Chapter 22: Abnormalities of the Placenta and Umbilical Cord Flashcards
1
Q
Focal dilation of an artery
A
aneurysm
2
Q
placenta where the lobes are nearly equal in size and the cord inserts into the chorionic bridge of tissue that connects the two lobes
A
bilobed placenta
3
Q
fatal condition associated with multiple congenital anomalies and absence of the umbilical cord
A
body stalk anomaly
4
Q
very rare condition where there is massive subchorionic thrombosis of the placenta secondary to extreme venous obstruction
A
Breus mole
5
Q
Attachment of the placenta membranes to the fetal surface of the placenta rather than to the underlying villous placental margin
A
extrachorial placenta
6
Q
bending, twisting, and bulging of the umbilical cord vessels mimicking a knot in the umbilical cord
A
false knot
7
Q
Periumbilical abdominal wall defect, typically to the right of normal cord insertion that results in free-floating bowel within the amniotic fluid
A
gastoschisis
8
Q
condition characterized by multiple complex fetal anomalies and a short umbilical cord
A
Limb-body wall complex
9
Q
occurs when the umbilical cord inserts at the placental margin
A
marginal insertion or battledore placenta
10
Q
central anterior abdominal wall defect at the site of cord insertion into the fetal abdomen that results in abdominal organs protruding outside the abdominal cavity but contained by a covering membrane consisting of peritoneum, Wharton jelly, and amnion
A
omphalocele
11
Q
term that refers to a thickened or hydropic placenta
A
placentamegaly
12
Q
Linear extra-amniotic tissue that projects into the amniotic cavity with no restriction of fetal movement
A
synechia (asherman syndrome)
12
Q
intraplacental area of hemorrhage and clot
A
thrombosis
13
Q
result of the fetus actually passing through a loop or loops of umbilical cord creating one or more knots in the cord
A
true knot
13
Q
vascular structure connecting the fetus and placenta that normally contains two arteries and one vein surrounded by Wharton jelly
A
umbilical cord
13
Q
Method of assessing the degree of umbilical cord coiling, defined as the number of complete coils per centimeter length of cord
A
umbilical coiling index (UCI)
14
Q
failure of the normal physiological gut herniation to regress into the abdomen, resulting in a small amount of bowel protruding into the base of the umbilical cord
A
umbilical hernia
15
Q
tubular, anechoic structures found beneath the chorionic plate that correspond to blood-filled spaces found at delivery
A
venous lakes
16
Q
Decreased placental thickness is considered when placenta is less than ____
A
1.5 cm
17
Q
inferior margin of the placenta is within 2 cm of the internal cervical os
A
low-lying placenta
18
Q
placental tissue entirely covers the internal cervical os
A
placenta previa`
19
Q
choriona villi adhere directly to but do not invade the myometrium
A
placenta accreta
20
Q
chorionic villi invade the myometrium
A
placental increta
21
Q
chorionic villi invade through the myometrium into the uterine serosa and potentially into surrounding tissues
A
placenta percreta
22
First trimester sonographic markers for ______ are:
gestational sac implantation in the lower uterine segment
multiple irregular vascular spaces within the placental bed
cesarean scar implantation of the gestational sac
morbidly adherent placenta
23
Late second and third trimester sonographer markers for ______ are:
placenta previa
multiple vascular lacunae within placenta
loss of normal hypoechoic retroplacental zone
abnormal uterine serosa-maternal bladder interface
morbidly adherent placenta
23
What is the placenta responsible for?
nutritive, respiratory, and excretory functions
23
used to describe appearance based on amount of placental calcifications and degree of maturation
placental grading
24
The placenta should be between __ cm and __ cm.
