Reference ranges for two-dimensional echocardiographic examination of the fetal ductus arteriosus

Ductus Arteriosus in Fetal and Perinatal Life

The ductus arteriosus represents an essential vascular structure connecting the pulmonary artery and the aorta. Over the past decades, there has been substantial advancement in our understanding of both the fundamental and clinical aspects of the ductus arteriosus. In particular, the clarification of the regulatory mechanisms governing ductal patency in critical stages such as the fetal and the perinatal period has enabled optimal management of both physiological and pathological conditions in which the ductus arteriosus plays a crucial role. Furthermore, a more in-depth understanding of the regulatory mechanisms controlling this fundamental structure has facilitated the development of advanced therapeutic strategies and personalized interventions. In the present review, we provide a comprehensive overview of the ductus arteriosus during fetal and perinatal life, encompassing its physiological functions, pathological conditions, and clinical implications. Through this examination, we aim to contribute to a broader understanding of the ductus arteriosus' role in these critical developmental stages and its significance in clinical practice.

Cardiac Function Assessment in Fetuses With Ductus Arteriosus Constriction: A Two-Dimensional Echocardiography and FetalHQ Study

Background

Fetal ductal constriction (DC) is associated with excessive polyphenol-rich food (PRF) consumption during pregnancy. However, the effect of this hemodynamic change on fetal cardiac function still needs to be elucidated. Therefore, this study aimed to evaluate the cardiac function of fetuses with PRF-related DC and to describe serial observations of cardiac function changes.

Methods

We compared the traditional echocardiographic indices, including morphological, hemodynamic, and functional parameters, between study fetuses and controls. For global and segmental deformation analysis of the left and right ventricles, fetalHQ with the speckle-tracking technique was used to calculate sphericity index (SI), global longitudinal strain (GLS), fractional shortening (FS), fractional area change (FAC), etc. In addition, follow-up data were compared with the generalized linear model.

Results

A total of 60 DC fetuses and 60 gestational-matched controls were enrolled in our study, with 20 DC fetuses undertaking a follow-up echocardiogram after 2–3 weeks. Compared with controls, there was a distinct decrease in right ventricular GLS (RVGLS) (−13.39 ± 3.77 vs. −21.59 ± 2.51, p < 0.001), RVFAC (22.20 ± 9.56 vs. 36.01 ± 4.84, p < 0.001), left ventricular GLS (LVGLS) (−19.52 ± 3.24 vs. −23.81 ± 2.01 p < 0.001), and LVFAC (39.64 ± 7.32 vs. 44.89 ± 4.91, p = 0.004). For 24-segment FS analysis, DC fetuses showed lower FS in left ventricular (LV) segments 18–24, with no difference in LV segments 1–17. Right ventricular (RV) FS in segments 4–23 was also reduced in the DC group. The 24-segment SI analysis indicated significantly lower SI in DC than those in controls for LV segments 1–14 and RV segments 19–24. We found that the pulsatility index (PI) of ductus arteriosus (DA) was an independent variable for RVGLS (β = −0.29, p = 0.04). In 20 DC fetuses with follow-up echocardiograms, no obvious difference in myocardial deformation was found between the initial examination and follow-up data.

Conclusion

Left and right ventricular performances were both impaired in DC fetuses, along with a series of morphological and hemodynamic changes. Although the state of DA constriction improved on second examinations, cardiac function was not completely restored.

Aneurysms of the fetal arterial duct are usually benign

INTRODUCTION

Fetal arterial duct aneurysm, saccular, or fusiform enlargement of the arterial duct affect > 8% of pregnancies. It is uncommonly associated with serious sequelae postnatally, including thromboembolic events such as stroke and left pulmonary artery obstruction, rupture with demise, and vocal cord compression. Risk factors include maternal diabetes, late maternal age, maternal blood type A, large size for gestational age, and connective tissue disorders. The clinical importance remains unknown, making it difficult to determine how to monitor this finding postnatally.

