA tests were highly sensitive and specific; they may be recommended for use in seroepidemiological surveys for F. hepatica.

Variation of embryonic/fetal heart rate at 6-13 weeks' gestation

The aim of this study was to investigate changes in heart rate, namely the intraindividual variation, in normal embryos/fetuses between 6 and 13 weeks' gestation. A prospective study was performed of 41 singleton pregnancies undergoing routine ultrasound examination during the first trimester of pregnancy. For each case, the embryonic/fetal heart rate was measured on three consecutive occasions with a mean interval of 4 min. The difference in heart rate values between the serial measurements varied from 0 to 18 beats/min and was significantly associated with gestational age (Spearman r = 0.26, p < 0.01). In the group of 15 fetuses (examined before 10 weeks' gestation), the difference between measurements (median = 0 beats/min, range 0-8 beats/min) was significantly lower (z = 2.48, p < 0.05) than in fetuses assessed after 10 weeks of gestation (median = 3, range 0-18 beats/min). Reliable and reproducible information concerning embryonic/fetal heart rate may be obtained from a single measurement, especially when pregnancies are examined before 10 weeks of gestation.

Anomalous fetal venous return associated with major chromosomopathies in the late first trimester of pregnancy

We report three cases of increased nuchal translucency at 12-13 weeks of gestation in three fetuses with trisomies 13, 18 and 21. All three fetuses were associated with anomalous venous return evaluated by Doppler ultrasonography. Complete pathological examination was performed following termination in each case. We suggest that alterations in the venous compartment can be an early sign of poor outcome and should prompt a detailed search for cardiac defects early in gestation.

Early antenatal diagnosis of cardiac defects using transvaginal Doppler ultrasound: new perspectives?

OBJECTIVE

Cardiac defects are the most prevalent congenital anomalies. Screening policies have adopted an 18- to 22-week ultrasound scan to detect such anomalies. However, diagnosis may be feasible early in pregnancy using transvaginal Doppler ultrasound.

METHODS

Transvaginal ultrasound, including nuchal translucency (NT) measurement, is routinely performed at 10-13 weeks of gestation at our department. Complementary arterial and venous blood flow Doppler evaluation is also performed in cases of increased NT as a part of an ongoing research project.

RESULTS

Ultrasound revealed complete atrioventricular septal defects in 2 trisomic fetuses (trisomy 18 and 21) at 12 and 13 weeks of gestation, respectively, with increased NT and abnormal venous blood flow velocity.

CONCLUSIONS

Increased NT has been associated with major chromosomal anomalies and is being increasingly related to cardiac defects. Considering that venous blood flow patterns may provide additional clues to the cardiac function, it may be useful as a complementary tool for the earlier diagnosis of structural cardiac anomalies.

Semiautomated ultrasonographic measurement of fetal nuchal translucency using a computer software tool

Nuchal translucency (NT) thickness measurement has been recently proposed as a part of routine ultrasound scanning during the late first trimester of pregnancy, for the early screening of chromosomal abnormalities. Manual determination of NT is currently performed using electronic calipers placed by the operator in the middle of two echogenic lines displayed on the screen. Therefore, intraobserver and interobserver repeatability can be questioned. This paper presents a software tool that has been developed for achieving this goal in a semiautomatic way, improving the reproducibility of the method.

Dyssegmental dysplasia: a case report of a Rolland-Desbuquois type

Two different forms of dyssegmental dysplasia, mild and severe, can be distinguished on clinical, radiographic and chondro-osseous morphologic grounds. The milder Rolland-Desbuquois type is frequently characterised by survival beyond the newborn period. The lethal Silverman-Handmaker type has distinctive and more severe findings. In this paper, a rare case of the Rolland-Desbuquois type is presented. The case is unusual because although it was the milder form, the child died on the 10th day of life.

