placenta, umbilical cord, amniotic fluid and membrane pathology
What is the difference between a high pressure & a low pressure bleed of the placenta?
"Low pressure" bleed rupture or tear of marginal veins associated with little placenta detachment High pressure bleed results from rupture of the spiral arteries most risky form of abruption
What is the difference between Potter's syndrome and Potter's sequence?
"Potter sequence" Deformities caused by oligohydramnios. "Potter syndrome" Deformities caused by oligohydramnios if caused by bilateral renal agenesis.
What is the difference between placenta accrete, increta & percreta?
-Accreta (vera) Chorionic villi are attached to, but do not invade the myometrium with absence of the decidua basalis Least invasive form -Increta chorionic villi infiltrate the myometrium, but not the serosa hysterectomy may be required -Percreta villi penetrate completely through the uterine myometrium to the serosal surface of the uterus, and potentially invade the surrounding maternal organs
Which of the following demonstrate blood flow on color Doppler? Chorioangioma Hemangioma Hematoma Thrombus
-Chorioangioma Benign hypervascular malformation + Color Doppler Arises from chorionic tissue -Hemangioma
What are 2 treatment options for oligohydramnios?
-Maternal hydration has been shown to improve the amniotic fluid for patients with oligohydramnios and normal amniotic fluid volumes, except in the case of fetal anomalies or PROM. -amnio-infusion infusion of saline solution into the amniotic cavity does not "treat" the underlying cause of oligohydramnios may relieve or prevent cord compression
What is the sonographic appearance of posterior urethral valves? Bladder Abdomen Fluid
-bladder = dilated -abdomen = over distended abdominal wall -fluid = oligo
What are causes of placentomegaly? What are the 2 primary causes?
-maternal causes diabetes (all types) - "primary cause" anemia -fetal causes any cause of fetal hydrops (fluid overload - text) isoimmunization - RH incompatibility is a "primary cause"
How will the presence of an abdominal wall defect affect the abdominal circumference of the fetus?
AC measurement may not be accurate may be small, depending on the size of the defect
What is another term used to describe a low pressure bleed? - this term is commonly used in the 1st trimester.
Also referred to as a "subchorionic hematoma
Which is more concerning, amniotic bands or amniotic sheets (synechia)? Why?
Amniotic band syndrome - thin membrane strands constriction of the fetus due to disruption of the amnion fetus may adhere to and fuse with the chorion - entrapment of fetal parts (- blood flow) color flow not typical
What is the cause of posterior urethral valve obstruction?
Bladder outlet obstruction produced by a membrane within the posterior urethra
What are the structural causes of polyhydramnios?
CNS (central nervous system) disorders depressed swallowing cleft palate anencephaly chromosomal abnormalities
What is the most common benign placental tumor?
Chorioangioma
What is the term to describe an abnormal attachment of the placental membrane to the fetal surface of the placenta? A rolled edge may be visualized on ultrasound.
Circumvallate placenta
"true" umbilical cord cyst What is the origin? Where is it located? Is it associated with chromosomal anomalies?
Close to the fetal cord insertion Centrally located between the umbilical vessels Often associated with spontaneous resolution
Is placenta accreta associated with increased vascularity? If so, where?
Color Doppler can identify prominent uterine vessels (increased vascularity) at abnormal insertion site.
Which abdominal wall defect will have a high AFP? Why?
Defect is not covered by a membrane bowel loops in direct contact with amniotic fluid associated with elevated AFP/MSAFP levels
What are the clinical associations of a velamentous cord insertion?
Fetal IUGR Small percentage of pregnancies may be complicated by hemorrhage related to tearing of the unprotected vessels, especially during labor & delivery
If a chorioangioma is large (> 5cm), what maternal & fetal problems may occur?
Fetal anemia - MCA Doppler useful in DX & management Polyhydramnios Hydrops Fetal cardiomegaly IUGR Preeclampsia Preterm labor Elevated maternal serum alpha-fetoprotein
What is the most common "fetal" cause of polyhydramnios?
GI problems are the most common "fetal" cause of polyhydramnios.
What is the position of the fetal gallbladder in relation to the umbilical vein and stomach?
Gallbladder lies between the RT umbilical vein & the stomach
Gastroschisis & omphalocele - which defect is covered with a membrane & which is not?
Gastroschisis = not covered by membrane omphalocele = covered by a membrane
At what gestational age would a grade 3 placenta be of concern for premature maturation? Why would premature maturation of the placenta be a concern?
Grade 3 placenta before 34 weeks is a sign of premature maturation of the placenta.