2
4
25
"jelly-like placenta"
IUGR
26
The placenta normally develops where chorionic villi interfacing the ______ grow.
decidua basalis
26
selective loss of parts of placenta and growth of other parts
presumed to occur beauce placenta preferentially grows where there is sufficient decidua and vascular supply and atrophies where condition less favorable
trophoblastic trophotropism
27
presence of one or more small accessory lobes that develop in membranes at a distance from periphery of main placenta
succenturiate lobe
28
ring shaped placenta
annular placenta
29
Annular placenta and PM are associated with ______
placenta previa
29
placenta extending beyond limits of chorionic plate with attachment of placental membranes to the fetal surface of the placenta, inward from the edge, rather than to underlying villous placenta margin
placenta extrachorialis
29
2 types of placenta extrachorialis
placenta circummarginate
placenta circumvallate
29
fetal membrane insertion is flat
may be found in 20% of placentas
placenta circummarginate
29
transition where fetal membranes of chorionic plate terminate; has a rolled or raised edge
placenta circumvallate
30
implantation of placenta into lower part of the uterus covering internal cervical os, thus delivering before fetus
placenta previa
31
irregular subchorionic marginal cystic structures or infolding of placental margin with a thick, curled peripheral edge
placenta circumvallate
31
linear structure protruding into fluid-filled amniotic cavity
placenta circumvallate
32
inferior margin of placenta covers internal cervical os
placenta previa
33
inferior margin within 2 cm of internal os
low-lying placenta
33
abnormal implantation of placental into uterine wall
morbidly adherent placenta
34
involves a defect in the decidua basalis; allows chorionic villi to invade the myometrium
morbidly adherent placenta
35
occurs when the chorionic villi becomes abnormally adherent to uterine myometrium rather than uterine decidua; accounts for about 75% of cases
placenta accreta
36
occurs when there is villous infiltration into the myometrial surface; occurs in 18% of cases
placenta increta
37
chorionic villi infiltrate and penetrate through entire myometrium, breaching serosa, potentially invading surrounding maternal organs; occurs in 7% of cases
placenta percreta
38
Most common reason for emergency postpartum hysterectomy
morbidly adherent placenta
39
optimal time for delivery with MAPs
34-35 weeks after corticosteroid injection given
40
Two most important risk factors to MAPs
placenta previa
previous c-section
41
gestational sac embedded into cesarean section scar at level of internal cervical os at base of maternal urinary bladder
cesarean section scar implantation
42
Most common location of MAPs
anterior implantation in the lower uterine segment
43
irregular anechoic structures within placental parenchyma found beneath the chorionic plate
placental lakes
44
speculated to be end result of intervillous and subchorionic thrombosis; results from pooling and stasis of maternal blood in perivillous and subchorionic spaces
fibrin depositions
45
hypoechoic lesions in subchorionic area or within placental mass, or as linear echogenicities streaks within an anechoic lesions
fibrin depositions
45
intraplacental area of hemorrhage and clot
intervillous thrombosis
46
hypoechoic placental lesions of varying size that may contain linear echogenicities representing fibrin deposits
intervillous thrombosis
47
most commonly found midway between subchorionic and basal areas of placenta
intervillous thrombosis
48
massive subchorionic hematoma and thrombosis; heterogeneous and hypoechoic lesions
Breus mole
48
_______ may appear hypoechoic or show placental thinning
necrotic infarct
48
occurs as a result of obstruction of spiral arteries; usually found at periphery of placenta
placental infarction
48
most often found near the umbilical cord insertion under the thin amniotic layer covering the chorionic plate
subamniotic cysts/hematomas
49
result from rupture of chorionic (fetal) vessels close to umbilical cord insertion into placenta
subamniotic cysts/hematomas
49
two primary nontrophoblastic tumors
chorioangioma and teratoma
49
benign vascular malformation of the placenta arising from primitive chorionic mesenchyme
chorioangioma
49
can be associated with:
elevated maternal serum alfa-fetoprotein
beta-human chorionic gonadotropin levels
chorangioma
49
contain arteriovenous shunts that can lead to severe fetal complications
chorioangiomas
49
classifications of placental abruptions
retroplacental hemorrhage
intraplacental hemorrhage
marginal hemorrhage
subchorionic blood clot
49
sonographic diagnosis based on increased vascularity or a large feeding vessel inside tumor with same pulsation rate as umbilical cord
chorangioma
49
well-circumscribed hyperechoic or hypoechoic ovoid mass protruding from fetal surface of placenta near cord insertion
chorangioma
49
very rare; usually benign but can be highly malignant; may contain structures derived from three germ cell layers; complex mass of placenta with cystic and solid components; calcifications may be present
Teratoma
50
vascularization is supplied by fetal circulation through arteriovenous shunts from umbilical cord
chorangioma
50
premature separation of all or part of the placenta from underlying myometrium
placental abruption
50
What artery is the artery that a Doppler measurement taken from to assess chorangioma?