Increased fetal nuchal translucency: possible involvement of early cardiac failure

The ultrasonographic measurement of nuchal translucency thickness at 10-13 weeks of gestation is accepted as an efficient method of screening for chromosomal abnormalities. However, the underlying mechanism producing increased nuchal translucency thickness is still poorly understood. The purpose of this study was to investigate the possible contribution of impaired cardiac function to such an increase, by studying the venous return in the ductus venosus, using Doppler ultrasound. In a total of 65 fetuses, nuchal translucency thickness was measured at 10-13 weeks of gestation by means of a transvaginal probe. Color-coded and pulsed Doppler ultrasound were also used to evaluate different hemodynamic parameters in the ductus venosus: maximum systolic and diastolic velocities, pulsatility index, lowest forward velocity during atrial contraction and fetal heart rate. Fetal nuchal translucency thickness of > or = 3 mm was found in 17 cases; in five of them there were chromosomal anomalies: four trisomy 21 and one trisomy 18. Of interest is the finding that in the five chromosomally abnormal fetuses with increased nuchal translucency thickness, the forward velocity during atrial contraction was consistently less than 2 cm/s (p < 0.001). This impairment of atrial contraction may well implicate cardiac failure and/or heart defects in the pathogenesis of increased nuchal translucency thickness in the first trimester of pregnancy. Furthermore, nuchal translucency may prove to be a sensitive marker for the early identification of fetal cardiac anomalies.

Prenatal diagnosis of partial trisomy 2q. Case report

A case of partial trisomy 2(q21q33) detected by cordocentesis at 27 weeks' gestation in a polymalformed fetus is described. This is the second case of a prenatally detected de novo duplication of 2q and the first involving the region referred to above.

Ductus venosus revisited: a Doppler blood flow evaluation in the first trimester of pregnancy

The functional role of the fetal ductus venosus (DV) is still poorly established. Few reports are available in the literature concerning assessment of fetal venous return during the late first trimester of pregnancy. Our objective was to determine the normal Doppler blood velocity waveform in the human fetal DV as early as 10-13 weeks gestation. Adopting strict methodological concerns, 61 Doppler blood flow evaluations of the DV considered technically acceptable were selected. Using transvaginal Doppler ultrasound, several DV haemodynamic parameters were assessed: peak systolic and diastolic velocities, time-averaged velocity, maximum velocity during atrial contraction, pulsatility index and fetal heart rate (FHR). Except for the FHR, no significant variations were observed for the above mentioned parameters during this period, and no correlation could be established between FHR and the different flow velocity parameters. Further knowledge about DV haemodynamics in the early phases of pregnancy may make a valuable contribution to the understanding of fetal venus return to the heart and cardiac function.

Fetal heart rate in trisomy 21 and other chromosomal abnormalities at 10-14 weeks of gestation

Fetal heart rate was measured routinely as part of a prospective study examining the efficacy of screening for trisomy 21 by fetal nuchal translucency thickness and maternal age. In 6903 normal singleton pregnancies the fetal heart rate decreased from a mean of 171 bpm at 10 weeks of gestation to 156 bpm at 14 weeks (r = 0.413, p < 0.0001). In 85 trisomy 21 pregnancies, the mean heart rate was significantly higher than in the normal group (mean difference 0.67 SD, 95% confidence interval 0.42-0.92, t = 5.3, p < 0.001). The fetal heart rate in trisomy 18 and triploid fetuses was significantly lower and in trisomy 13 and Turner syndrome was higher than normal. There was no significant association between delta fetal heart rate and delta nuchal translucency thickness in either the normal (r = -0.018) or the trisomy 21 (r = -0.031) pregnancies. Consequently, the risk for chromosomal defects can be derived by combining data from maternal age, fetal nuchal translucency and fetal heart rate. The effectiveness of screening by this method was examined in a self-selected population with completed pregnancies that had undergone first-trimester scanning. This population contained 6903 normal and 29 trisomy 21 fetuses. For a false-positive rate of about 5%, the sensitivity for trisomy 21 was 48% by maternal age, 26% by fetal heart rate, 72% by nuchal translucency thickness, 59% by maternal age and fetal heart rate, 76% by maternal age and nuchal translucency thickness and 83% by a combination of maternal age, nuchal translucency thickness and fetal heart rate.

