Fetus and Newborn Flashcards
What could be a correct explanation for elevated AFP?
Incorrect dates
What are some associations with increased AFP?
RAIN
Renal (nephrosis, renal agenesis, polycystic kidney disease)
Abdominal wall defects
Incorrect dating/Multiple pregnancy
Neurological (anencephaly and spina bifida)
What is low AFP associated with?
Chromosomal abnormalities like trisomy 21 or trisomy 18
AFP is what type of test?
Screening…may need additional studies like US to confirm suspected findings
What does the non stress test measure?
Spontaneous fetal movements and heart rate nativity
Which test measures fetal autonomic nervous system integrity?
Non stress test
What does the contraction stress test measure?
Fetal heart rate in response to uterine contraction
What test measures uteroplacental insufficiency and tolerance of labor?
Contraction stress test
For the CST, is a positive or negative test good, and what constitutes each?
Negative is good…
Negative/Normal means no late or significant decelerations and is reassuring
Positive means late decelerations after 50% of contractions and would require further investigation
What % of fetuses experience arrhythmias?
1%… Most of them are benign
What is the most common cause of fetal bradycardia and what maternal condition is seen with this?
Heart block, may be seen with maternal lupus
When should you treat mom with antiarrhythmic medications and why?
SVT with heart rates exceeding 240bpm…the treatment is to avoid congestive heart failure and hydrops in the fetus
What is the biophysical profile test?
Includes the non stress test, plus an US evaluation of fetal movement, reactive HR, breathing, tone, and volume of amniotic fluid
What is the definition of apnea?
No breath for greater than 20 seconds (less than this would be considered periodic breathing)
Name causes of apnea
- Abnormal metabolism (hypoglycemia, hypocalcemia, anemia, maternal medications)
- PDA and other cardiac causes
- Neurological (seizures, intracranial hemorrhage, apnea of prematurity)
- Epidemiological/Infectious (sepsis, pertussis, RSV, and other respiratory infections)
- Abnormal swallowing/GERD
What is central apnea?
When there is no respiratory effort because there is no signal from the CNS
What is apnea of prematurity?
A subset of central apnea, diagnosis of exclusion
*If there is another cause of apnea, have to provide hint…sepsis, medications, profound anemia, electrolyte abnormality
How do you treat apnea of prematurity?
Caffeine or theophylline
What is the post delivery pattern of primary apnea?
Gasping…with increased depth and rate of respiration…followed by apnea
*At this point, if blow by blow oxygen and stimulation are given, there should be a good response
How can primary apnea be reversed?
Tactile stimulation
If primary apnea doesn’t resolve, what happens and what do you do?
- Another round of gasping, followed by more apnea
- Positive pressure ventilation (oxygen and stimulation won’t work)
Can primary apnea occur in utero?
Yes, so it is difficult to determine if the newborn is experiencing primary or secondary apnea
All apneic newborns who fail to respond to tactile stimulation and remain apneic 30 seconds after delivery require what?
Positive pressure ventilation (under assumption you are dealing with secondary apnea)
What pressure is needed to inflate the lungs with the first breath?
60mmHg
What is transient tachypnea of the newborn?
Tachypnea in otherwise healthy infants
What causes TTN?
Retained fetal fluid
Which babies is TTN more commonly seen in?
Infants delivered by C-section
What does an XR in an infant with TTN show?
Fluid in the interlobar fissures and increased interstitial pulmonary markings
What are signs of TTN and how is it diagnosed?
Presents within first few hours with tachypnea, retractions, nasal flaring, and grunting
Diagnosis of exclusion
What is the respiratory rate in TTN?
Greater than 60
When does TTN resolve?
Within 72 hours
How do you manage TTN?
NPO status and close monitoring
Once symptoms improve, can start feeds. Advance feeds slowly until the respiratory rate falls below 60 breaths per minute
What are the most common causes of coma and lethargy in infants?
