This study aimed to identify fetal echocardiographic measures that can accurately predict postnatal coarctation of the aorta (CoA). The study retrospectively reviewed 13 cases of prenatal CoA diagnosis confirmed postnatally, 14 cases of prenatal CoA diagnosis with normal postnatal arches, and 30 controls. Measurements of the aorta, head vessels, and ventricles were made on available fetal echocardiograms. Linear mixed effects models found significant differences in the true CoA group for smaller distal transverse arch diameter, smaller distal transverse arch to head vessel index, and longer head vessel distances. The head vessel to arch index trend also differentiated true CoAs from false positives. Fetal echocardiographic

1. Vol.:(0123456789)1 3
Pediatric Cardiology
https://doi.org/10.1007/s00246-018-2040-3
ORIGINAL ARTICLE
Fetal Echocardiographic Measures to Improve the Prenatal Diagnosis
of Coarctation of the Aorta
Chandni Patel1
· Bevin Weeks2
· Joshua Copel3
· John Fahey1
· Xuemei Song4
· Veronika Shabanova5
·
Dina J. Ferdman1
Received: 6 August 2018 / Accepted: 6 December 2018
© Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract
The objective of this study is to identify fetal echocardiographic measures that predict postnatal coarctation of the aorta
(CoA). A retrospective review of patients from 2013 to 2017 identified 13 cases of prenatal diagnosis of CoA confirmed
postnatally and 14 cases of prenatal diagnosis of CoA with normal arches postnatally. There were 30 controls. Measurements
were made and indices applied on all available longitudinal fetal echocardiograms for each patient. Linear mixed effects mod-
els were used to examine the between-group differences in the trajectories of the measurements. Significant differences were
seen in the true CoA group for the following: smaller distal transverse arch diameter to distance between the left common
carotid and left subclavian arteries (DT/LCA–LSCA) index (p = 0.04), smaller distal transverse arch diameter (p = 0.005),
and longer brachiocephalic to left common carotid artery (LCA) (p = 0.004) and LCA–left subclavian artery (LSCA) dis-
tances (p < 0.0001). Additionally, the LCA/DT index trend appears to differentiate false positives from true coarctations
(p < 0.03). The fetal echocardiographic DT/LCA–LSCA index, brachiocephalic–LCA distance and LCA–LSCA distance are
significant predictors of postnatal coarctation. The LCA/DT index trend over time may differentiate which of those patients
with prenatal concern for coarctation are more likely to develop coarctation postnatally. The use of fetal echocardiographic
measures may improve prenatal detection and predication of postnatal coarctation.
Keywords Fetal coarctation · Prenatal diagnosis · Fetal echocardiography
Introduction
Coarctation of the aorta (CoA) is a relatively common
congenital heart defect, accounting for 5–8% of defects [1,
2]. Many cases go undetected in the early postnatal period
and, in patients with severe coarctation, may present with
shock and cardiovascular collapse. Fetal diagnosis can aid in
appropriate post-natal monitoring, including prompt initia-
tion of prostaglandin to maintain patency of the ductus arte-
riosus, prevention of hemodynamic collapse, pre-operative
stability and risk reduction of neurovascular consequences
[3].
Current fetal parameters for identifying coarctation
include ventricular size discrepancy, disproportion in size
of the great vessels, presence of a posterior shelf, hypoplas-
tic aortic arch and/or isthmus, isthmic flow disturbance, low
ratio of isthmus to ductal diameter, persistence of the left
superior vena cava or the presence of a bicuspid aortic valve
[4, 5]. These markers, however, are non-specific and carry
a high false positive rate [6, 7]. This can lead to increased
parental anxiety and prolonged hospitalizations due to a
“watching and waiting” period to make the diagnosis of
coarctation as the ductus arteriosus closes [8].
