Week 2 Fetal & Neonatal Assessment (everything) Flashcards
Fetal growth restriction results from suboptimal uteroplacental perfusion and fetal nutrition caused by different conditions that can be divided into:
(3 answers)
Maternal
Fetal
Placental
(bold in PPT)
Fetal growth restriction results from? (two answers)
suboptimal uteroplacental perfusion and fetal nutrition.
Maternal disorders associated with fetal growth restriction include any condition that can potentially result in vascular disease, such as ? (multiple answers)
pregestational diabetes, hypertension, antiphospholipid antibody syndrome, autoimmune diseases and renal insufficiency, malnutrition, and substance abuse.
Fetal conditions that may result in growth restriction include?
teratogen exposure, including certain medications; intrauterine infection; aneuploidy, most often trisomy 13 and trisomy 18; and some structural malformations, such as abdominal wall defects and congenital heart disease.
Placental pathology resulting in poor WHAT can lead to fetal growth restriction.
placental perfusion
Umbilical cord abnormalities, such as what and what have also been implicated in cases of fetal growth restriction.
velamentous or marginal cord insertion.
In more than HOW MANY of cases of growth restriction, the etiology may be unclear even after a thorough investigation
In more than HALF
Fetal growth restriction is associated with an increased risk for WHAT? (Bold in the PPT)
Stillbirth
The risk for stillbirth is further increased when WHAT occurs in the context of oligohydramnios or abnormal diastolic blood flow in the umbilical artery. (bold in the ppt)
fetal growth restrictions
What two issues further increases risk for stillbirth when fetal growth restrictions are also present? (bold in ppt)
oligohydramnios or abnormal diastolic blood flow in the umbilical artery.
If EFW measures less than the 10th percentile, the risk for stillbirth is what percentage? (the percentage is twice the risk for appropriately grown fetuses)
1.5%
The risk for stillbirth increases to what percentage when the EFW is less than the 5th percentile?
2.5%
What two things can occur which will lead to an improvement in perinatal outcomes? (think in relation to fetal growth restrictions) (bold in ppt)
Early and accurate diagnosis of fetal growth restriction coupled with appropriate intervention leads to an improvement in perinatal outcome.
If fetal growth restriction is suspected clinically and on the basis of ultrasonography, then what should follow in relation to mother and fetus? (bold in ppt)
a thorough evaluation of the mother and fetus is indicated.
True or false
Every effort should be made to identify the cause of the fetal growth restriction and to modify or eliminate contributing factors.
True
Monitoring of a fetus who may have fetal growth restrictions should include what all? (multiple answers) (bold in ppt)
Monitoring should include serial ultrasonographic examinations for growth and amniotic fluid volume, and antenatal surveillance with umbilical artery velocimetry and antepartum testing (nonstress tests or biophysical profiles).
What do you base timing of delivery on? (multiple factors) (bold in ppt)
based on gestational age,
the underlying etiology if known, results of antepartum testing and interval growth scans, and any additional risk factors for an adverse outcome, including maternal co-morbidities.
What is the definition of Fetal macrosomia?
growth beyond an absolute birth weight of 4000 g or 4500 g regardless of gestational age. (bold in ppt)
Tell me the difference between fetal macrosomia and large for gestational age?
Fetal macrosomia, defined as growth beyond an absolute birth weight of 4000 g or 4500 g regardless of gestational age,
should be differentiated from the term large for gestational age (LGA), which implies a birth weight greater than or equal to the 90th percentile for a given gestational age.
what percentage of fetuses born in the US are LGA?
10%
8% of all live-born infants weigh 4000 g or more, and 1.1% weigh more than 4500 g
Vibroacoustic Stimulation- how is this done
Fetal vibroacoustic stimulation (VAS) refers to the response of the FHR to a vibroacoustic stimulus (82 to 95 dB) applied to the maternal abdomen for 1 to 2 seconds in the region of the fetal head (BOLD)
positive result of fetal vibroacoustic stimulation
An FHR acceleration in response to VAS represents a positive result and is suggestive of fetal health. (BOLD)
What injuries are associated with shoulder dystocia?
The fetal injuries associated with shoulder dystocia include fracture of the clavicle and damage to the nerves of the brachial plexus, resulting in Erb-Duchenne paralysis, of which the vast majority resolve by 1 year of age.
An NST alone may not be sufficient to confirm fetal well-being. In such cases, a biophysical profile (BPP) may be performed.