METHODS

This is a retrospective echocardiogram study assessing the outcomes of fetally diagnosed arterial duct aneurysm. Images and records were reviewed to confirm the diagnosis and assess risk factors and outcomes. Descriptive statistics were performed.

RESULTS

Fifty-three affected fetuses were identified. The median gestational age at diagnosis was 34.9 weeks (IQR 32.6, 36.6). The median maternal age was 31 years (IQR 27.3-34.1). Eight (15%) had maternal diabetes. The most common blood type was type O. The median maximal dimension of the aneurysm was 7.6 mm (IQR 6.1, 8.7). The aortic end was the maximal dimension in 67.9%. Median postnatal follow-up period was 76 days (IQR 7.5, 368). No patients sustained postnatal demise related to the duct, rupture of the ductal aneurysm, cerebral infarction, or other sequelae. No newborn had associated connective tissue disorders. No patients underwent ductal intervention.

CONCLUSION

In our experience, no adverse outcomes related to the ductal aneurysm were identified. This should be considered when counselling families about the need for postnatal follow-up.

Variations in ductus arteriosus Doppler parameters in different sonographic views during the second half of gestation

The aim of the present study was to compare the Doppler parameters of the fetal ductus arteriosus (DA) measured in the traditional longitudinal ductal arch (LDA) view and the newly introduced three vessels and trachea (3VT) plane of the fetal upper mediastinum. The peak systolic velocity (PSV), end-diastolic velocity (EDV), time-averaged maximum velocity (TAMXV) and velocity-time integral (VTI) measurements were taken for 52 fetuses with normal growth (including 29 females). The pulsatility index (PI) and resistance index (RI) were calculated. All parameters for each fetus were measured three times by the same sonographer in the LDA and the 3VT view, and the averages were taken to obtain the final value. Differences in the above values obtained from the LDA and 3VT views were analyzed and the correlation between the differences of all indices and the gestational age (GA) was evaluated using Pearson's linear coefficient of correlation. All of the values were characterized as normally distributed continuous variables by homogeneity of variance analysis. Slight increases in the PSV, EDV, TAMXV and VTI determined in the LDA view were identified compared with those in the 3VT view (P<0.05). Furthermore, these increases were identified to be independent of the GA (P>0.05). However, no significant differences in the impedance indices PI and RI were observed between the two sonographic planes (P>0.05). In conclusion, the LDA view provides a better chance than the 3VT view to obtain higher values of velocity parameters (PSV, EDV, TMAXV and VTI) within the fetal DA, and the differences are independent of the GA. However, no significant variations in the impedance indices PI and RI were observed between these two sonographic planes.

Are complicated monochorionic twins more susceptible to indomethacin-induced fetal ductal constriction? Two cases of laser surgery for Twin-Twin Transfusion syndrome

Indomethacin is a commonly used medication against preterm delivery. Several reports of fetal ductal constriction have been described after indomethacin use in the literature; however, there are no previously documented reports describing an association between Twin-Twin Transfusion syndrome and a constrictor effect of indomethacin on the ductus arteriosus. Two patients were referred to our department for Twin-Twin Transfusion syndrome and each underwent placental laser surgery. Constriction of the ductus arteriosus occurred as early as 20 and 24 weeks’ gestation following maternal use of indomethacin after laser surgery. Spontaneous amelioration was observed after discontinuation of the drug. The constrictor effect of indomethacin on the ductus arteriosus can be observed even after a single dose and as early as 20 weeks of gestation in complicated monochorionic twin pregnancies. We emphasize meticulous use of indomethacin in complicated monochorionic twin pregnancies because the constrictive effect seems to be independent of gestational age.

Ductus arteriosus and fetal echocardiography: Implications for practice

The ductus arteriosus (DA) is a crucial part of the fetal circulation, both in the normal fetus and in critical congenital heart disease (CHD). It allows shunting between the pulmonary and systemic circulations. In physiological prenatal conditions, the DA lets the majority of right ventricular output bypass the fluid-filled, high-resistance lungs. The DA can cause hemodynamic compromise in the fetus and neonate when constricted or absent (in isolation or in patients with CHD) and may lead to pre- or postnatal sequelae within other systems when forming part of a vascular ring. In CHD, the DA can be interrogated by fetal echocardiography to infer information regarding severity of pulmonary outflow tract obstruction, adequacy of the sub-pulmonary ventricle to supply pulmonary blood flow, and to predict the likelihood of atrial septum restriction in transposition of the great arteries. A good understanding of the DA is crucial for fetal cardiologists.