Several neonatal studies to help diagnose coarctation in
the presence of a patent ductus arteriosus have focused on
head vessel anatomy and size, identifying echocardiographic
* Chandni Patel
Chandni320@gmail.com
1
Department of Pediatrics, Pediatric Cardiology, Yale
School of Medicine, 333 Cedar St, LLCI 302, New Haven,
CT 06510, USA
2
Congenital Heart Center, University of FL Health,
Gainesville, FL, USA
3
Maternal Fetal Medicine, Department of Obstetrics
and Gynecology, Yale School of Medicine, New Haven, CT,
USA
4
Yale School of Public Health, New Haven, CT, USA
5
Department of Pediatrics, Yale University, New Haven, CT,
USA

2. Pediatric Cardiology
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indices such as the carotid-subclavian index, isthmus to
descending aorta index and carotid to distal transverse arch
index [1, 2, 8–12]. These postnatal indices have not been
evaluated prenatally. We postulate that the abnormal propor-
tions of the aorta seen in these postnatal studies are present
prenatally, and that these postnatal indices can be applied
to fetal echocardiograms to accurately predict a diagnosis
of coarctation. The primary aim of this study is to identify
fetal echocardiographic measures that can provide an early
and accurate diagnosis of coarctation.
Methods
Study Population
Approval for this retrospective review study was obtained
from our institutional review board. Our surgical and fetal
databases at Yale New Haven Hospital were searched for
patients with either a prenatal or postnatal diagnosis of CoA
between January 2013 and July 2017. All infants who had
a fetal echocardiogram with a prenatal diagnosis of coarc-
tation and a postnatal echocardiogram either confirming
or refuting the diagnosis were included. Exclusion crite-
ria included unavailable post-natal follow-up and complex
congenital heart disease, including interrupted aortic arch
and hypoplastic left heart syndrome. The control group was
drawn from patients with a diagnosis of a small muscular
ventricular septal defect on fetal echocardiogram, in whom
there was no concern for CoA, and who had a complete post-
natal echocardiogram. We defined true CoA cases as patients
in whom a fetal diagnosis of coarctation was confirmed on
postnatal imaging, false positives as patients with an abnor-
mal fetal echocardiogram concerning for coarctation with a
normal arch postnatally, and control patients with muscular
VSDs and normal arches on pre- and postnatal imaging.
Medical Chart Review
Medical chart review on all patients was conducted and the
following demographics collected: gestational age (GA) at
time of each fetal echocardiogram, gender, race, indication
for fetal echocardiogram, results of any genetic testing, car-
diac and non-cardiac co-morbidities, type of delivery, age
at diagnosis of coarctation postnatally, GA at birth, birth
weight, and birth length. Clinical data from the post-natal
course were also collected for each patient and included
abnormal femoral pulses, presence of a blood pressure
gradient (a right arm blood pressure greater than a lower
extremity blood pressure by at least 10 mmHg), presence
of a significant pre- and post-ductal saturation differential
(≥ 10% difference between the right hand and a foot), need
for prostaglandins, days spent on prostaglandins, surgical
intervention, and time spent hospitalized “watching and
waiting” for the ductus arteriosus to close.
Fetal Echocardiographic Measurements
All pregnant mothers underwent standard two-dimensional,
color Doppler and spectral Doppler studies utilizing Philips
IE33 ultrasound machines (Andover, MA). Images were
reviewed and measurements made on either the Yale PACS
system or a Lumedx echo reading station (Oakland, CA).
Longitudinal fetal echocardiographic studies were reviewed
and retrospective measurements were made on all available
fetal echocardiograms for each patient, including (Fig. 1):
diameters of the ascending aorta at the level of the right pul-
monary artery, proximal transverse arch at the origin of the
left carotid artery, distal transverse arch at the origin of the
left subclavian artery (LSCA), aortic isthmus, left common
carotid artery (LCA) at its origin from the arch; maximum
diameters of the left ventricle and right ventricle; and dis-
tances between the brachiocephalic to LCA (BC–LCA) and
the LCA to LSCA (LCA–LSCA). The following previously
studied postnatal indices were applied to our fetal echocardi-
ograms: LCA to distal transverse arch diameters (LCA/DT)
[8, 13, 23], distal transverse arch diameter to LCA–LSCA
distance (DT/LCA–LSCA) [2, 8, 11, 22], and left ventricle
to right ventricle diameters [6, 14]. These measurements
were novel to our lab and were not part of our fetal protocol
prior to this study. 2D echocardiographic still-frames of the
sagittal arch view were used to make all arch measurements.