middle cerebral artery
51
Prognosis of placental abruption depends on:
degree of placental attachment
gestational age
52
Gravest prognosis of placental abruption
significant retroplacental hemorrhage involving over 30-40% of placenta
53
amnion is visible as a discrete free-floating membrane separate from the chorion surrounding the fetus
sonographic diagnosis of chorioamniotic separation
54
Most common fetal membrane abnormality structures or conditions
chorioamniotic separation
elevation resulting from subchorionic hemorrhage
membranes associated with multiple gestations and blighted ova
intrauterine synechiae
55
linear, extra-amniotic tissues that project into the amniotic cavity
amniotic sheets or intrauterine synechiae
56
sporadic condition that is thought to occur as a result of rupture of the amnion without rupture of chorion
amniotic rupture sequence or amniotic band syndrome
57
early rupture can result in malformations of cranium, central nervous system, face, and viscera
amniotic rupture sequence of amniotic band syndrome
58
In amniotic band syndrome, bands may tear or disrupt previously normally developed structures leading to:
congenital amputations
constriction rings
bizarre nonanatomic facial clefts
59
designation given to several disorders arising from either normal or abnormal fertilization of an ovum resulting in neoplastic changes in trophoblastic elements of developing blastocyst
Gestational Trophoblastic disease
60
classifications of gestational trophoblastic disease
complete or partial hydadatidform mole
metastic disease or choriocarcinoma
61
chorionic villi that are markedly hydropic and swollen; proliferation of the trophoblast cell resulting in excessive production of beta-human chorionic gonadotropin levels
complete hydadatidform mole; molar pregnancy
62
distention of uterine cavity by a heterogeneous echogenic mass with a snowstorm appearance; enlarged uterus filled with multiple variable-sized small anechoic cysts
molar pregnancy
63
absence of both amniotic fluid and a fetus
complete mole
64
presence of co-existing fetus along with an enlarged, thickened placenta with multiple cystic spaces
partial mole
65
represent deep growth of abnormal tissue into and beyond the myometrium
invasive mole
66
considered locally invasive non-metastasizing neoplasms
invasive mole
67
capable of metastasizing; appear as heterogeneous, echogenic, and hypervascular masses
choriocarcinomas
68
rare vascular placental anomaly; characterized by mesenchymal stem villous hyperplasia; presents as an enlarged placenta; may be mistaken for molar pregnancy
placental mesenchymal dysplasia
69
placentomegaly; dilatation of chorionic vessels; large areas of cystic villous changes along with areas of normal placenta
placental mesenchymal dysplasia
70
The umbilical cord normally contains ___ arteries and ___ veins surrounded by Wharton jelly, all enclosed in a layer of amnion.
2, 1
71
one of the most common congenital anomalies of the umbilical cord
single umbilical artery
72
possible mechanisms of SUA
primary agenesis of one artery
atrophy or atresia of a previously present artery
persistence of original allantoic artery in body stalk of embryo
73
The ____ umbilical artery is more commonly absent.
left
74
presence of more than 3 vessels
supernumerary vessels
75
exclusively associated with conjoined twinning
supernumerary vessels
76
may represent an abnormal splitting of umbilical vessels between the 3rd and 5th week of development
supernumerary vessels
77
condition where right umbilical (portal) vein, rather than left-sided umbilical vein, remains open
persistent right umbilical vein
78
umbilical cord vein curves toward left-sided stomach rather than toward liver; gallbladder located medial to vein rather than lateral
persistent right umbilical vein
79
a focal dilatation of umbilical vein
umbilical vein varix
80
The abdominal vein is greater than __ mm in umbilical vein varix.
9
81
Enlargement of the varix of umbilical vein varix of at least ____ larger than diameter of intrahepatic umbilical vein.