Dysfunction of the foetal arterial duct results in a wide spectrum of cardiovascular pathology

OBJECTIVE

Foetal ductal problems may have various cardiopulmonary consequences. This study aimed to identify the spectrum of ductus arteriosus (DA) dysfunction (closure, constriction, kinking, aneurysm and thrombosis) and the resultant clinical and echocardiographic presentation in foetuses and neonates.

METHODS AND RESULTS

This is a retrospective analysis of serial pre- and post-natal data of 27 cases of foetal ductal dysfunction diagnosed at a median gestational age of 33 weeks (range 20-39). The most common abnormalities observed were premature closure of the DA in 56% (15/27) and constriction in 29% (8/27). Right ventricular hypertrophy was present in 75% (n = 11/15) of foetuses with premature DA closure, while ventricular dilation (4/7, 57%) was a more common feature in foetuses with ductal constriction. After birth, 63% (17/27) of new borns presented with cyanosis and pulmonary hypertension that required active treatment. Three infants died after birth. Abnormalities resolved spontaneously after birth in about 50% of patients. In some children, pulmonary valve stenosis and regurgitation was progressive and required further treatment.

CONCLUSIONS

An abnormal right heart on foetal four-chamber ultrasound view should alert the sonographer to the possible presence of foetal ductal dysfunction. Ductal occlusion, transient or fixed constriction, kinking and aneurysm formation are associated with foetal cardiopulmonary sequelae. Symptoms and pathology is probably related to the type, foetal age, rapidity of progression and duration of intrauterine ductal dysfunction. Correspondingly, clinical outcomes vary ranging from little or no symptoms to severe respiratory distress and even foetal or neonatal death.

Prediction of sustained fetal toxicity induced by ketoprofen based on PK/PD analysis using human placental perfusion and rat toxicity data

AIM

We encountered a case of fetal toxicity due to ductus arteriosus (DA) constriction in a 36-week pregnant woman who had applied multiple ketoprofen patches. The aim of the present study was to present the case and develop a model to predict quantitatively the fetal toxicity risk of transdermal administration of ketoprofen.

METHODS

Human placenta perfusion studies were conducted to estimate transplacental pharmacokinetic (PK) parameters. Using a developed model and these parameters, human fetal plasma concentration profiles of ketoprofen administered to mothers were simulated. Using pregnant rats, DA constriction and fetal plasma drug concentration after ketoprofen administration were measured, fitted to an Emax model, and extrapolated to humans.

RESULTS

Transplacental transfer value at the steady state of ketoprofen was 4.82%, which was approximately half that of antipyrine (passive marker). The model and PK parameters predicted almost equivalent mother and fetus drug concentrations at steady state after transdermal ketoprofen administration in humans. Maximum DA constriction and maximum plasma concentration of ketoprofen after administration to rat dams were observed at different times: 4 h and 1 h, respectively. The model accurately described the delay in DA constriction with respect to the fetal ketoprofen concentration profile. The model with effect compartment and the obtained parameters predicted that use of multiple ketoprofen patches could potentially cause severe DA constriction in the human fetus, and that fetal toxicity might persist after ketoprofen discontinuation by the mother, as observed in our case.

CONCLUSION

The present approach successfully described the sustained fetal toxicity after discontinuing the transdermal administration of ketoprofen.

Late onset of large benign ductus arteriosus aneurysm presented with increased nuchal translucency and cystic hygroma at first trimester Down syndrome screening

OBJECTIVE

Fetal ductus arteriosus aneurysm (DAA) is a rare but potentially risky congenital heart disease. It is often not diagnosed until the third trimester because of its asymptomatic nature and late onset. In rare occasions, DAA may result in serious complications; therefore, prenatal diagnosis is helpful.