Hematoma versus thrombosis of the umbilical cord - how are they different? Where are they each located?
Hematoma Abnormal localized collection of blood in which the blood is usually clotted or partially clotted.Caused by a break in the wall of a blood vessel Occurs on the "outer wall" of the vessel. Thrombosis Formation or presence of a blood clot within a blood vessel - vein or artery. Thrombosis primarily occurs within the umbilical vein
What is a predisposing condition associated with placenta accreta? What common surgical procedure is associated with placenta accreta?
Implantation of the placenta over the scar is an important predisposing condition Hysterectomy ?
If a small omphalocele contains only small bowel, what may that indicate?
Increased risk of chromosomal anomalies noted with: omphaloceles containing only bowel, without liver small omphalocele containing only small bowel when oligohydramnios or polyhydramnios are present
Which classification/s of placenta accreta may put the patient at risk for having a hysterectomy?
Increta Percreta
In the normal fetus, which umbilical vein remains open?
Left umbilical vein remains open
What is the term for an umbilical cord that inserts into the edge of the placenta?
Marginal cord OR battledore placenta
What type of umbilical cord insertion has an insertion site within 2 cm of the placental edge?
Marginal cord OR battledore placenta
Why is the fetal bladder shaped like a "key hole" when the fetus has a posterior urethral valve obstruction?
Marked dilatation of posterior urethra and bladder (keyhole appearance)
What is a keyhole bladder, and what fetal abnormality is it associated with?
Marked dilatation of posterior urethra and bladder (keyhole appearance), & bladder wall thickening. Most common cause of urinary obstruction in male infants - identify fetal sex. GU (genitourinary) abnormality
What are 2 maternal causes of a thin placenta?
Maternal diabetes mellitus (vascular associations) intrauterine infection
What symptoms are associated with polyhydramnios?
May compress Organs Vascular structures May cause maternal pain hydronephrosis SOB (shortness of breath)
Why is it important to evaluate the presence of an omphalocele after 12 weeks GA?
Normal umbilical cord herniation is noted between 8-12 weeks GA do not confuse normal umbilical cord herniation with omphalocele follow-up after 12 weeks GA
What is the most common cord entanglement in the fetus?
Nuchal Cord
What is a false knot of the umbilical cord?
Occurs when blood vessels are longer than the cord vessels fold on themselves and produce nodulations on the surface of the cord Blood flow is not completely constricted; constriction may occur secondary to fetal activity & tension on the cord with fetal movement
What problems are associated with a short umbilical cord?
Oligohydramnios Restricted amniotic space Fetal distress Cord compression Intrinsic fetal anomaly
What does the combination of oligohydramnios & absence of the fetal bladder suggest?
Oligohydramnios with no evidence of fetal bladder suggests a bilateral renal abnormality
What are the causes of oligohydramnios?
PROM - premature rupture of membranes Post term pregnancy GU abnormalities Chromosomal abnormalities IUGR-intrauterine growth restriction (smallfetus-lowfluid) TTTS Maternal hypertension
What is the most dangerous form of placenta accreta?
Percreta
Is the prognosis good for an umbilical vein thrombosis?
Poor prognosis with umbilical vein thrombosis Umbilical cord thrombosis is a potentially fatal complication not always fatal
What is a GU abnormality that occurs in male fetuses?
Posterior urethral valves
What is placental abruption?
Premature (before term delivery) detachment of the placenta from the endometrial surface.
Does a normal sonographic appearance exclude the possibility of a placental abruption?
Presence of a normal ultrasound exam does not exclude the possibility of placental abruption.
What are the risk factors for severe placental abruption?
Previous H/O abruption Trauma H/O placenta previa Uterine fibroid Maternal hypertension - seen in 50% of severe abruptions Maternal vascular disease Short umbilical cord Methamphetamine use (cocaine) Cigarette smoking Maternal teratogen use AMA Unexplained increased MSAFP
What is the term for an umbilical cord presentation?
Prolapsed Umbilical Cord
Which direction does the right umbilical vein curve?
RUV curves toward the left sided stomach rather than toward the liver
In TTTS, which twin will have poly, and which will have oligo?
Recipient twin may develop hydrops and polyhydramnios Donor twin becomes anemic and growth restricted with oligohydramnios
At what gestational age is detachment of the placenta from the maternal wall called placental abruption?
S/P 20 weeks GA
What is a leading cause of perinatal mortality?
Severe abruption
What is the most common umbilical cord abnormality?
Single Umbilical Artery - "SUA" or 2 Vessel Cord
What are the symptoms of placental abruption?
