Study guide test 3 Flashcards
Caudal regression syndrome is commonly found in patients with what?
diabetes
What term defines the appearance of overlapping skull bones that indicates fetal death?
Spalding’s sign
What would fetal hydrops appear like under US and what are the sonographic findings?
scalp edema
pleural effusion
pericardial effusion
ascites
polyhydramnios
thickened placenta
If hydrops is caused by tachycardia, what would the fetal heart rate be?
200-240bpm
If a pregnant woman has a baby, and she is a patient of size, what is there an increased incidence of?
increased incidence of neural tube defects
What is caudal regression syndrome?
lack of development of the caudal spine and cord
What skeletal and central nervous system anomalies are found in infants of diabetic mothers?
caudal regression syndrome
neural tube defects excluding anencephaly
anencephaly with or without herniation of neural elements
microcephaly
When is it considered premature labor?
onset of labor before 37wks gest
Monochorionic twins, what anomaly is it when one twin develops without a heart or upper body?
acardiac anomaly
Twin to twin transfusion syndrome:
exists when there is an arteriovenous shunt within the placenta
arterial blood of one twin is pumped into the venous system of the other
one twin has less blood flow(develops oligo)
one twin has too much blood flow(develops poly)
What is poly-oli sequence?
diamniotic pregnancy: one sac has poly, the other has severe oligo and a smaller twin
What is another name for poly-oli sequence?
stuck twin
Development of conjoined twins occurs how many days after conception?
if division occurs after 13 days
Stuck twin syndrome is usually observed in what weeks?
usually manifests between 16-26wks gest
Diamniotic and dichorionic twin preg demonstrates what sonographic findings?
2 amnions and 2 chorions
What is demonstrated when one fertilized egg division occurs 4-8 days after fertilization?
one chorion and two amniotic sacs (monochorionic diamniotic)
What are the predictors of discordant in the growth of twins?
difference in estimated fetal weight of more than 20%
difference in BPD of 6mm
difference in AC of 20mm
difference in femur length of 5mm
Most frequent cause of nonimmune hydrops:
cardiovascular lesions
What are the advantages of chorionic villi samplings?
it is performed early in preg (10-14wks)
results are available within 1wk
earlier results allow more options for parents
Cordocentesis is more commonly used for what procedure?
guidance for transfusions to treat fetal isoimmunization
What is amniocentesis used for?
first used: to relieve polyhydramnios, Rh isoimmunization, document fetal lung maturity
Why do we perform amniocentesis?
offered to patients who are at risk for chromosomal abnormalities or biochemical disorders
Twins that arise from two separately fertilized ova are what type of twins?
dizygotic
Sonographic findings that suggest chromosomal anomalies include:
Tri 21: nuchal thickness, heart defects, duodenal atresia, shortened femurs, mild pyelectasis, mild ventriculomegaly, echogenic bowel
Tri 18: heart defects, choroid plexus cysts, clenched hands, micrognathia, talipes, renal anomalies, cleft lip and palate, omphalocele, CDH, cerebellar hypoplasia
Tri 13: holoprosencephaly, heart defects, cleft lip and palate, omphalocele, polydactyly, talipes, echogenic chordae tendineae, renal anomalies, meningomylocele, micrognathia
triploidy: hydatidiform placental degeneration, heart defects, renal anomalies, omphalocele, cranial defects, facial defects
Turner’s syndrome: cystic hygroma, heart defects, hydrops, renal anomalies
AFP is found in what fetal structures?
major protein in fetal serum, produced by yolk sac in early gest and later by the fetal liver
found in fetal spine, gastrointestinal tract, liver, and kidneys
High levels of AFP indicate what?
neural tube defects-anencephaly and open spina bifida
What markers does the quad screen evaluate?
AFP, human chorionic gonadotropin (hCG), and unconjugated estriol
What is an abnormality of the number of chromosomes called?
aneuploidy
What is an early noninvasive means of assessing the risk of aneuploidy?
PAPP-A, and beta hCG levels-blood test
Following sono findings of thickening nuchal, shortened femurs, cardiac anomalies, and hydro, what do we look for?
Trisomy 21
Sonographic findings of cranial anomalies, choroid plexus cyst, facial abnormalities, and rocker bottom feet?
Trisomy 18
Holoprosencephaly and proboscis are found in what type of fetus?
Trisomy 13
Secondary to pregnancy include hypertension, coma, seizure in 2nd and 3rd tri represent what?
eclampsia
Large cystic hygroma, hydrops, coartation (arch/ascending, split, b/c of trauma) of the aorta may be seen in a fetus with what condition?
Turner’s syndrome
Pregnancy associated with PAPP-A levels, what do they do?
increase throughout preg
decrease in preg affected by aneuploidy
AFP produced early in gest by what structure?
yolk sac
Common reason for an elevated MSAFP is what?
twin pregnancy
What is the most common aneuploidy condition?
Down’s syndrome (trisomy 21)
An optimal collection site in an amniocentesis is what?
away from the: fetus, central portion of the placenta, and umbilical cord
near the maternal midline to avoid the maternal uterine vessels
MSAFP levels increase with advancing gest age and peak at how many wks gest?
15-18wks gest
Free beta hCG can be assessed in maternal serum in the 1rst tri to evaluate an increased risk of what condition?
Down syndrome
After amnio, sonographer should document what?
cardiac activity
Continuous monitoring with US during amnio is invaluable in cases of what?
oligohydramnios, anterior placental position, and premature rupture of membranes
Fetal death that occurs after the fetus has reached a certain growth that is too large to reabsorb into the uterus is called what?
fetal papyraceus
Low AFP levels have been found in this condition (most common)?
trisomy 21, 18, and 13
What is the picture of the chromosomes called?
karyotyping
Abnormal NT increases fetal risk for what?
tri 13, 18, 21
triploidy
Turner’s syndrome
What is associated with Turner’s syndrome?
cystic hygroma
heart defects
hydrops
renal anomalies
Which is included in 1rst tri maternal serum screening?
PAPP-A
free beta hCG
Conjoined twins: 5 most common types
thoracopagus-joined at thorax
omphalopagus-joined at the anterior wall
craniopagus-joined at the cranium (syncephalus-conjoined twins with one head)
pygopagus-joined at the ischial region
ischiopagus-attached at the buttocks
Autosomal dominant
dominant disorder, condition caused by a single defective gene
usually inherited by 1 parent who is affected
may arise as a new mutation
Autosomal recessive
recessive disorder, caused by a pair of defective genes, one inherited from each parent
25% chance of having a fetus with a disorder
Mosaic patterns
mosaicism:occurrence of a gene mutation or chromosomal abnormality in a portion of an individual’s cells