The BPP combines an NST with an ultrasonographic scoring system performed over a 30-minute period
the Biophysical profile is used in what two situations?
what situation is it not used in?
term and preterm fetuses
not during active labor
what are the 5 variables described in the original BPP
The five variables described in the original BPP were
(1) gross fetal body movements,
(2) fetal tone (i.e., flexion and extension of limbs),
(3) amniotic fluid volume,
(4) fetal breathing movements, and
(5) the NST (Table 6.4).75 More recently, the BPP has been interpreted without the NST.
(BOLD)
contraction stress test, also known as the oxytocin challenge test (OCT) how and why is it done
assesses the response of the FHR to uterine contractions induced by either intravenous oxytocin administration or nipple stimulation (which causes release of endogenous oxytocin from the maternal neurohypophysis). (BOLD)
what are the results of a contraction stress test
A minimum of three contractions for at least 40 seconds in a 10-minute period is required to interpret the test. A negative CST (no late or severe late decelerations with contractions) is reassuring and suggestive of a healthy, well-oxygenated fetus
min of 3 ctx for at least 40s in a 10min period is req to interpret the test. a negative CST (no late or severe late decels) is reassuring and suggestive of a healthy well oxygenated fetus.
(BOLD)
Doppler Velocimetry what does it measure? where does it measure it?
Doppler velocimetry can be used for the noninvasive measurement of fetal circulation,
(BOLD)
including the umbilical artery (UA), middle cerebral artery (MCA), and ductus venosus (DV).
which artery is frequently evaluated during pregnancy
the umbilical artery as it is one of the few arteries that normally has diastolic flow.
(BOLD)
Normally, UA resistance to blood flow from the fetus to the placenta falls progressively throughout pregnancy, reflecting an increase in the number of tertiary stem vessels. Factors that affect placental vascular resistance include
gestational age, placental location, pregnancy complications (e.g., placental abruption, preeclampsia), and underlying maternal disease (chronic hypertension).
(BOLD)
doppler velocimetry is used to evaluate
growth restricted fetuses or growth discordance in twin gestations
before in utero surgery can be recommended what must happen
a thorough evaluation must be performed (BOLD)
a thorough evaluation must be performed prior to utero surgery to evaluated
(1) precisely characterize the defect,
(2) exclude associated malformations,
(3) perform a fetal karyotype analysis, and
(4) eliminate the possibility that the condition can be treated using less aggressive technologies. Detailed counseling about the risks and benefits of the proposed procedure is required, and written informed consent is mandatory. Such a discussion must include a detailed review of the risks to both the fetus and the mother, including preterm PROM (28% to 100%), preterm labor and delivery (> 50%), maternal pulmonary edema (20% to 30%), placental abruption (5% to 10%), chorioamnionitis and sepsis (< 5%), and maternal death (rare).
the ideal case for fetal surgery consists of
a singleton pregnancy before fetal viability (before 23-24 weeks gestation)
in which the fetus has a normal karyotype and an isolated malformation that, if untreated, will result in fetal or neonatal demise.
what did the two randomized control trials publish
one on tracheal occlusion for the management of congenital diaphragmatic hernia
the other on rental versus postnatal repair of myelomeningocele
found little benefit to in utero surgery. although pediatric benefit with open maternal fetal surgery for myelomeningocele repair has been observed, there are significant risks including need for C section delivery with all future pregnancies- similar to that for women with a history of a classical c section delivery (BOLD)
when should repair of lesions such as cleft lip and palate be preformed
after delivery to minimize risk to the mother
Intrauterine fetal demise (IUFD)- known as
also known as stillbirth,
-defined as demise of the fetus after 20 weeks’ gestation and before delivery.
still birth rate in US
5.96 per 1000 live births in 2013- half occurring before 28 weeks.
Risk factors for still births include
extremes of maternal age, chromosomal disorders, congenital malformations, antenatal infection, multiple pregnancy, prior unexplained IUFD, postterm pregnancy, fetal macrosomia, MALE FETUS, umbilical cord and placental abnormalities, and
underlying maternal medical conditions (e.g., chronic hypertension, pregestational or gestational diabetes mellitus, autoimmune disorders, inherited or acquired thrombophilia).
(BOLD)
Hydrops Fetalis is?
Hydrops fetalis (“edema of the fetus”) is a rare pathologic condition that complicates approximately 0.05% of all pregnancies.