[Pattern of intrauterine growth and Doppler flowmetry]

The aim of this study was to evaluate the accuracy of ultrasound biometric and hemodynamic fetal parameters for the prenatal diagnosis of intrauterine retardation in a sample of 438 pregnant women who had their first visit before the 16th week of gestation at the outpatient clinic of the Department of Obstetrics and Gynecology, S. Joào Hospital. The results are presented for 427 mother-infant pairs corresponding to singleton pregnancies uncomplicated by congenital malformations. The prevalence of SGA was 4.9%, 86.2% for AGA and 8.9% for LGA. A relatively low sensitivity and high specificity were calculated for the ultrasound parameters evaluated, as observed in previous studies performed in other populations. Mean values for the differences of umbilical vessels resistance index measured at 28-32 and 35-37 gestation weeks were significantly lower in SGA newborns, probably reflecting a sustained compromise of vascular compliance (umbilical/placental). The observed lack of agreement between the pre and the postnatal diagnosis of SGA emphasises the need to define local reference birthweight curves or the careful adoption of European standards obtained in populations identical to our.

Monitoring of cardiac-extracardiac haemodynamics and automated fetal heart rate preceding intrauterine death

A severely growth-retarded fetus was monitored longitudinally for haemodynamic profiles and automated cardiotocogram analysis in the 30 days preceding death. Initially a pattern of hypoxia and moderately deteriorated cardiac function was detected. Later on, signs of progressive heart failure developed, in conjunction with deteriorating fetal heart rate patterns.

Reverse end-diastolic umbilical artery blood flow at 11 weeks' gestation

This report describes a case of reverse end-diastolic blood flow in the umbilical artery of one of the fetuses of a twin pregnancy at 11 weeks' gestation. Cytogenetic studies after amniocentesis performed at 12 weeks revealed a 45.X karyotype of this twin whose death was registered 1 week later. Spontaneous delivery of the co-twin occurred at 37 weeks; the newborn was healthy and normal. This is the earliest record of reverse diastolic flow in the umbilical artery. Even in the first trimester of pregnancy this is an ominous sign and fatal demise is expected.

Clinical significance of absent or reversed end diastolic velocity waveforms in umbilical artery

Doppler ultrasound provides a non invasive method to assess fetal haemodynamics. We looked at the outcome of doppler velocimetry of the umbilical artery in three groups of pregnancies: those with positive end diastolic velocities (PED; n = 214), absent end diastolic velocities (AED; n = 178) and reversed end diastolic velocities (RED; n = 67). We collected our data from 9 European centers. Logistic regression showed that compared with pregnancies with hypertension only, pregnancies complicated by intra uterine growth retardation (IUGR) had a higher risk of developing absent or reversed end diastolic velocity waveforms (ARED) flow. ARED flow in the umbilical artery (odds ratio: OR = 3.1). Pregnancies complicated by both IUGR and hypertension had an even higher risk (OR = 7.4). Maternal age and smoking habits did not influence the risk of developing ARED flow. The overall perinatal mortality rate was 28%. Significantly more neonates in the ARED flow group needed admittance to the neonatal intensive care unit (PED group 60%, AED group 96%, RED group 98%). The OR for perinatal mortality in pregnancies complicated by AED flow was 4.0 and in RED flow was 10.6, compared with PED flow, even after adjustment for menstrual age. ARED flow in the umbilical artery did not influence the risk of respiratory distress syndrome or necrotising enterocolitis of the neonate, but ARED flow significantly influenced the risk of cerebral haemorrhage, anaemia, or hypoglycaemia. We advise that pregnancies complicated by IUGR and/or hypertension should be followed up with doppler velocimetry to trace utero-placental problems as early as possible. A caesarean section is recommended in all pregnancies complicated by ARED flow if the gestational age and predicted neonatal weight can be handled by the local neonatal intensive care unit.

[Transvaginal endosonography and Doppler study in embryo-fetal hemodynamic assessment in the first pregnancy trimester]

Transvaginal endosonography is now currently used in obstetrics and gynecology practice and seems a promising tool for essential studies on first trimester pregnancy. High-resolution and duplex/color Doppler in vaginal probes have brought to light new chances for early investigations on embryonic-fetal haemodynamics. We report our experience in this field, together with a review of the literature, giving an overview on embryonic-fetal cardiovascular haemodynamics studied by this approach. Blood flow patterns of intracardiac flows as extra-cardiac circulation during first trimester pregnancy are reported.