50%
82
complete absence of umbilical cord
body stalk anomaly
83
fatal condition linked to maternal cocaine use
body stalk anomaly
84
very short cord
limb-body wall complex
85
average normal length of umbilical cord
55 cm
86
considered an index of fetal activity and depends on tension created by freely mobile fetus primarily during second and third trimesters
length of cord
87
defined as 35 cm or less
short cord
88
vascular occlusions predisposal to long cord
thrombi and true knots
stricture
nuchal cord
cord entanglement
cord prolapse during labor
89
at or near center of placental disk in over 90% of cases
normal insertion of umbilical cord
90
also known as battledore placenta; cord inserts within a centimeter of placental margin rather than centrally
marginal insertion
91
umbilical vessels separate and course between amnion and chorion at a distance from placental margin surrounded only by a fold of amnion devoid of Wharton jelly
Velamentous cord insertion
92
some of velamentous fetal vessels run in lower uterine segment unprotected by Wharton jelly; traverse within fetal membranes on or near the region of the internal cervical os; easily compressed and prone to rupture occurs
vasa previa
93
fetal morbidity of vasa previa with intact membranes
50-60%
94
fetal morbidity of vasa previa with ruptured membranes
70-100%
95
umbilical cord vessels lose Wharton jelly before entering chorionic plate; vessels exposed to external trauma
furcate insertion
96
characterized by discordant fetal size, with polyhydramnios around larger twin and severe oligohydramnios associated with smaller "stuck" twin
twin-twin transfusion syndrome
97
echolucent area within umbilical cord with yolk sac defined as separate structure
first trimester cystic cord masses
98
The fetus is more likely to be abnormal if an umbilical cyst is located near ________ or persists between ___ weeks gestation.
placental or fetal extremity
12
99
result from transient fluid accumulation because of coiling process or herniation of bowel interfering with fluid exchange within cord
umbilical cord cyst
100
Umbilical cord cysts are defined as either _____ or _____.
true cysts
pseudocysts
101
derviced from embryonic remnants of the allantois and omphalomesenteric duct; have no increased risk of chromosomals anomalies; represent vestigial patency of an embryonic structure; located near cord insertion into fetal abdomen
true cysts
102
have no epithelial lining; represent localized edema of Wharton jelly or aneurysm of umbilical artery or vein; positive association with structural and chromosomal abnormalities trisomes 18 and 13
pseudocysts
103
extremely rare benign tumors; also referred to as angiomyxoma, myxangioma, hemangiofibromyxoma, myxosarcoma
hemangiomas
104
fusiform swellings in cord with presence of antiomatous nodule; usually located near placental insertion of cord; often surrounded by localized cystic degeneration and edema of Wharon jelly distinct from tumor
hemangioma
105
benign lesions; very rare; may contain tissues derived from all three germ cell layers
teratomas
106
disorganized polymorphic appearance; complex umbilcal mass containing cystic areas, solid components, and internal calcifications
teratomas
107
result of either inadvertent laceration at time of amniocentesis or intentional mechanical penetration of umbilical vein during cordocentesis
hematoma
108
extremely rare; high perinatal mortality; echogenic material within lumen of blood vessel; single artery umbilical cord with an additional collapsed third vessel
umbilical artery and vein thrombosis with occlusion
109
when physiological herniation of midgut into proximal segment of umbilical cord does not resolve by 14th week
umbilical hernia
110
small, irregular echogenic soft tissue mass identified in base of umbilical cord
umbilical hernia
111
described as having umbilical cord loop around neck of fetus one or more times; appear and disappear throughout pregnancy
nuchal cord
112
presence of cord lying around 3 of 4 sides
nuchal cord
113
umbilical cord presenting part
funic or cord presentation
114
may lead to prolapse of cord during active labor
funic or cord presentation
115
defined as presentation of umbilical cord in advance of fetal presenting part during labor
cord prolapse
116
occurs when fetus actually passes through a loop or loops of cord
true knot
117
"cloverleaf" pattern of cord
true knot
118
number of complete coils per centimeter
umbilical coiling index
119
Normal umbilical cord index is on average _____
.02 coils/c m
120
There is an average of _____ coils in cord
10-12
121
Hypocoiled or undercoiled cords umbilical cord index
0.1 coils/cm
122
hypercoiled or overcoiled cords umbilcal cord index
0.3 coils/cm
123
"mass of umbilical cord"
cord entanglement
124
notch in umbilical cord artery flow velocity waveform may identify pregnancies at immediate risk for :
cord accidents
125
localized narrowing of cord with disappearance of Wharton jelly; associated torsion of cord or thickening of vessel walls with narrowing of lumen; often occurs with long umbilical cords and hypercoiled cords and in highly active fetuses
stricture
126
The placenta increases in both _____ and ______ as gestation processes.
volume
thickness
127
The normal placental thickness is generally between __ and __ cm.