2D still-frames of the 4-chamber view were used to measure
left and right ventricular diameters. The same measurement
techniques were applied to all images. Color Doppler images
were not utilized to make measurements. Images with inad-
equate visualization of the aortic arch or ventricles were
excluded. All measurements were made by a single reader
(pediatric cardiology senior fellow) who was blinded to the
prenatal and postnatal diagnoses.
Statistical Analysis
Continuous variables representing patient characteristics
were summarized as medians (range), and were compared
among the three groups using the Wilcoxon Rank Sum test,
followed by the post-hoc pair-wise group comparisons with
the Mann–Whitney test. Categorical patient data were pre-
sented as counts (percent), and were compared using the
Chi-square test with post-hoc pair-wise Fisher’s Exact test.
Statistical significance for these analyses was established
at alpha of 0.017, using the Bonferroni correction for three
between-group comparisons. Linear mixed effects (LME)
modeling approach was used to examine the between-group
differences in the longitudinal trajectories of the fetal echo-
cardiographic measurements over time (gestation in weeks).

3. Pediatric Cardiology
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For each outcome of interest, we considered group, GA at
fetal echocardiogram and their interaction as the main fixed
effects, and a random intercept for each patient. We also
tested for the presence of a quadratic effect of time and sub-
ject-specific slopes using the likelihood ratio test for nested
models. Findings from the LME models were summarized
using least-square means (standard errors, SE). To adjust
for multiple comparisons in the LME regressions, we used
the Tukey–Kramer adjustment of p-values. Analyses were
performed using SAS 9.4 (Cary, NC) and the plots were cre-
ated using the statistical software R 3.4.3 and the packages:
ggplot2, nlme, and effects [15–18].
Results
Patient Characteristics
We identified 13 true CoA cases, 14 false positives and 30
controls. The groups did not vary significantly with respect
to GA at birth, GA at first fetal echocardiogram, gender,
race, and birth weight (Table 1). In the 27 cases with pre-
natal concern for CoA (true CoA + false positive groups), a
total of 91 fetal echocardiograms were performed throughout
gestation. Of these, 31 fetal echocardiograms (34%) were
excluded due to poor image quality. A partial set of meas-
urements (three or more) could be performed on 39 fetal
echocardiograms (42.9%) and a full set of measurements on
21 fetal echocardiograms (23.1%). In the 30 controls, a total
of 68 fetal echocardiograms were performed with 17 fetal
echocardiograms (25%) being excluded due to poor image
quality. A partial set of measurements (three or more) could
be performed on 31 fetal echocardiograms (45.6%) and a full
set of measurements on 20 fetal echocardiograms (29.4%).
(See Table 3 in “Appendix” for numbers of data collected
for each measurement type in each group).
Indications for fetal echocardiogram included family his-
tory of congenital heart disease (12), concern for congenital
heart disease (27), IVF pregnancy (7), Maternal diabetes
mellitus (5), and other/not specified (12). Of note, some
patients had multiple indications. Among the true CoA
cases, nine patients were referred for concern for congenital
heart disease, six of which were for primary concern for
CoA. The remaining three were concerns for a perimembra-
nous VSD, double outlet right ventricle with aortic stenosis,
and an interrupted aortic arch. The remaining four patients
in the true CoA group did not have an indication specified.
Among false positives, 13 referrals were for concerns for
congenital heart disease, of which 11 were for concern for
CoA and two for a dilated pulmonary artery. None of the
Fig. 1 Fetal echocardiographic
measurements. Note Structures
in figure not to scale

4. Pediatric Cardiology
1 3
control group patients were referred for concern for coarcta-
tion prenatally.