Sepsis, metabolic disturbances, asphyxia (distinguish by looking for signs in history)
What has to be included in the history for neonatal hypoxic-ischemic encephalopathy?
Complicated delivery
What are some features of neonatal HIE?
Metabolic disturbances like elevated serum ammonia, lactic acidosis, hypoglycemia, hypocalcemia, and hyponatremia
What is the anion gap in neonatal HIE?
Normal
What is the result of deficient surfactant in the lining of the alveoli?
RDS
When does the surge in surfactant production occur?
Usually after 33-36 weeks gestation
Surfactant levels gradually increase until 33-36 weeks gestation, after this there is a surge
*If an infant is born prior to this, they will be surfactant deficient and suffer from RDS
Why is RDS also known as Hyaline Membrane Disease?
The cellular debris that covers the terminal bronchioles in RDS forms a hyaline membrane
What is the typical presentation of RDS?
Tachypnea, nasal flaring, expiratory grunting, retractions, cyanosis (can be part of picture as well)
What does CXR look like for RDS?
Granular opacifications, air bronchograms, obscure heart/diaphragm borders, ground glass
What is the difference in CXR between RDS and meconium aspiration?
RDS is symmetric findings and meconium aspiration is asymmetrical
What does surfactant do?
Keeps the alveoli open during expiration
If symptoms of RDS persist beyond 3 days, what could be a complicating factor?
PDA
What condition has indistinguishable CXR findings to RDS?
Pneumonia secondary to group B strep
*Have to note something in history like prolonged and progressively worsening symptoms despite respiratory assistance
What coexistent conditions can worsen RDS?
Hypoglycemia (can also mimic RDS), hypocalcemia, anemia, acidosis, extremes of temperature
What can happen if you have hyperbilirubinemia with RDS?
The threshold for kernicterus is lowered
Risk for RDS is increased with what 3 things?
- Infants of diabetic mothers
- C-Section delivery
- Birth asphyxia
Risk for RDS is decreased with what 2 things?
- Prolonged rupture of membranes
2. Prenatally administered steroids
What L:S ratio (lecithin:sphingomyelin) suggests low risk for RDS?
Greater than 2
What can be done before delivery to help decrease the risk for RDS in premature infants?
Prenatal steroids
What maternal condition can interfere with the accuracy of the L:S ratio?
Diabetes
When is mechanical ventilation indicated for infants with RDS (and/or other signs of respiratory failure)?
pH lower than 7.2 and PCO2 greater than 60
What equipment problem is common in infants on a vent?
Air leaks
What else can be used for infants with RDS or respiratory failure besides ventilation?
Exogenous surfactant, high frequency ventilators, ECMO (extracorporeal membrane oxygenation…temporary heart/lung bypass)
What is the goal PO2 with treatment for RDS/respiratory failure?
Maintain PO2 between 50-70mmHG
Once you diagnose RDS, what do you do?
Administer surfactant
If a baby is under 30 weeks or at risk for RDS, do you give surfactant?
Yes, therapy is prophylactic (just after delivery), or early (within two hours of delivery)
If you give surfactant once a diagnosis of RDS is made, what type of treatment is that?
Rescue
What are non-distinguishable things between RDS and GBS pneumonia?
CXR, tachypnea, grunting, respiratory distress
What is one reliable sign of sepsis in the newborn period?
Ratio of bands to total neutrophils
A ratio of bands to total neutrophils greater than what is suggestive of sepsis or pneumonia versus RDS?
0.2 (remember to calculate this ratio when given CBC values)
What is an exam finding in history that is a good clue to consider pneumonia over RDS?
Temperature instability
After giving surfactant, clinical improvement is expected in what 3 forms?
- Decreased oxygen requirement
- Reduced inspiratory pressure
- Improved lung compliance
What changes to pulmonary compliance and inspiratory pressure happen with expected improvement with surfactant?