2
4
128
A _______ is a connected bridge of placental tissue.
bilobed placenta
129
A _______ is a mass of placental tissue with a location distant from main placenta/
succenturiate lobe
130
Placental extension beyond the chorionic plate with attachment of the placental membranes to the fetal surface of the placenta describes both ______ and ______ placents.
circummarginate
circumvallate
131
Implantation of the placenta within 2 cm of the internal cervical os is considered a _____.
;low-lying placenta
132
The term _____ refers to an abnormal implantation of the placenta into the uterine wall.
MAP
133
A history of prior c-setion increases the risk of ______ development.
placenta accretac
134
Anechoic structures inferior to chorionic plate with real-time imaging of swirling jets are normal ______.
placental lakesy
135
Hypoechoic _______ are a normal finding in the placenta.
fibrin deposits
136
Massive subchorionic hematoma and thrombis of the placenta is a rare occurrence called a _____.
Breus mole
137
_____ has an association with placental infarction.
IUGR
138
Large chorioangiomas, vascular malformations of the placenta, have an association with _______
serious fetal complications
139
______ has a limited diagnosis with ultrasound.
placental abruption
140
_______ is the rupture of fetal membranes with potential entrapment of fetal parts.
amniotic band syndrome
141
_______ are extra tissue outside the amniotic sac without fetal entrapment.
Uterine synechiae
142
_________ mimics a molar pregnancy.
placental mesenchymal dysplasia
143
The average umbilical length is ___ cm.
55
144
______ covers the outside of the umbilical cord.
Wharton jelly
145
An umbilical cord with a ____ is associated with an increased incidence of chromosomal anomalies.
SUA
146
Umbilical vein curvature to the left side of the fetal abdomen indicates a possible _______
persistent right umbilcal vein
147
An ______ is a focal dilatation of the intra-abdominal umbilical vein that measures greater than 9 mm.
umbilical cord varix
148
The umbilical cord may be absent or extremely short in ______ and _____.
limb-body wall complex
body stalk anomaly
149
Abnormal cord insertions into the fetal abdomen are caused by either an ______ or ______.
ompalocele
gastoschisis
150
Abnormal cord insertions into the placenta include ______, _____, _____, and ______.
marginal insertion
velamentous insertion
vasa previa
furcated insertion
151
Cysts of the umbilical cord can be either ____ cysts or ____.
true cysts
pseudocysts
152
______ is instrumental in demonstrating a nuchal cord.
Color Doppler
153
______ occurs at birth if the cord presents before the fetus
cord prolapse
154
Monochorionic/ monoamniotic twins have a significant risk for _______.
