Pictorial essay
Med Ultrason 2015, Vol. 17, no. 4, 545-549
DOI:
Prenatal diagnosis of placenta and umbilical cord pathologies
by three-dimensional ultrasound: pictorial essay.
Guilherme de Castro Rezende1, Edward Araujo Júnior2
1Department
of Obstetrics and Gynecology, Center of Fetal Medicine, Federal University of Minas Gerais (UFMG),
Belo Horizonte-MG, 2Department of Obstetrics, Paulista School of Medicine-Federal University of São Paulo (EPMUNIFESP), São Paulo-SP, Brazil.
Abstract
The authors present their experience in prenatal diagnosis of placental and umbilical cord pathologies, using three-dimensional ultrasound (3DUS) in the rendering and tomography ultrasound imaging (TUI) modes, associated with color Doppler
in some cases. Cases of placenta accreta/placenta previa, circumvallate placenta, succenturiate lobe, true knot of the umbilical
cord, nuchal cord, and marginal/velamentous umbilical cord insertion are presented. 3DUS can contribute to improve the accuracy of prenatal diagnosis of placenta and umbilical cord pathologies.
Keywords: prenatal diagnosis, placenta, umbilical cord, Doppler ultrasonography, 3D ultrasound.
Introduction
Ultrasound professionals often underestimate the
value of ultrasonographic evaluations of the placenta and
umbilical cord. Placenta and umbilical cord abnormalities may have important prognostic implications for perinatal morbidity and mortality. In recent years, with the
advancement of high-resolution ultrasound, the three-dimensional ultrasound (3DUS), associated in some cases
with color and/or power Doppler, has become an important prenatal diagnostic tool [1-3].
This pictorial essay presents the authors’ experience
while using 3DUS (associated in some cases with color
and/or power Doppler) in the diagnosis of placenta and
umbilical cord pathologies.
Received 22.03.2015 Accepted 21.04.2015
Med Ultrason
2015, Vol. 17, No 4, 545-549
Corresponding author: Prof. Edward ARAUJO JÚNIOR, PhD
Department of Obstetrics, Paulista School of
Medicine-Federal University of São Paulo
(EPM-UNIFESP)
Rua Belchior de Azevedo, 156, apto. 111
Torre Vitoria, São Paulo–SP, Brazil
CEP 05089-030
Phone/Fax: +55-11-37965944
E-mail: [email protected]
Placenta accreta
Placenta accreta (defined as an abnormal adherence of
the placenta to the uterus, rendering the separation from
the uterus difficult or impossible) is a rare complication,
with an estimated prevalence of 1 in 2,500 pregnancies.
Nonetheless, it has become an important etiology of maternal morbidity and mortality, as it is the leading cause
of emergency peripartum hysterectomy [1,4]. Clinically,
the main feature of placenta accreta is abundant uteroplacental neovascularization, which can cause severe
and difficult-to-treat bleeding [1,5]. The prevalence of
placenta accreta has been increasing, and the most common predisposing conditions are prior cesarean section
and placenta previa [1,6].
A prenatal diagnosis of placenta accreta is essential
for proper delivery preparation and, usually, for the performance of a cesarean hysterectomy [1,6]. The ultrasound diagnosis is based on gray-scale findings, which
can be associated with color Doppler and 3DUS. Among
these findings, irregularly shaped placental lacunae, thinning of the myometrium, in which the placenta is implanted, and loss of retroplacental hypoechoic area are
notable [1,5]. In figure 1 are shown some examples of
this pathology.
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Guilherme de Castro Rezende et al
Prenatal diagnosis of placenta and umbilical cord pathologies
Circumvallate placenta
branes [2,7]. The incidence of circumvallate placenta
varies from 0.5% to 18% in postpartum placental examinations [2]. This placental form is associated with
an increased risk of several perinatal complications,
particularly amniotic rupture, intrauterine growth restriction, abruptio placentae, fetal malformation, and
perinatal death [2].
Circumvallate placenta is an abnormality in the
shape of the placenta in which the membranes are inserted from the inside towards the edge and through
the center of the placenta. It is characterized by cylindrical, peripherally thickened chorioamniotic mem-
Fig 1. a) Longitudinal plane of the three-dimensional (3D) image with HD flow of the cervix and anterior lower uterine segment,
using tomography ultrasound imaging (TUI) software, evidencing loss of placental hypoechoic area (white arrows) in a case of placenta accrete in the third-trimester of pregnancy; b) cervix and anterior lower uterine segment using TUI software, showing loss of
placental hypoechoic area; c) cervix and anterior lower uterine segment using TUI software, evidencing loss of placental hypoechoic
area; d) photograph of the same uterus after a cesarean hysterectomy and after longitudinal incision, showing placental invasion into
the myometrium at the segment region (black arrows); e) longitudinal and transverse planes of the 3D image of the cervix and anterior lower uterine segment using TUI software, showing the placenta bypassing the internal opening of the cervix, and the presence
of placental hypoechoic area (white arrows), placenta previa. BEX: bladder; PLAC: placenta; COLO: cervix.