Increased pulmonary compliance and decreased inspiratory pressure go with improvement
(Decreased pulmonary compliance and increased inspiratory pressure are not expected improvements with surfactant)
What can account for some deterioration in infants with RDS on ventilators and is air leaking into the interstitium (often precedes a full-blown pneumothorax)
Pulmonary interstitial emphysema (PIE)
What is bronchopulmonary dysplasia?
A chronic lung disease
Used to think it was due to prolonged mechanical ventilation and oxygen exposure
Now believed to be due to arrest of normal lung development in premature infants (with therapeutic advances)
What is chronic lung disease definition for infants?
CLD is present in infants who still have an oxygen requirement 28 days after birth and/or continued oxygen requirement at 36 weeks corrected gestation
How is BPD treated and what is a possible side effect of treatment?
Diuretics…risk for hypocalcemia
What type of twins are at a higher risk for complications and why?
Monozygotic twins…because they share a chorion and an amnion
Which twin is at higher risk for developing respiratory problems?
B twins at higher risk than A twins
When/who is ECMO used for?
Primarily for infants with reversible lung disease of less than 10-14 days duration, with failure of other methods
What 2 things must an infant NOT have to be eligible for ECMO?
No systemic or intracranial bleeding or congenital heart disease
What is the typical CXR description for an infant with BPD?
Diffuse opacities, cystic areas with streaky infiltrates, ground glass appearance
What are 2 things to consider in a lethargic and floppy baby with weird labs besides sepsis?
Congenital adrenal hyperplasia and inborn errors of metabolism
What is the empirical treatment of suspected neonatal sepsis?
Ampicillin and gentamicin (don’t choose cefotaxime…it is responsible for outbreaks of drug resistant enterobacter and serratia)
Infant with classic signs of sepsis, labor and delivery unremarkable, mom had slight fever and flulike symptoms, placental had white nodules…bug and drug?
Listeria, ampicillin and gentamicin
How can group B strep present?
Anything from asymptomatic bacteremia to septic shock
What is group B strep?
Strep agalactiae
What are the initial clinical findings in 80% of newborns regardless of the site of infection with group B strep?
Respiratory symptoms, tachypnea, grunting, flaring, apnea, cyanosis
When does GBS early onset infection present?
First 7 days after birth
When does GBS late onset disease present?
Generally in first month of life, may present up to 90 days after birth
Is late onset GBS usually associated with obstetric or birth complications?
No
Who does late-late onset GBS disease present in and when?
Preterm infants, may appear at up to 6 months
She do you screen mom for GBS?
35-37 weeks gestation
What is done for mom who is GBS positive, or wasn’t tested but has sepsis risk factors?
Intrapartum antibiotic prophylaxis unless c-section is done before onset of labor or rupture of membranes
What do you do for infants of mothers with suspected chorioamnionitis?
Get a CBC and blood cultures and start antibiotics pending culture results
What to do for well appearing infant with mom who had inadequate treatment of GBS?
Monitor for 48 hours prior to discharge
What is the drug of choice for treatment of proven GBS?
Penicillin…no known resistance
What are risk factors for early onset disease with GBS?
- Maternal colonization at birth
- Preterm birth under 37 weeks
- ROM over 18 hours before delivery
- Chorioamnionitis
- Multiple gestation
- Nonwhite maternal race
- Intrapartum fever over 38
- Intrauterine monitoring
- Postpartum maternal bacteremia
- Previous infant with invasive GBS disease
If mom is described as asymptomatic during pregnancy what is the likely bug for newborn sepsis?
GBS
If mom was described as having flu like illness during pregnancy, what is the likely bug causing newborn sepsis?
Listeria
What is usually necessary for a birth trauma clavicular fracture?
Watchful observation
When can you expect the clavicular fracture callus to recede from birth trauma?
Within 2 years
If you get a neonatal CXR, what should you make sure not to miss?
Clavicular fracture (easy to focus on lungs and GI and miss this)
What 2 nerve issues can result from a clavicular fracture?
Erb’s palsy and phrenic nerve palsy
What % of deliveries do brachial plexus injuries occur in?