umbilical cord entanglement
155
Umbilical cord torsion can result in ____ of the umbilical cord
stricture
156
Placental hydrops produces a:
thick placenta with a "ground-glass appearance"
157
A "jelly-like" placenta is associated with:
IUGR
158
A succenturiate placenta:
a. has increased frequency in primigravidas
b . is ring shaped
c. most often have velamentous umbilical cord insertion
d. is edematous
c
159
Circumvallate placental tissue is:
a. flat and noted on approximately 20% of placentas
b. associated with a thickened rolled chorioamniotic membrane
c. extremely rare, 1:20,0000 to 40,000 pregancies
d. prone to fetal macrosomia
b
160
Risk factors for placenta previa include all except:
a. previous c section
b. multiple gestations
c. previous elective abortions
d. hypertension
d
161
A placenta is considered low-lying if the inferior margin is:
within 2 cm of the internal os
162
The most infiltrative form of placenta accreta is:
percreta
163
Attachment problems of the placenta are known as all except:
a. morbidly adherent placenta
b. placental attachment disorder
c. abnormally invasive placenta
d. infiltrative myometrial placenta
d
164
Placental infarction is:
a. visualized at the fetal placental surface
b. owing to obstructed spiral arteries
c. multiple hemorrhages into placental lakes
d. a factor in macrosomia
b
165
A benign vascular malformation of the placenta is a:
a. teratoma
b. septal cyst
c. lacunae
d. chorioangioma
d
166
Premature separation of all or part of the placenta from the myometrium is:
abruption
167
Linear, extra amniotic tissue projecting into the amniotic cavity is noted often in pregnant women with a history of:
uterine curettage
168
Amniotic band syndrome is a condition that:
a. involves free-floating membrane
b. is a result of rupture of the amnion without rupture of the chorion
c. is not revealed in the third trimester
d. involves the uterine septum
b
169
A condition of pregnancy where the trophoblastic cells produce excessive amounts of beta-human chorionic gonadotropin is:
molar pregnancy
170
SUA is associated with all except:
a. cardiovascular malformation
b. central nervous system defects
c. musculoskeletal abnormalities
d. skeletal dysplasia
d
171
PRUV, a common vascular variant, describes:
open right portal vein
172
TTTS is caused by:
monochorionic twin pregnancies sharing a placenta with anastomoses between the umbilical vessels
173
Prenatal management of known umbilical pseudo and true cystss:
a. is not necessary because resolution is imminent
b. typically refers to MRI for evaluation
c. involves serial ultrasound examinations
d. displays echogenic characteristics near the placental insertion
c
174
Cord prolapse is defined as:
presentation of the umbilical cord in advance of the fetal presenting part during labor and delivery
175
Subamniotic cysts or subamniotic hematomas result from rupture of ______ close to the umbilical cord insertion into the placenta.
chorionic (fetal) vessels
176
Selective loss of placental parts and growth of other parts is known as _______.
trophoblastic trophoism
177
The ring-shaped annular placenta is related to postpartum _____ mostly owing to poor separation.
hemorrhage
178
Acute placental abruption hemorrhage appears highly ______ on ultrasound
echogenic
179
Choriocarcinomas appears as _______ , echogenic, and _______ masses.
heterogeneous
hypervascular
180
Placenta accreta is mostly located in the _____, _____ uterine segment.
anterior implantation
lower
181
Visualization of multiple ______ are highly suggestive of placenta accreta.
vascular lacunae
182
Multiple chorioangiomas or those larger than ___ cm are related to maternal and fetal complications
5
183
Early detection of fetal anemia is possible where chorioangioma is suspected, through Doppler measurements of the _____.
middle cerebral artery
184
Extremely hydropic and swollen chorionic villi are frequently related to _____.
gestational trophoblastic disease
185
Molar pregnancies have a characteristic ______ appearance with uterine cavity _____.
heterogeneous, echogenic mass
distention
186
The most common reason for emergency postpartum hysterectomy is a ______.
morbidly adherent placenta
187
A coexisting fetus with an enlarged thickened placenta revealing multiple small cystic spaces is a _____.
partial hydatidform mole
188
The placenta may sonographically appear thickened in some cases of IUGR, with patchy areas of ______ and abnormal texture/
hypoechogenicity
189
A two-vessel umbilical cord reveals the presence of a single umbilical _____ and is sometimes associated with congenital anomalies such as cardiovascular malformations, central nervous system defects, _______ or genitourinary defects, and ______ malformations.
artery
gastrointestinal
musculoskeletal s
190
The umbilical vessel abnormality seen with conjoined twins is ______ vessels.
supernumerary
191
Maternal cocaine abuse leads to the fatal condition _______.
body stalk anomaly
192
Velamentous insertion is more frequent in _____ gestations.
multiple
193
Compressed umbilical cords place the fetus at risk for _______ or ______ compromise.
fetal hypoxia
circulatory
194
A successful method of identifying a nuchal cord is imaging using color Doppler technology.
Color Doppler
195
The normal placenta typically increases in _____ and ____ with advancing gestation.
thickness
volume
196
______ is sometimes used to describe the appearance based on the amount of placental calcifications and degree of maturation.
placental grading
197
Placental size is expressed in terms of thickness in the midportion of the placenta and should be approx ____ cm.