Comorbid conditions among true CoA cases included
seven patients with an associated bicuspid aortic valve, four
patients with a perimembranous VSD, two patients with
mitral stenosis, two patients with a muscular VSD and one
patient with a persistent left superior vena cava. In the false
positive group, there were three patients with a postnatal
diagnosis of a bicuspid aortic valve, one patient with a mus-
cular VSD and one patient with mitral stenosis. None of the
controls had additional defects aside from their muscular
VSDs.
All patients in the true CoA group underwent either
prenatal or postnatal genetic testing, which identified one
patient with trisomy 21 and one with Kabuki syndrome. Of
the seven patients in the false positive group who underwent
genetic testing, one patient was diagnosed with trisomy 21
and one with Turner syndrome. No genetic syndromes were
noted in the control group with only 10 of the patients hav-
ing undergone prenatal genetic testing.
Clinical Presentation
Review of clinical data demonstrated a significantly
higher proportion of true CoA cases with abnormal
femoral pulses (p < 0.001) and blood pressure differential
(p = 0.04) as compared to the other groups. Presence of
pre- to post-ductal saturation differential was rare and no
more likely in any of the groups (p = 0.10) (Table 2).
The majority of true CoA cases (92.3%) were initiated
on prostaglandins postnatally compared to 14.3% of false
positives and none in the controls (p < 0.001). Among
infants treated with prostaglandins, true CoA had longer
therapy (median of 3 days, range 0–7 days) compared to
infants with false positive findings (median of 0 days,
range 0–5 days, p < 0.001). All patients in the true CoA
and false positive groups were evaluated at birth by a pedi-
atric cardiologist. The median length of time in the hos-
pital “watching and waiting” for the ductus arteriosus to
close and awaiting a definitive diagnosis was significantly
longer among false positives (3 days, range 2–8 days)
than among the true CoA group (1 day, range 0–5 days,
p = 0.03). That is to say, the median age at the time of a
definitive diagnosis was 3 days in the false positive group
compared to 1 day in the true CoA group. All patients in
the true CoA group underwent surgical repair while none
in the false positive or control group underwent surgical
intervention. The median age at time of repair in the true
CoA group was 7 days (range 3–46 days).
Table 1 Demographics
a
All pair-wise differences are not significant at alpha = 0.017
b
Wilcoxon Rank Sum Test with post-hoc pair-wise Mann–Whitney test
c
Chi-square test with post-hoc pair-wise Fisher’s Exact test
Characteristic Group
True CoA
N = 13
False positives
N = 14
Controls
N = 30
p ­valuea
GA at time of fist fetal echo
Median (range) 21.80 (18.10–35.80) 27.00 (18.40–37.80) 22.80 (20.50–35.80) 0.14b
GA at birth
Median (range) 39.00 (37.00–40.00) 39.50 (31.20–40.10) 39.10 (33.50–41.70) 0.38b
Gender
F 5 (38.46%) 6 (42.86%) 21 (70.00%) 0.08c
M 8 (61.54%) 8 (57.14%) 9 (30.00%)
Race
Black 1 (7.69%) 2 (14.29%) 5 (17.86%) 0.87c
Hispanic 4 (30.77%) 3 (21.43%) 7 (25.00%)
Others 2 (15.38%) 1 (7.14%) 1 (3.57%)
White 6 (46.15%) 8 (57.14%) 15 (53.57%)
Birth weight (kg)
Median (range) 3.20 (1.75–4.44) 3.20 (1.60–4.09) 3.30 (2.13–4.11) 0.60b
Birth length (cm)
Median (range) 49.00 (41.5–53) 51.00 (42–54) 49.50 (30–54) 0.27b
Type of delivery
C-section 7 (53.85%) 3 (21.43%) 12 (42.86%) 0.21c
Vaginal delivery 6 (46.15%) 11 (78.57%) 16 (57.14%)

5. Pediatric Cardiology
1 3
Longitudinal Fetal Echocardiographic
Measurements/Indices
There were several echocardiographic variables that were
statistically different between the true CoA group versus
the other two groups. The most significant finding was a
longer average LCA–LSCA distance among true CoA cases
(mean = 5.25 mm, SE = 0.34 mm) as compared to the false
positives (mean difference = 2.41 mm, p < 0.0001) and the
controls (mean difference = 2.87 mm, SE = 0.38, p < 0.0001).