CASE REPORT

Herein, we report the case of a foetus with cystic hygroma and increased nuchal translucency in the first trimester (but regressed at 20-week anomalous scan). Karyotyping indicated a 46 XY genotype. A large vascular mass was noted at the apex of the left lung by Doppler ultrasound at 38 weeks of gestation, with a diameter of 12.5 mm. After birth, echocardiography showed a patent ductus arteriosus with aneurysmal dilatation (17 mm as the largest diameter); thus, DAA was impressed. Chest computed tomography and three-dimensional angiography confirmed the large aneurysmal dilatation of the ductus arteriosus with a closed end at the pulmonary arterial side.

CONCLUSION

The male infant survived, but presented mild respiratory distress at birth. He was discharged at 24 days of age. At that time, DAA had regressed partially (diameter of 8.5 mm and much less blood flow), and it fully regressed at 40 days of age.

Diagnostic ultrasound features and outcome of restrictive foramen ovale in fetuses with structurally normal hearts

Intrauterine foramen ovale (FO) restriction in association with congenital heart disease (CHD) carries a poor prognosis. However, in the absence of CHD, the clinical importance of restrictive FO in the fetus is not well understood. We evaluated the antenatal prevalence, clinical presentation, diagnostic ultrasound features, and outcome of restrictive FO in fetuses without CHD. We reviewed the echocardiographic and clinical records of 23 fetuses diagnosed with a restrictive FO and structurally normal heart between 2001 and 2012. The atrial septum, dimensions of cardiac structures, left and right cardiac output and Doppler interrogation of cardiac flows were examined. The clinical outcomes of all fetuses with restrictive FO were analysed. Restrictive FO was identified in 23 of 1,682 (1.4%) fetuses with no CHD. Enlarged right heart structures (100%), hypermobile or redundant primum atrial septum (91%), increased right-to-left ventricular cardiac output ratio (91%), and posteriorly angulated ductus arteriosus (68%) were the most common echocardiographic findings associated with this rare phenomenon. Additional noncardiac systemic abnormalities were identified in 13 (56%) babies. Seven (30%) neonates developed persistent pulmonary hypertension, and 7 infants died. Antenatal restrictive FO is an underrecognised entity despite being a common cause of right heart dilatation in the fetus. In the absence of CHD, restrictive FO is well tolerated antenatally, but its frequent association with noncardiac abnormalities and pulmonary hypertension in the neonate are noteworthy.

Prenatal effects of maternal consumption of polyphenol-rich foods in late pregnancy upon fetal ductus arteriosus

Fetal circulation has characteristic features, being morphologically and functionally different from extrauterine circulation. The ductus arteriosus plays a fundamental role in directing the blood flow to fetal inferior body parts. Basically, the ductus arteriosus directs 80-85% of the right ventricular output arising from the superior vena cava, coronary sinus, and a small part from the inferior vena cava to descending aorta. Its histological structure is made up predominantly by a thick muscular layer, differently from the aorta and the pulmonary artery, which increases with gestational age. The fibers have a circumferential orientation, especially at the external layers, facilitating and making effective ductal constriction. These factors may generate lumen alterations which may cause fetal and neonatal complications, such as heart failure, hydrops, neonatal pulmonary hypertension, and even death. Classically, maternal administration of indomethacin and/or other antiinflammatory drugs interfere in prostaglandins metabolism, causing ductal constriction. However, many cases of fetal ductal constriction, as well as of persistent neonatal pulmonary artery hypertension, remain without an established etiology, being referred as "idiopathic." In recent years, a growing body of evidence has shown that herbs, fruits, nuts, and a wide diversity of substances commonly used in daily diets have definitive effects upon the metabolic pathway of inflammation, with consequent inhibition of prostaglandins synthesis. This antiinflammatory action, especially of polyphenols, when ingested during the third trimester of pregnancy, may influence the dynamics of fetal ductus arteriosus flow. The goal of this review is to present these new observations and findings, which may influence dietary orientation during pregnancy.