Half a percent
Where does Erb’s palsy occur?
C5-C7
How does Erb’s palsy present?
Classic waiter’s tip…adducted, internally rotated, wrist and fingers flexed, limited shoulder movement
What birth problem is Erb’s palsy associated with?
Clavicular fractures
What to think of in infant with Erb’s palsy and respiratory distress?
Phrenic nerve paralysis (leads to respiratory distress…clavicular fractures can cause both)
Where does Klumpke palsy occur?
C8-T1
How does Klumpke palsy present?
Claw hand…affects muscles in hand
Someone being born grabbing a Klump of sand
What can happen to hand mobility in Klumpke palsy?
They can lose ability to grasp, despite initial presentation of claw hand
What eye issue can Klumpke palsy be associated with?
Horner syndrome
Which is more common, Erb’s or Klumpke palsy?
Erb’s palsy
What happens to grasp with Erb’s palsy?
Ability to grasp is preserved, so grasp reflex remains intact (with Erb’s palsy, the nerve is stretched, not broken)
When should the umbilical cord fall off?
By the 2-week visit
What should you be concerned for if the umbilical cord stays attached beyond one month?
Leukocyte adhesion deficiency or low WBC count
What do you do for care for the umbilical stump?
Wash with soap and water and pat dry (no decreased infection risk by applying alcohol to stump)
Are cultural remedies okay for umbilical stump?
They are okay, as long as they don’t do any harm (like applying mercurochrome…which contains mercury…this isn’t available in U.S., but could be on boards)
What do you do for a newborn with a single umbilical artery?
Renal ultrasound
*In real world, most instances of a single umbilical artery aren’t associated with renal disease
Where should the baby be before clamping the cord?
The baby should be kept below the cord for around 30 seconds to prevent decreased red cell volume
What could the obstetrician milking the cord towards the baby cause?
Polycythemia…obstetrician should not milk the cord towards the baby
Is breast hypertrophy in a newborn a benign finding?
Yes…even if milk is produced (witch’s milk)
What do you do for an infant with breast hypertrophy and milk production?
Leave it alone…don’t express milk by squeezing it out. This makes it worse because it stimulates prolactin and oxytocin secretion and prolongs it. Also increases risk for mastitis.
What is an SGA baby?
In lower 10th percentile for weight for gestational age
What is an LGA baby?
Above the 90th percentile for weight for gestational age
LGA is greater than how many grams?
3900g
SGA is less than how many grams?
2500g
Which babies have a higher morbidity and mortality risk than AGA babies?
SGA
In short term, SGA babies are at higher risk for what?
Temperature instability, polycythemia, and fasting hypoglycemia
SGA stands for…
Small for gestational age
SGA infants are born with what?
Intrauterine growth retardation
Are all preemies SGA?
No, preemies won’t be SGA if their weight is appropriate for their gestational age
Why is IUGR often associated with perinatal asphyxia?
Because IUGR babies tend to have more difficulty tolerating labor
Infants of mothers with chronic illness are at higher risk for being what?
SGA
Teenage mothers are at higher risk for delivering what type of babies?
SGA
When do SGA babies catch up on growth?
May catch up once removed from the restrictive uterine environment
If the growth failure is due to an inherent infant condition (congenital infection), growth will likely not catch up
What is the definition of full term?
40 weeks plus or minus 2 weeks…any baby born in range of 38-42 weeks is considered full term (42 week baby is considered term)
What is considered post term?
More than 2 weeks post dates
Dry skin that is peeling, long fingernails, decreased lanugo on the back, ears with strong recoil
Post term newborns
What are the most common causes of fetal demise?
Chromosomal abnormalities, congenital malformations
What is normal arterial pO2 and pCO2 for a newborn infant?
PO2: 60-90mmHg
PCO2: 35-45mmHg
Scalp pH of 7.29, what do you do next?
Nothing but reassure
Normal scalp pH is 7.25 or higher (they can present you with normal pH and imply in question that it is abnormal)