As gestation progresses, the LCA–LSCA distance remains
relatively unchanged among the false positives and the con-
trols, but increases at a significant rate among the true CoA
group (mean weekly change of 0.18 mm, SE = 0.05 mm,
p = 0.005) (Fig. 2, bottom left).
The brachiocephalic to LCA distance was also on
average longer in true CoA cases (mean = 3.21 mm,
SE = 0.28 mm) as compared to the false positives (mean
difference = 1.40 mm, SE = 0.34, p = 0.004) and to the con-
trols (mean difference = 1.08 mm, SE = 0.32 mm, p = 0.01).
We also observed an average weekly increase of 0.05 mm
(SE = 0.02) in this measure for all groups (p = 0.03) (Fig. 2,
top right).
The aortic isthmus (p < 0.0001 for relevant group com-
parisons) and distal transverse arch diameter (p = 0.005,
0.04) were significantly smaller in true CoA cases [means
of 2.19 mm (SE = 0.13 mm) and 2.52 mm (SE = 0.18 mm),
respectively] and false positives [means of 2.14 mm
(SE = 0.13 mm) and 2.81 mm (SE = 0.15 mm), respec-
tively] as compared to the controls [means of 3.04 mm
(SE = 0.09 mm) and 3.25 mm (SE = 0.12 mm), respectively],
but could not differentiate between the first two groups.
The average weekly increase in the aortic isthmus and dis-
tal transverse arch diameter was 0.10 mm (SE = 0.01 mm)
across all groups (p < 0.0001).
Of the three previously studied postnatal indices that
we applied to fetal echocardiograms, we found the DT/
LCA–LSCA index to be on average significantly smaller
throughout gestation among true CoA cases (mean = 0.59,
SE = 0.20) as compared to the false positives (mean differ-
ence = − 0.67, SE = 0.25, p = 0.04) and to the controls (mean
difference = − 0.88, SE = 0.23, p = 0.004). This index also
significantly increased by 0.04 (SE = 0.01) for each 1 week
of fetal gestational growth (p = 0.008) (Fig. 2, top left).
While the LV-to-RV ratio was smaller in both true CoA
cases (mean = 0.79, SE = 0.04, p = 0.007) and false posi-
tives (mean = 0.83, SE = 0.04, p = 0.01) as compared to the
controls (mean = 0.97, SE = 0.03), it could not differentiate
between the first two groups. A linear decrease in the LV-
to-RV ratio was observed across all groups (mean = − 0.006,
SE = 0.003, p = 0.04). Lastly, the LCA/DT index, as gesta-
tion progresses, increases among the false positives while
it decreases among true CoA cases (p < 0.03), serving as
a potential differentiator of the two groups (Fig. 2, bottom
right).
There were no between-group statistically significant
differences observed for ascending aorta diameter and
proximal transverse arch diameter, with an observed linear
weekly increase of 0.14 mm (SE = 0.02 mm, p < 0.0001) and
0.11 mm (SE = 0.01 mm, p < 0.0001), respectively.
There was no statistically significant difference seen for
ascending aorta diameter, proximal transverse arch diam-
eter, and LCA diameter between the three groups. There
was an average linear weekly increase in the LCA diam-
eter: 0.06 mm (SE = 0.01 mm) per fetal gestational week
and compared to the false positives (mean = 1.68 mm,
SE = 0.07 mm), true CoA cases (mean = 1.38, SE = 0.05 mm,
p = 0.027) and controls were smaller (mean = 1.39,
SE = 0.05 mm, p = 0.01).
Discussion
Accurate fetal diagnosis of coarctation can be difficult.
