Placenta and umbilical cord Flashcards
1
Q
Placenta is formed by the
A
decidua basalis and decidua frondosum
2
Q
Physiology of placenta
A
- vital support organ for developing fetus
3
Q
major functioning unit of placenta
A
chorionic villus
- contains intervillous space
4
Q
maternal blood enter the
A
intervillous space
5
Q
Placenta Functions
Respiration
A
- oxygen in maternal blood passes through plac into fetal blood
- co2 returns through the plac to maternal blood
6
Q
Placental Function
Nutrition
A
pass from maternal blood through plac to fetal blood
7
Q
Placenta Function
Excretion
A
- wast products cross from the fetal blood through the plac to maternal blood
8
Q
Placenta Function
Protection
A
provides a barrier between the mother and fetus, protecting the fetus from maternal immune rejection
9
Q
Placenta Function
Storage
A
carbs, proteins, calcium, and iron are stored in plac and released into fetal circulation
10
Q
Placenta Function
Hormone Production
A
produces hCG, estrogenm and progesterone
11
Q
Plac Size
A
- varies with gestational age
- 2-3 mm thickness
- should exceed 4 cm
12
Q
Normal sono appearence of placenta in 1st trimester
A
thickened area of hyper gestational age
13
Q
Normal sono appearence of placenta in 2nd and 3rd trimester
A
- smooth, homogeneous medium-gray structures
- smooth border and edges
- hyperechoic chorion plate
14
Q
cystic areas directley behind chorion plate
A
fetal vessels
15
Q
plac may be located
A
ant, post, fundal, rt later, and lt lateral
16
Q
plac may be implanted over or near
A
cervical os (previa)
17
Q
grading is dependent on
A
echogenicity attributed to calcium and fibrous deposition with advancing age
18
Q
cause premature maturation of plac
A
maternal hypertensions, smoking, iugr, multifetal gestation
19
Q
- no calcification
- smooth basal and chorionic plate
- 1st and early second
A
Grade 0
20
Q
- scattered calification throughout the plac
- most common up until 34 w
A
Grade 1
21
Q
- calcifications along basal palte
- chorionic plate becomes slightly lobular
A
Grade 2
22
Q
- marked calcifications
- distinct hyper loculations extending from chorionic to basal plate
- abnormal before 34 w
A
Grade 3
23
Q
- in front of fetus relative to birth canal
- primary cause of painless vag bleeding in 3rd trim
A
Plac previa
24
Q
plac previa risk factors
A
advanced maternal age, multiparity, previous c section, theraputic abortion, or closely spaced pregnancies
25
plac previa complications
premature delivery, life-theratening maternal hemorrhage, increased risk of plac accretta, stillbirth, and iugr
26
Plac previa complete
- painless vag bleeding
| - placenta cover entire cervical os
27
plac pervia partial/ incomplete
- painless vag bleeding
| - placenta covers one side of cervical os
28
plac previa marginal
- asymptomatic, painless vag bleeding
| - edge of plac covers one side of the cervical os
29
plac previa low-lying
- asymptomatic
- painless vag bleeding
- edge of plac lies close by doesnt abut cx os, 2 cm
30
plac vasa previa
- bleeding
- cord compression
- prolapsed cord
- transverse fetal lie
- fetal vessels cross over internal os
31
Plac abruption
- premature plac detachment
| - clinical findings include severe pelvic pain and vag bleeding
32
plac abruption risk factors
materal hypertension, smoking, diabetes, trauma, plac previa, and short umbilical cord
33
plac abruption sono findings
- hypoechoic retroplacental mass
- plac thickening
- well defined margins
- sub amniotic or preplacental locations are rare
34
plac accreta
- chorionic villi of the plac are indirect contact with uterine myo
- attributed to complete or partial absence of the decidua basalis
35
plac accreta risk factors
multiparity, plac previa, and previous c section
36
plac accreta sono findings
- obscured or absent retroplacental complex
| - numerous plac lakes
37
plac increta
- plac invades the uterine myo
38
plac increta sono findings
extension of villi into myo
39
plac percreta
placental vessels invade uterine serosa and bladder
40
plac percreta sono findings
extension of villi outisde of ut
41
amniochorionic seperation
| amnion
separated from fetal surface of plac but cant separate from umbilical insert site
42
amniochorionic seperation
| chorion
separated from endo lining but cant separate from plac edge
43
amnionchorionic separation
- localized fluid between fetal side of plac and amniotic membrane
- membrane can move
44
Battledore plac
cord insert into end margins of plac
45
battledore plac sono findings
insertion of cord into end margin of plac
46
calcifications
- sign of mature plac
| - assoc with smoking or thrombotic disorders
47
calcification sono findings
- hyper focus within the plac tissue
| - posterior shadowing
48
circumvallate plac
- abnormal plac shape in which membrane insert away from plac edge toward center
- increase risk for sbruption, iugr, premature labor, perinatal death
49
fibrin deposits
- more commonly located along the subchorionic region of plac
- attributed to regulation of interbillous circulation
50
fibrin deposits sono findings
- hypo area beneath chorionic plate of plac
| - traingular or rectangle in shape
51
intervillous thrombosis
- presence of thrombus within the intervillous space
- occurs in 1/3 pregnancies
- little risk to fetus
52
intervillous thrombosis sono findings
- anechoic or hypo intraplacental mass
| - nonvascular
53
placental infarct
- results of ischemic necrosis
- occurs in 25% of pregnancies
- no clinical risk when small
54
placental infarct sono findings
- hypoechoic focal placental mass