Fig 2. a) Two-dimensional image of a transverse plane of the placenta, showing thick peripheral edges and corners, circumvallate
placenta (white arrows), in a third-trimester pregnancy; b) Three-dimensional image with the HD live software of a circumvallate
placenta, showing thick peripheral edges and curves (white arrow) in a pregnancy in the third trimester, with light incidence at 1
o’clock; c) Three-dimensional image with HD live software of a circumvallate placenta, evidencing thick peripheral edges and
curves (white arrow), appearance of a tire mounted on a wheel, with light incidence at 1 o’clock, in a third-trimester pregnancy.
Med Ultrason 2015; 17(4): 545-549
Two-dimensional ultrasonographic findings are described as a placental band or placental shelf, specifically
the thick, cylindrical placental edge [2] (fig 2). Nonetheless, the prenatal diagnosis of circumvallate placenta is
rare [2]. Figures 2B and 2C illustrate, through 3DUS
with HD live software, a finding described as the “tire”
sign, in which a circular depression with a thick peripheral ring on the chorionic plate is observed, resembling a
tire mounted on a wheel [2].
Succenturiate lobe
Succenturiate lobe or accessory lobe is recognized by
ultrasonography as a mass of placental tissue separated
from the main lobe, occurring in approximately 5% of
pregnancies [7] (fig 3). This finding is correlated with a
higher incidence of velamentous umbilical cord insertion, vasa previa, and placental infarction [8].
Marginal/velamentous umbilical cord insertion
Fig 3. a) Three-dimensional image with HD live software of a
circumvallate placenta, evidencing thick peripheral edges and
curves (white arrows) and the appearance of a tire mounted on
a wheel, with light incidence at 1 o’clock, in a third-trimester
pregnancy; b) Three-dimensional image with HD live software,
evidencing both main and accessory lobes (white arrows) with
central light incidence, in a third-trimester pregnancy.
The insertion of the umbilical cord at the edge of the
placenta, known as battledore placenta, occurs in 7% of
pregnancies [7]. In 1% of all pregnancies, the umbilical
cord falls beyond the placental edge, allowing a variable
portion of the umbilical cord to remain between the two
Fig 4. a) Three-dimensional image with HD live software, showing a marginal insertion of the umbilical cord (white arrows), with
light incidence at 9 o’clock, in a third-trimester pregnancy; b) Transverse and longitudinal planes of the three-dimensional image
with HD flow of the placental margin, using tomography ultrasound imaging (TUI) software, evidencing the insertion of the cord, in
a third-trimester pregnancy; c) Longitudinal plane of two-dimensional image with color Doppler of the velamentous umbilical cord
insertion, in a third-trimester pregnancy; d) Postpartum placenta photography, confirming the diagnosis of velamentous umbilical
cord insertion (white arrow).
Fig 5. a) Two-dimensional image with power Doppler of a longitudinal plane of the umbilical cord, suggesting a true knot of the
umbilical cord (white arrow) in a third-trimester pregnancy; b) Three-dimensional image with power Doppler of a longitudinal plane
of the umbilical cord, suggesting a true knot of the umbilical cord (white arrow) in a third-trimester pregnancy; c) Postnatal umbilical
cord photography, confirming the diagnosis of true knot of the umbilical cord (white arrow); d) Three-dimensional image with HD
flow of a false knot of the umbilical cord, in a third-trimester pregnancy.
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Fig 6. a) Two-dimensional image with HD flow in a transverse plane at the level of the cervical region, in which the umbilical cord
vessels are seen surrounding the fetal neck in a third-trimester pregnancy; b) Two-dimensional image with HD flow of a longitudinal
plane at the level of the cervical region, in which the umbilical cord vessels are seen around the fetal neck, and a quadruple nuchal
cord can be identified, in a third-trimester pregnancy; c) Three-dimensional power Doppler at the level of the cervical region, in
which the umbilical cord vessels are seen around the fetal neck and a quadruple nuchal cord can be identified, in a third-trimester
pregnancy.
membranes without the protection of the Wharton’s jelly
[7,9]. This condition is associated with fetal growth restriction, congenital anomalies, retained placenta, and
prematurity, in addition to rupture, thrombosis of the
umbilical vessels, and fetal death [7,9]. The ultrasound
diagnosis is possible; placental cord insertion should be
routinely tracked at obstetric ultrasound [7,9] (fig 4).