There are several guidelines used to determine a prena-
tal concern for coarctation, but these are nonspecific and
carry a high false positive rate [19–21]. Previous studies
have identified indices such as LCA to distal transverse arch
diameters (LCA/DT) and distal transverse arch diameter to
LCA–LSCA distance (DT/LCA–LSCA), that have only been
applied to postnatal echocardiograms [1, 2, 8–12]. Our study
examined several fetal echocardiographic arch and ventric-
ular measurements and applied these previously identified
postnatal indices to identify prenatal predictors of CoA. To
Table 2 Clinical characteristics
a
Chi-square test
b
Fisher’s Exact test for all pair-wise differences are significant at
alpha = 0.017
c
Fisher’s Exact test for all pair-wise differences are not significant at
alpha = 0.017
d
Fisher’s Exact test is significant at alpha = 0.05
Characteristic Group p-Valuea
True CoA
N = 13
False positives
N = 14
Controls
N = 30
Femoral pulses
Abnormal 8 (61.54%) 1 (7.14%) 1 (3.33%) < 0.001b
Normal 5 (38.46%) 13 (92.86%) 29 (96.67%)
Pre- and post-ductal sat differential
No 11 (84.62%) 13 (92.86%) 28 (100%) 0.10c
Yes 2 (15.38%) 1 (7.14%) 0 (0%)
BP gradient
No 6 (46.15%) 12 (85.71%) N/A 0.04d
Yes 7 (53.85%) 2 (14.29%) N/A

6. Pediatric Cardiology
1 3
our knowledge, this is first study to apply these previously
studied postnatal indices to fetal echocardiograms.
In our study, the DT/LCA–LSCA index was a significant
predictor of postnatal coarctation and differentiated true
CoA patients from the false positive prenatal diagnoses and
control patients. This index dubbed the carotid-subclavian
artery index by Dodge-Khatami et al. has been validated by
several studies in postnatal echocardiograms to be a sensi-
tive predictor (97.7% sensitive for neonates [2]) of coarc-
tation independent of the presence of a ductus arteriosus,
age or other cardiac defects [2, 8, 11, 22]. Our findings
suggest postnatal indices predictive of CoA can be utilized
prenatally.
As seen in prior prenatal studies, we found the
LCA–LSCA distance was significantly longer in the true
coarctation group [2, 23]. Our results support that a longer
LCA–LSCA distance can be used throughout gestation as
marker of coarctation. We also found the aortic isthmus and
LV/RV ratio were not significant predictors of postnatal
coarctation. While both were smaller in the true CoA group,
the same differences were seen in the false positive group
and could not differentiate the two groups. This is consistent
with what is reported in the literature in that these markers
are non-specific and carry a high false positive rate [6, 7].
We found the brachiocephalic–LCA distance is also
longer in true CoA case as compared to false positives and
controls. Akhfash et al. and Dodge-Khatami et al. in their
studies of postnatal patients also found statistically signifi-
cant longer brachiocephalic–LCA distances in CoA patients
[2, 11]. The predictive value in CoA was not evaluated.
While the LCA/DT index has been noted by Morrow et al.
to be significantly larger in CoA patients than in controls,
we did not see this trend in our study [23]. We found that
as gestation progressed, the LCA/DT index trend increased
Fig. 2 Trend of mean measurements over gestation with standard error for top left: DT/(LCA–LSCA) index. Top right: Brachiocephalic–LCA
distance, bottom left: LCA–LSCA distance, and bottom right: LCA/DT index

7. Pediatric Cardiology
1 3
for false positives while it decreased in the true CoA group.
This is in part due to the larger LCA diameter seen in false
positives as compared to true CoA cases and controls. It is
unclear why the LCA diameter, and thereby the LCA/DT
index, would be larger in false positives, but if validated,
could serve as a potential differentiator of true CoA cases
from false positives; i.e. differentiate which of those patients
with prenatal concern for CoA are more likely to develop
CoA postnatally.
These fetal measurements and indices may help provide
earlier, accurate identification of CoA. It is unlikely that
any one of these measurements or indices in isolation will
serve as the sole predictor of CoA, but rather, similar to
Soslow et al.’s findings, will be a group of parameters that
can provide with some accuracy the likelihood of developing
a CoA. A large, prospective study is needed to validate these
findings and to identify clinical cut-off values for diagnostic
accuracy.