Small hematomas cause subtle symptoms: mild abruption - painless vaginal bleeding Large abruptions cause acute symptoms: abdominal pain vaginal bleeding tense uterine wall maternal shock fetal distress IUGR preterm labor
Which umbilical vessel is most commonly associated with thrombosis?
Thrombosis primarily occurs within the umbilical vein.
Thrombosis - which vessel is more likely to develop a blood clot, the artery or the vein? What is the appearance of the vessel/s?
Thrombosis primarily occurs within the umbilical vein. Usually demonstrates hyperechoic vessels
Where in the placenta are chorioangiomas located?
Usually near the cord insertion site and just below the chorionic plate protrudes from the fetal side of the placenta
What type of a cord insertion is not protected by Wharton's jelly, and does not insert into the placental disk?
Velamentous /membranous cord insertion
What are the causes of a 2VC?
aplasia - incomplete or faulty development of an organ atrophy of one of the umbilical arteries in early development thrombosis in one of the arteries
What type of placental mass appears as a solid or complex circumscribed mass that protruded from the fetal surface of the placenta? Does this mass demonstrate blood flow?
chorioangioma , + color Doppler
How is placenta accrete classified?
classifications based on depth of invasion
Why is the umbilical cord coiled/twisted?
coiling protects against compression of the vessels coiling is thought to be related to fetal activity absence of UM cord twisting is an indirect sign of decreased fetal movement
What technique can you use to locate fetal kidneys when oligohydramnios is present?
color Doppler to identify the renal arteries
What is/are the complication/s associated with a prolapsed umbilical cord?
compression of the cord, reducing or cutting off the blood supply to the fetus .
What types of pathology is a 2VC associated with?
congenital anomalies chromosomal anomalies autosomal trisomies cardiac anomalies renal anomalies IUGR premature delivery perinatal death Occurs in 6.45% of diabetic pregnancies
Placentomegaly and thin placenta both are associated with maternal diabetes. What specific diabetic issue would be the cause of a thin placenta?
diabetes mellitus (vascular associations)
How is placental abruption diagnosed?
diagnosis is usually made clinically!
What clinical lab work may be elevated in the presence of placenta accreta?
elevated MSAFP
Are there complications associated with a nuchal cord? If so, what are they?
fetal heart deceleration meconium stained amniotic fluid babies requiring resuscitation
Which of the 2 defects typically has a better prognosis, omphalocele or gastroschisis?
gastroschisis
What are the effects of prolonged oligohydramnios?
interferes with fetal lung development, resulting in pulmonary hypoplasia.
What is the most serious consequence to the fetus when prolonged oligohydramnios occurs?
interferes with fetal lung development, resulting in pulmonary hypoplasia.
Is it more common to have higher or lower amniotic fluid levels close to term (due date)?
lower
Under what conditions is it more likely for the fetus to have a true knot/s of the umbilical cord?
monoamniotic multiple gestations long umbilical cord polyhydramnios
What amniotic fluid abnormality are Potter's syndrome and Potter's sequence associated with?
oligohydramnios.
Which abdominal wall defect has a strong association with fetal anomalies, omphalocele, gastroschisis or umbilical hernia?
omphalocele
What are the 2 most common anterior abdominal wall defects?
omphalocele gastroschisis
Where does the umbilical cord typically insert when the fetus has An omphalocele Gastroschisis
omphalocele herniation of intraabdominal structures into the base of the umbilical cord at the level of the cord insertion Umbilical cord inserts into the defect rather than into the abdominal wall. Gastoschisis mass usually found to the right of, and adjacent to the fetal cord insertion normal cord insertion
What placental pathology is described as having a "swiss cheese appearance"?
placenta accreta
What is the term to describe a placenta that is thin, and covers the periphery of the chorion?
placental membranacea
What problems are associated with a long umbilical cord?
polyhydramnios nuchal cord true cord knots vascular compromise & fetal distress fetal distress vasa previa prolapsed cord
What are the fetal risks associated with oligohydramnios?
pulmonary hypoplasia most serious consequence skeletal (limb positional) abnormalities - club feet, contractures, hip dislocation facial deformities/abnormal facies - flattened nose, low set ears & recessed chin umbilical cord compression & fetal asphyxia (lack of oxygen) adherence of membranes to fetus fetal infection (PROM)
What organ/structure is always found in the herniation of gastroschisis?
small bowel is always found in the herniation of gastroschisis
Why will a fetus with IUGR have low amniotic fluid?
small fetus results in decreased urine output
Is a 2VC usually associated with other fetal pathology?
yes