2-4
198
The placenta may appear thickened with patchy areas of hypoechogenicity and an abnormal texture
IUGR
199
"jelly like placenta"
IUGR
200
A ________ is the presence of one or more small accessory lobes that develop in the membranes at a distance from the periphery of the main placenta. It is connected to the main placenta by vessels within the membrane.
succenturiate lobe
201
A _______ is distinguished from a bilobed placenta by a bridge of tissue that communicates between the two lobes and the cord insertion is in the chorionic tissue of the bridge.
succenturiate lobe
202
Retained accessory lobes can be associated with ______ and _____.
postpartum hemorrhage
infection
203
Succenturiate lobes are associated with an increased incidence of ______ insertion of the umbilical cord and _____, which are conditions that have significant maternal and fetal complications.
velamentous
vasa previa
204
_______ refers to a ring-shaped placenta that attaches circumferentially to the myometrium and can be associated with antenatal or postpartum hemorrhage.
annular placenta
205
the placenta extending beyond the limits of the chorionic plate with attachment of the placental membranes to the fetal surface of the placenta, inward from the edge, rather than to the underlying villous placenta margin
placenta extrachorialis
206
fetal membrane insertion is flat
circummarginate
207
thickened rolled chorioamniotic membranes peripherally
circumvallate
208
associated with:
increased risk of maternal bleeding
placental abruption
premature labor and delivery
IUGR
prenatal death
fetal anomalies
complete circumvallation
209
implantation of the placenta in the lower part of the uterus covering the internal cervical os, thus delivering before the fetus
placenta previa
210
Four categories of placenta previa
complete previa
partial previa
marginal previa
low lying placenta
211
inferior margin of placenta covers internal os
Complete previa
212
inferior margin of placenta partial covers internal os
partial previa
213
inferior margin of placenta is on the edge of the internal os
marginal previa
214
inferior margin of placenta is within 2 cm of internal os
low-lying placenta
215
an abnormal implantation of the placenta into the uterine wall
morbidly adherent placenta (MAP)
216
chorionic villi adhere directly to the myometrium but do not invade the myometrium
placenta accrete
217
chorionic villi invade the myometrium
placenta increta
218
chorionic villi invade through the myometrium into the uterine serosa and potentially into surrounding tissues
placenta percreta
219
most common reason for an emergency postpartum hysterectomy
morbidly adherent placenta (MAP)
220
Sonographic markers for morbidly adherent placenta in the first trimester
gestational sac implantation in the lower uterine segment
multiple irregular vascular spaces within the placental bed
cesarean scar implantation of the gestational sac
221
irregular anechoic structures within the placental parenchyma that are found beneath the chorionic plate
placental lakes
222
end result of intervillous and subchorionic thrombosis, which results from pooling and stasis of maternal blood in the perivillous and subchorionic spaces
fibrin deposition
223
hypoechoic lesions in the subchorionic area or within the placental mass, or as linear echogenic streaks
fibrin deposition
224
intraplacental area of hemorrhage and clot
intervillous thrombosis
225
hypoechoic placental lesions of varying size that may contain linear echogenicities representing fibrin deposits
intervillous thrombosis
226
obstruction of the spiral arteries; usually found at the periphery of the placenta
placental infarction
227
associated with retroplacental hemorrhage in up to 25% of term placentas
placental infarction
228
rupture of chorionic (fetal) vessels close to the umbilical cord insertion into the placenta
subamniotic cysts or subamniotic hematomas
229
most often found near the placental cord insertion under the thin amniotic layer covering the chorionic plate
subamniotic cysts or subamniotic hematomas
230
Two primary nontrophoblastic tumors of the placenta
chorioangiomas
teratomas
231
benign vascular malformation of the placenta arising from primitive chorionic mesenchyme
chorioangioma
232
associated with:
elevated maternal serum alfa-fetoprotein
beta-human chorionic gonadotropin levels
chorioangioma
233
contain arteriovenous shunts that lead to severe fetal complications
chorioangioma
234
well-circumscribed hyperechoic or hypoechoic ovoid mass with increased vascularity protruding from the fetal surface of the placenta near the cord insertion
chorioangioma
235
very rare, usually benign but can be highly malignant, may contain structures derived from the three germ cell layers
teratomas
236
complex mass of the placenta with cystic and solid components; calcifications may be present
teratomas
237