| - calcification may occur
55
placental lakes sono findings
- anechoic area with internal blood flow
56
placentomalacia
- small plac
- iugr
- intrauterine infection
- chromosomal abnormalities
57
placentomegaly
- primary causes include maternal diabetes and rh sensitivity
- assoc with maternal anemia, twin-twin transfusion, fetal anomalies and intrauterine infection
58
placentomegaly sono findings
- max thickness > 5 cm
- heterogeneous texture assoc with tripoloidy, molar pregnancy, or hemorrhage
- homogeneous texture assoc with anemia, hydrops, and eh sensitivity
59
succenturiate plac
- results of the lack of adj chorionic villi to atrophy
- approx 5% pregnancies
- increased risk of velamentous cord and vasa previa
60
succenturiate plac sono findings
- additional plac tissue adh to main plac
| - connected to body of plac by blood vessels
61
Chorioangioma
- placental hemangioma
- arises from chorionic tissue of amniotic surface of plac
- fetaus demonstrates distress owing to vascular shunting from normal lac to hemangioma when large
62
choriangioma metastases to
lung, spleen, kidney, intestines, liver and brain
63
chrioangioma sono findings
- enlarge plac
- circular, solid hypo mass protruding from chorionic plate
- usually occur at umb insert
- poly, hydrops, iugr
64
choriocarcinoma
- malignant form of trophoblastic disease
| - 50% are preceded by a molar pregnancy
65
choriocarcinoma sono findings
- hypo intraplac mass
66
gestational trophoblastic disease
- molar pregnancy
- complete molar pregnancy may cevelop into choriocarcinoma
- partial mole carries little malignant potential
67
Gestational trophoblastic disease sono findings
- inhomogeneous uterine texture
- various sized cystic structures within plac
- coexsist with decrease in afi
68
Umbilical cord normally inserts into
the center of the plac and midline of anterior abd wall of fetus
69
Umbilical vein carries
oxygenated blood
70
umbilical arteries return
venous blood back into plac
71
Umbilical cord is formed by the
fusion of the yolk sac and body stalk (allantoic ducts)
72
What covers the umbilical cord and blends into the fetal skin at the umbilicus?
amniotic membrane
73
Wharton's jelly
composed of one vein and two arteries surrounded by myxomatous connective tissue
74
Umbilical Vein
- formed by the confluence of chorionic vein of plac
| - enters umbilicus and joins the left portal vein of liver
75
Umbilical Arteries
- contiguous with hypogastic arteries on each side of the bladder
- exits umbilicus
- return venous blood from the fetus back to the plac
- demonstrate low resistance blood flow with continuous diastolic flow
76
length of umbilical cord in 1st trim equals
crown rump length
77
length during second and third trim
40-60 cm
78
Diameter of the umbilical cord
79
Umbilical vein diameter
80
cyst of umbilical cord
- normal findings in 1st trim
| - 50% of cases assoc with fetal anomalies in 2nd and 3rd trim
81
cyst of umbilical cord sono appearence
- nonvascular anechoic enlargement
82
false knot of umbilical cord
coiling of blood vessels, giving the appearance of knots
83
false knot of umbilical cord sono findings
blood vessels folding over on themselves mimicking umbilical nodules
84
long cord
-cord >80 cm
85
long cord sono findings
nuchal cord
poly
true umbilical cord knot
vasa previa
86
nuchal cord
- cord completely surrounds fetal neck with more than one loop
- fetus will turn in and out of umbilical cord throughout the pregnancy
87
nuchal cord sono findings
- two or more complete loops of cord around neck
| - flattening of cord
88
prolapsed cord
cord preceds the fetus in the birthing process
89
prolapsed cord sono findings
presence of cord before shortthe presenting fetal part
90
short cord
91
short cord sono findings
- limited fetal movement
- inadequate fetal descent
- cord compression
- oligo
92
single umbilical artery is more common in
multiple gestations
93
single umbilical artery demonstrates
both single and double umbilical arteries within same cord
94
single umbilical artery increases risk of
assoc fetal anomalies and iugr
95
single umbilical artery is assoc with
malformations of all major organ systems and chromosomal anomalies
96
single umbilical arteries sono findings
- two vessels of similar size within umbilical cord
- umbilical artery transverse dia >4 mm
- straight, noncoiled
97
Thrombosis of umbilical vessels
- primarily vein
| - higher incidence in diabetic mothers
98
thrombosis of vessels
- absent or abd flow
| - hypoechoic enlargement of 1 or more vessels
99
varix of umbilical vein
- focal dilation of vein
- always intraabdominal
- assoc with normal outcomes
100
varix of umbilical vein sono findings
- intraabdominal focal dilation of vein
| - located between anterior abd wall and liver
101
velamentous cord insert
- umbilical cord insert into membranes before entering the plac
- not protected by Wharton's Jelly
102
velamentous cord insert assoc with
```
preterm labor
abnormal fetal heart pattern
low apgar scores
low birth weight
iugr
```
103
velamentous cord insert sono findings
insert of umbilical cord into membrane adj to edge of plac margin
104
incompetent cervix
- cervical shortening
| - painless
105
decrease in cervical length of > 6mm
increases risk of preterm labor
106
incompetent cervix risk factors
multiple pregnancies
hx of premature labor
previous hx of cervical surgery
107
incompenent cx cervical length
108
dilating of cervical os
> 3 - 6 mm
109
incompenent sono finding
funneling of amniotic fluid into cervical canal