True knot of the umbilical cord
A true knot of the umbilical cord is observed in approximately 0.3%–2.1% of births [10]. Although it is a
rare event, this finding is associated with serious consequences. Fetal mortality rate can be four to ten times
higher when compared with that of the general obstetric
population [3]. It can also be associated with a non-reassuring fetal heart rate pattern during labor and higher incidence of cesarean section [10]. Some obstetric factors are
described to be correlated with true knot of the umbilical
cord: polyhydramnios, gestational diabetes, fetuses that
are small for gestational age, long umbilical cord, male
fetus, and genetic amniocentesis [10]. Prenatal diagnosis
of true knot of the umbilical cord became possible with
the modernization of ultrasound equipment; however, it
is still an uncommon diagnosis [3,10]. Ultrasound with
gray scale, color Doppler, two- and three-dimensional
power Doppler, and 3DUS with HD flow software are
used in the diagnosis of this condition, which is suspected by the visualization of a “loop” (fig 5).
Nuchal cord
Nuchal cord is defined as a 360° turn of the umbilical cord around the fetal neck [11]. The prevalence of
nuchal cord at delivery has been reported to be between
6% and 37% [11]. The prevalence of single, double, tri-
ple, and quadruple nuchal cord was described by Shui et
al to be of 10.6%, 2.5%, 0.5%, and 0.1%, respectively
[12]. There is a linear increase in the prevalence of single
or multiple nuchal cords with advancing gestational age
[11,12]. Prenatal diagnosis of nuchal cord is not routinely
done, but there is a correlation between this event and
abnormal fetal heart rate pattern during labor [11]. The
sagittal and transverse planes at the fetal neck level allow
for a precise diagnosis [12], and the sensitivity of diagnosis usually improves with the use of color Doppler and
3DUS [11,12] (fig 6).
Conclusions
With technological advancement, new possibilities in
diagnostic imaging are made available for the antenatal
period [13]. 3DUS has been used as a complementary
technique for prenatal diagnosis of placenta and umbilical cord pathologies [1-3]. Some of these conditions,
which are associated with high perinatal morbidity and
mortality, have a low antenatal detection rate as they are
often diagnosed at birth or postpartum [1,3,6]. Prenatal
diagnosis of these pathologies allows for the quantification of risks, prenatal and delivery programming, and
guidance to families, having a significant impact on the
follow-up of these patients. 3DUS also allows for data
storage, which can be forwarded for review to tertiary
centers.
Conflict of interest: none
References
1.Shih JC, Palacios Jaraquemada JM, Su YN, et al. Role of
three-dimensional power Doppler in the antenatal diagnosis
of placenta accreta: comparison with gray-scale and color
Med Ultrason 2015; 17(4): 545-549
Doppler techniques. Ultrasound Obstet Gynecol 2009; 33:
193-203.
2.Arlicot C, Herve P, Simon E, Perrotin F. Three-dimensional
surface rendering of the chorionic placental plate: the “tire”
sign for the diagnosis of a circumvallate placenta. J Ultrasound Med 2012; 31: 337-341.
3.Rodriguez N, Angarita AM, Casasbuenas A, Sarmiento A.
Three-dimensional high-definition flow imaging in prenatal
diagnosis of a true umbilical cord knot. Ultrasound Obstet
Gynecol 2012; 39: 245-246.
4.Clark SL, Koonings PP, Phelan JP. Placenta previa/accreta
and a prior cesarean section. Obstet Gynecol 1985; 66: 89-92.
5.Comstock CH. Antenatal diagnosis of placenta accreta: a
review. Ultrasound Obstet Gynecol 2005; 26: 89-96.
6.Oyelese Y. Placenta previa: the envolving role of ultrasound. Ultrasound Obstet Gynecol 2009; 34: 123-126.
7.Benirschke K, Kaufmann P. (eds.). Placental shape aberrations. In: Pathology of the Human Placenta. 4th ed. New
York: Springer-Verlag, 2000: 399-414.
8.Jeanty P, Kirkpatrick C, Verhoogen C, et al. The succenturiate placenta. J Ultrasound Med 1983; 2: 9-12.
9.Sepulveda W, Rojas I, Robert JA, Schnapp C, Alcalde JL.
Prenatal detection of velamentous insertion of the umbilical
cord: a prospective color Doppler ultrasound study. Ultrasound Obstet Gynecol 2003; 21: 564-569.
10.Hershkovitz R, Silberstein T, Sheiner E, et al. Risk factors
associated with true knots of the umbilical cord. Eur J Obstet Gynecol Reprod Biol 2001; 98: 36-39.
11.Peregrine E, O’Brien P, Jauniaux E. Ultrasound detection of nuchal cord prior to labor induction and the risk
of cesarean section. Ultrasound Obstet Gynecol 2005; 25:
160-164.
12.Sherer DM, Manning FA. Prenatal ultrasonographic diagnosis of nuchal cord(s): disregard, inform, monitor or intervene? Ultrasound Obstet Gynecol 1999; 14: 1-8.
13.Tonni G, Araujo Junior E. Three-dimensional ultrasound in
obstetrics practice: myth or reality? Rev Bras Ginecol Obstet 2014; 36: 143-145.
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