Reference ranges of ductus arteriosus derived by cardio-spatiotemporal image correlation from 14 to 40 weeks of gestation

OBJECTIVE

To construct reference ranges of fetal ductus arteriosus (DA) derived by volume datasets of cardio-spatiotemporal image correlation (cardio-STIC).

METHODS

Cardio-STIC volume datasets were acquired from low-risk singleton pregnancies with a reliable gestational age from 14 to 40 weeks. In offline analysis with 4D View version 9, fetal DA was measured in the transverse ductal arch view with orthogonal control in the multiplanar view. The reference ranges of the DA and Z-score equation were constructed against gestational weeks and biparietal diameter (BPD) as independent variables.

RESULTS

A total of satisfactory 606 volumes were analyzed. The reference ranges for predicting means and SDs of fetal DA were constructed based on the best-fit regression model. Mean DA (mm) was best predicted by linear model as a function of GA (weeks) and BPD (cm) as follows: Predicted DA diameter (cm) = -0.051 + 0.014 × GA (weeks) (r = 0.84) and Predicted DA diameter (cm) = -0.015 + 0.053 × BPD (cm) (r = 0.83). Models for Z-score calculation and centile charts for predicting fetal DA were also provided.

CONCLUSION

Reference ranges of the fetal DA and Z-score model are provided. These may serve as a useful tool in the assessment of fetal DA, especially in fetal cardiac anomalies or in monitoring fetuses exposed to maternal indomethacin.

Idiopathic occlusion of the fetal ductus arteriosus without lumen narrowing

Constriction of the fetal ductus arteriosus in utero can be caused by pharmacological agents or can occur spontaneously. The spontaneous constriction and closure of the ductus arteriosus have been reported sporadically in the previous literature, either completely obliterated or constricted ductus arteriosus causing narrowing. This cardiac defect was characterized by no blood flow through the ductus arteriosus without lumen narrowing. The fetal echocardiography revealed the features of premature closure of the ductus arteriosus. We report a case of occlusion of the ductus arteriosus at 38 weeks of gestation that had a favorable postnatal outcome after immediate cesarean section.

Shepherd Hook Anomaly of Ductus Arteriosus With Sudden Intrapartum Fetal Demise: Two Case Reports

Patency of the ductus arteriosus is critical in maintaining fetal circulation, and premature closure is associated with fetal and early neonatal death. We present 2 cases of sudden demise in the delivery room associated with atypical ductal anatomy with obstruction due to kinking and intraluminal intimal ridges. Shepherd hook anomaly of the ductus arteriosus may represent a new congenital heart lesion associated with poor fetal outcome.

In vitro hemodynamic investigation of the embryonic aortic arch at late gestation

This study focuses on the dynamic flow through the fetal aortic arch driven by the concurrent action of right and left ventricles. We created a parametric pulsatile computational fluid dynamics (CFD) model of the fetal aortic junction with physiologic vessel geometries. To gain a better biophysical understanding, an in vitro experimental fetal flow loop for flow visualization was constructed for identical CFD conditions. CFD and in vitro experimental results were comparable. Swirling flow during the acceleration phase of the cardiac cycle and unidirectional flow following mid-deceleration phase were observed in pulmonary arteries (PA), head-neck vessels, and descending aorta. Right-to-left (oxygenated) blood flowed through the ductus arteriosus (DA) posterior relative to the antegrade left ventricular outflow tract (LVOT) stream and resembled jet flow. LVOT and right ventricular outflow tract flow mixing had not completed until approximately 3.5 descending aorta diameters downstream of the DA insertion into the aortic arch. Normal arch model flow patterns were then compared to flow patterns of four common congenital heart malformations that include aortic arch anomalies. Weak oscillatory reversing flow through the DA junction was observed only for the Tetralogy of Fallot configuration. PA and hypoplastic left heart syndrome configurations demonstrated complex, abnormal flow patterns in the PAs and head-neck vessels. Aortic coarctation resulted in large-scale recirculating flow in the aortic arch proximal to the DA. Intravascular flow patterns spatially correlated with abnormal vascular structures consistent with the paradigm that abnormal intravascular flow patterns associated with congenital heart disease influence vascular growth and function.