Limitations
The study was conducted at single center. The cohorts in our
study were relatively small and further prospective valida-
tion is needed with a larger sample size. Due to the inherent
limitations of a retrospective study, we were unable to iden-
tify a substantial number of patients with a false negative
result (i.e. normal fetal echocardiogram with a coarctation
on postnatal echocardiogram) for comparison. Our small
sample size also limits our ability to provide critical thresh-
old values for the identified statistically significant measure-
ments or gestationally based normative values. Additionally,
fetal echocardiograms are inherently limited compared to
postnatal echocardiograms due to dependency on fetal posi-
tion, GA and quality of image windows through the maternal
abdomen such that a clear aortic arch image may not neces-
sarily be obtainable in every fetus. As such, several fetal
echocardiograms had to be excluded due to inadequate or
poor image quality; however, our analytic approach (LME)
assured that none of the patients in the study sample were
excluded from the longitudinal analyses. The measurements
were made by a single reader, and the reproducibility of our
measures was not assessed in this study. Furthermore, we did
not include complex congenital heart lesions in our study,
potentially limiting the generalizability of our findings.
Conclusions
Fetal echocardiographic markers such as the DT/
LCA–LSCA index, LCA–LSCA distance, and brachioce-
phalic–LCA distance are significant predictors of postnatal
coarctation. The LCA/DT index trend over time can help
differentiate which of those patients with prenatal concern
for coarctation are more likely to develop coarctation post-
natally. The use of fetal echocardiographic markers may
improve prenatal detection and accurate prediction of post-
natal coarctation. Further prospective studies with a larger
cohort of patients are needed to validate these results and to
identify normative and threshold values.
Acknowledgements This publication was made possible by CTSA
Grant Number UL1 RR024139 from the National Center for Research
Resources (NCRR) and the National Center for Advancing Transla-
tional Science (NCATS), components of the National Institutes of
Health (NIH), and NIH roadmap for Medical Research. Its contents are
solely the responsibility of the authors and do not necessarily represent
the official view of NIH.
Compliance with Ethical Standards
Conflict of interest All authors declare no conflict of interest.
Ethical Approval This article does not contain any studies with human
participants or animals performed by any of the authors.
Informed Consent This study was a retrospective review of imaging
studies previously completed. Informed consent was not necessary as
deemed by our institutional review board.
Appendix
See Table 3.

8. Pediatric Cardiology
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nosing neonatal aortic coarctation in the setting of patent duc-
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Table 3 Numberofindividualmeasurementscollectedbygrouptype
LCAleftcarotidartery,LSCAleftsubclavianartery,LVleftventricle,RVrightventricle,DTdistaltransversearch
Group
(total#offetalechoes)
AscendingaortaProximal
transverse
arch
Distaltrans-
versearch
AorticisthmusLCABrachioce-
phalic–LCA
LCA–LSCALVRVLCA/DTDT/LCA–LSCA
TrueCoA
(49)
30(61.2%)18(36.7%)17
(34.7%)
31
(63.3%)
14
(28.6%)
7
(14.3%)
11
(22.4%)
33
(67.3%)
32
(65.3%)
11
(22.4%)
9
(18.4%)
Falsepositive
(42)
30
(71.4%)
22
(52.4%)
26
(61.9%)
32
(76.2%)
18
(42.9%)
17
(40.5%)
19
(45.2%)
32
(76.2%)
32
(76.2%)
18
(42.9%)
18
(42.9%)
Controls
(68)
48
(70.6%)
39
(57.4%)
38
(55.9%)
50
(73.5%)
31
(45.6%)
26
(38.3%)
31
(45.6%)
54
(79.4%)
54
(79.4%)
27
(39.7%)
29
(42.6%)

9. Pediatric Cardiology
1 3
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J Am Coll Cardiol 8(3):616–620. https​://doi.org/10.1016/S0735​
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