Hydrops Fetalis US diagnosis requires…
abnormal accumulation of fluid in more than one fetal extravascular compartment, including ascites, pericardial effusion, pleural effusion, subcutaneous edema, and/or placental edema. (BOLD)
overall perinatal mortality rate in the setting of hydros fetalis exceeds what percent
50%
prognosis depends on the underlying cause, severity and gestation age
in 50-75% of hydros fetalis what is seen
polyhydramnios
90% of hydros fetalis cases are a result of
non immune causes such as maternal infection (e.g., with parvovirus B19, cytomegalovirus, syphilis), massive fetal-maternal hemorrhage, and fetal abnormalities (e.g., congenital cardiac defects, fetal thalassemia, twin-to-twin transfusion syndrome).
hydros fetalis can be classically seen in fetuses with severe anemia - resulting form what
Rh isoimmunization, the introduction of Rh0(D) immune globulin has led to a substantial decrease in the incidence of immune hydrops
CHORIONIC VILLUS SAMPLING
Like that of amniocentesis, the goal of CVS is to provide fetal cells for genetic analysis, although in this case the cells are trophectoderm (placental) cells rather than amniocytes.
when is CVS best performed
10 and 12 weeks’ gestation. CVS performed before 10 weeks’ gestation has been associated with limb reduction defects
what is the most common complication of CVS
vaginal spotting, 10-25% of patients within the first few days after the procedure
is pregnancy loss associated with CVS
CVS appears to be associated with a higher risk for pregnancy loss than late amniocentesis
(BOLD)
what is the most serious complication of CVS
spontaneous abortion (BOLD)
one complication unique to CVS involves
interpretation of the genetic test results (BOLD)
AMNIOCENTESIS
Amniotic fluid is composed of fetal urine, lung fluid, skin transudate, and water that is filtered across the amniotic membranes. It contains electrolytes, proteins, and desquamated fetal cells (amniocytes). Sampling of amniotic fluid (amniocentesis) can be used to measure various substances such as lecithin and sphingomyelin for assessing fetal lung maturity, to look for pathogenic bacteria for confirmation of an intra-amniotic infection, and to obtain fetal cells for determination of fetal karyotype or performance of specific genetic analyses.
(BOLD)
amniocentesis
The most common indication for second-trimester
amniocentesis is cytogenetic analysis of fetal cells, although on occasion it is performed to determine amniotic fluid AFP levels and acetylcholinesterase activity for the diagnosis of fetal open neural tube defects. Amniocentesis later in pregnancy is usually performed for nongenetic indications, such as (1) documentation of fetal pulmonary maturity before elective delivery before 39 weeks’ gestation, (2) amnioreduction in pregnancies complicated by severe polyhydramnios, (3) to confirm preterm premature rupture of membranes (PROM) (amniodye test), or (4) to exclude intra-amniotic infection.
(BOLD)
Screening for Fetal Chromosomal Abnormalities
Fetal chromosomal abnormalities are a major cause of perinatal morbidity and mortality, accounting for 50% of first-trimester spontaneous abortions, 6% to 12% of all stillbirths and neonatal deaths, and 10% to 15% of structural anomalies in live-born infants. The most common aneuploidy (presence of an abnormal number of chromosomes instead of usual 46) encountered during pregnancy (autosomal trisomy) results primarily from nondisjunction during meiosis
women greater than 35 years are at higher risk for what
having a pregnancy complicated by fetal aneuploidy and are routinely offered noninvasive prenatal screening and an invasive diagnostic procedure (either amniocentesis or chorionic villus sampling [CVS]). (BOLD)
screening for fetal chromosomal abnormalities continued- random states-
which is the most common disorder
should all women be offered anurploidy?
However, because only 8% to 12% of all births occur in women 35 years of age and older, at most 20% to 25% of all cases of trisomy 21 (Down syndrome) would be identified if all women of advanced maternal age agreed to amniocentesis.101 Klinefelter syndrome (47, XXY) is the most common sex chromosome aneuploidy with a prevalence of 1 : 500 males, and Turner syndrome (45, X) is the only viable monosomy. Many older women are now opting for serum analyte screening for fetal aneuploidy, which is equally accurate in older women. All women, regardless of age, should be offered aneuploidy screening during early gestation.
Perinatal Ultrasonography-uses
high-frequency sound waves that are directed into the body by a transducer, reflected by maternal and fetal tissue, detected receiver, processed and displayed on a screen
Standard evaluation with perinatal US
involves determination of fetal number, presentation, amniotic fluid volume, cardiac activity, placental position, fetal biometry, and an anatomic survey.
Specialized examination-
include fetal Doppler assessments, BPP, fetal echocardiogram and additional biometric measurements, evaluate fetal structures in detail and define characterize fetal malformation.