Development of Z-scores for fetal cardiac dimensions from echocardiography

OBJECTIVES

Z-scores for cardiac dimensions are well established in postnatal life, but have yet to be developed for fetal cardiac dimensions. These would be of real advantage to the clinician in accurately quantifying size and growth of cardiac dimensions and to the researcher by allowing mathematical comparison of growth in differing subgroups of a disease. The purpose of this observational study, conducted at tertiary fetal medicine and cardiology units, was to produce formulae and nomograms allowing computation of Z-scores for fetal cardiac dimensions from knowledge of femur length (FL), biparietal diameter (BPD) or gestational age (GA) using fetal echocardiography.

METHODS

Seventeen fetal cardiac dimensions were measured in 130 pregnant women with singleton fetuses of gestational age 15-39 weeks. Regression equations were derived relating all dimensions to FL, BPD and GA. From the calculations, formulae were then developed allowing fetal cardiac Z-score computation.

RESULTS

The relationships between cardiac dimensions and FL, BPD or GA were described following natural log transformation. From this analysis, FL (taken as an expression of fetal size) had the highest correlation to fetal cardiac dimensions. From the developed nomograms, Z-scores of specific fetal cardiac structures could be estimated from knowledge of the FL, BPD or GA and echocardiographically derived measurements.

CONCLUSIONS

This study allowed computation of Z-scores in fetal life for 17 cardiac dimensions from FL, BPD or GA. Previous studies of normal data allowed qualitative assessment of where abnormal cardiac dimensions lay with regard to the normal range. Z-scores from this study allow quantitative analysis of where such dimensions lie relative to the mean. This permits exact assessment of growth of fetal cardiac structures in normal hearts and particularly in congenitally abnormal hearts where quantitative assessment of the growth of cardiac structures is important in analyzing and planning treatment strategies.

Fetal echocardiographic diagnosis of isolated ductus arteriosus aneurysm: a longitudinal study from 32 weeks of gestation to term

OBJECTIVE

To investigate the echocardiographic characteristics of isolated fetal ductus arteriosus aneurysm (DAA) and the factors influencing its development.

METHODS

Fetal echocardiograms for 509 low-risk singleton pregnancies were performed longitudinally from 32 weeks of gestation. The ventricular outflow tracts and great vessels were visualized, focusing on changes in the ductus arteriosus (DA), and fetuses with DAA or ductus arteriosus dilatation (DAD) were identified. Prenatal and perinatal findings were compared between those infants diagnosed postnatally with and those without neonatal DAA.

RESULTS

Forty-one of the 509 fetuses (8.1%) studied had neonatal DAA; 2.2% (11/509) had DAA and 5.9% (30/509) DAD before delivery. The mean gestational age at the time of diagnosis of fetal DAA/DAD was 36.9 +/- 1.7 weeks. The mean maximal internal diameter of DAA/DAD was 8.0 +/- 0.8 mm at initial diagnosis, increasing to 10.8 +/- 1.6 mm before delivery. All cases originated from the aortic end of the DA. Compared with fetuses without neonatal DAA, the affected cases had a markedly more curved DA prior to diagnosis, and higher peak velocities at the aortic end of the DA (P < 0.05). Newborns with fetal DAA/DAD had a larger placental weight to birth body weight (BBW) ratio and were less likely to have a BBW appropriate for gestational age (P < 0.05). All cases of fetal DAA/DAD regressed spontaneously.

CONCLUSION

Isolated neonatal DAA is a continuity of fetal DAA/DAD. The development of fetal DAA/DAD is likely to be related to the higher peak velocities in the more markedly curved DA occurring in the latter part of the third trimester. Fetal DAA/DAD usually initiates at the aortic end of the DA, followed by progression towards the pulmonary end.