PPt. 1-3 Flashcards
Generally takes __ days for conceptus to migrate from fallopian tube into uterus
8
when is the fertilized egg independent of environment but not of genetics
pre-embyronic phase
8 days from fertilization to implant
when is the embryonic phase
weeks 3-8
the time when all of the tissues are specializing and organs are forming
Period of Organogenesis
when is the Period of Organogenesis
embryonic phase
weeks 3-8
-Time when malformations occur and greatest vulnerability to teratogens
Period of Organogenesis during the embryonic phase (weeks 3-8)
Embryonic development into what 3 germ layers
- Ectoderm will become skin and nervous system
- Mesoderm will become muscle and bone
- Endoderrm will become GI tract (alimentary canal), endocrine and respiratory systems
When can you start to see the heart beat
on 6 week ultrasound
When is the fetal phase
9 weeks until delivery
What happens during the fetal phase
Further growth, differentiation and maturation of organs
when do Pulmonary alveoli begin to develop
24 weeks
When does surfactant present in lungs
at 34 weeks
What is the importance of surfactant
it reduces the surface tension of lungs to keep the alveoli open so baby can breath
What happens if the baby is born before 24 weeks
pulmonary alveoli won’t be develooped and the fetus won’t be viable outside the womb
Fetal membranes and what do they do
Amnion is inner layer
Chorion is outer layer
Function: act to protect fetus from injury and infection
What happens when a mother’s water breaks
the fused chorion/aminion membrane ruptures and amniotic fluid poors out
PROM
prolonged rupture of membranes > 18 hr
*prior to delivery- makes you prone for infection
PPROM
premature, prolonged ROM
*breaks prior to 35 weeks of gestation
SROM
spontenous ROM
AROM
artificial ROM
*can have AROM that becomes PROM
What are the functions of amniotic fluid
- Acts as a cushion for fetus as mother moves
- Prevents membranes from sticking to baby
- Allows for fetal movement
- Necessary for lung development
How does the fetus contribute to the placenta
Chorionic villi
Finger-like projections of chorion which penetrate into the endometrium, the lining of the uterus
Chorionic villi
what does a chorionic villi contain
- fetal arteriole, venule, and capillary
What is the placenta made up of
- Chorionic villi- fetal contribution
2. Decidua Basalis- maternal contribution
What happens when c.villus invades the endometrium
it causes the maternal capillary beds to break down into sinusoids
blood flow in placenta
arteriole –> open space –> venule
Where is the fetal capillary
sits within the sinusoid and is bathed by maternal blood
*drug transfer occurs this way
Mother to fetus exchange across the placenta
oxygen, aminio acids, fats, glucose, some hormones, antibodies, most drugs, viruses
Fetus to mother exchange across the fetus
carbon dioxide, bilirubin, ammonia and other waste products
“crossing the placenta” refers to
the diffusion of molecules in either direction
What happens if mom has DM1 and has high blood sugars high throughout the pregnancy. Therefore baby see lots of maternal glucose in utero but what happens with insulin?
- insulin does not cross placenta because too big of a molecule, therefore baby’s pancreas produces its own insulin to take care of mother’s glucose
- baby continues to produce insulin after birth and becomes hypoglycemic–> may require force feeding
What produces hCG
the chorion (or more generally the placenta)
What hormones maintain the lush endometrium necessary to sustain pregnancy
hCG and progesterone
When is there enough hormones for a pregnancy test to detect pregnancy
2 weeks post conception
maternal blood and urine
What hormone does a pregnancy test detect
hCG
when does ovulation occur
14 days before menstruation (regardless of cycle length)
How do you date pregnancy?
date pregnancy counting 40 weeks from first day of last menstrual period
When does pregnancy actually start occuring, when dating pregnancy
2 weeks before ovulation and fertilization
Whats the purpose of ultrasounds
- Dating pregnancy
- Evaluating anatomy
- Checking position of placenta (important for C-sectino and wanting a chorionic villi sample)
- Checking volume of amniotic fluid
Useful early on in pregnancy because can get closer to fetus and give more accurate images in first weeks
transvaginal u/s
Disadvantage of transvaginal u/s
uncomfortable for mother (its tucked under the cervix)
More standard u/s
transabdominal u/s
what do you measure with U/S dating in 1st trimester and what is its accuracy
Measure crown-rump length
Accurate +/- 3 days
what do you measure with U/S dating in 2nd trimester and what is its accuracy
Measure biparietal diameter
Accurate +/- 1 week
what do you measure with U/S dating in 3rd trimester and what is its accuracy
measure biparietal diameter
Accurate +/- 2 weeks
Why is it important to accurately date your pregnancy
- Surfactant develops around 35 weeks
- know the development of other systems
Why is dating less accurate later on in the pregnancy?
genetics, environmental factors, difficult to visualize teh baby due to its position and limbs
What is considered the 1st trimester
weeks 1- 12
What is considered the 2nd trimester
weeks 13- 28
What is considered the 3rd trimester
weeks 29- delivery
what is considered the ideal term?
40 weeks, or 38-42 weeks
no later than 42 weeks bc placenta starts to die off and baby gets too big
Can maternal antibodies cross the placenta
yes
Rh incompatibilty
mismatch between maternal and fetal blood types that results in mother making anitbodies to fetus blood cells and results in hemolysis of fetus RBC
What can Rh incompatibilty cause
jaundice hydrops fetalis (total body edema)
Prenatal screening consists of:
- Rh compatibility
- u/s for anatomy
- Glucose tolerance test (16 weeks)
- option gentic screening
- Hep B*
- HIV*
- Syphilis, Gonorrhea, Chlamydia*
* at first prenatal visit - Immunity to Rubella (conferred by vaccine)
- GBS at 36- 37 weeks
- Alpha fetoprotein
- other disease specific to population
when is the best time to do an u/s for anatomic survey
18-20 weeks when all the organs have formed
later than that then baby is too large to see details bc of superimpsed body parts
what type of u/s do you do for an anatomic survey
transabdominal
Optional screening offered to patients deemed to be at increased risk of having baby with genetic problems:
- Advanced maternal age (35 or older)
- Abnormal findings on prenatal ultrasound
- Family history of genetic disorder
- Previous miscarriages
what are the 2 forms of genetic testing
- amniocentesis (go through abdomin)
2. chorionic villus sampling (go through abdomin or up vaginal canal)
pros and cons of amniocentesis
P: can do whenever during pregancny
C: 1. mom can have cramping
2. can introduce bacteria to baby
3. can nick the baby or the cord
pros and cons of chorionic villus sampling
P: less risk
C: can only perform in a certain time frame (11-14 weeks)
Fasting blood sugar provides a baseline for comparing other glucose values
glucose tolerance test, testing for maternal diabetes
Pregnant women drink ___ grams of glucose.
Blood samples will be collected at timed intervals of __ and ___ hours after patient drinks the glucose.
drink 75grams of glucose
collect at intervals of 1 and 3 hrs
when is the glucose tolerance test performed
16 weeks
when do you screen for GBS
36- 37 weeks
What does alpha fetoprotien screen for
- high in neural tube defects
- low in down syndrome
“Ashchkinasi screen”
for diseases found in people of European Jewish descent
The process by which products of conception (baby, placenta, cord and membranes) are expelled from the uterus
labor
Requires progressive effacement (thinning) and dilation of the cervix, resulting from rhythmic contractions of the uterine muscles
labor
Dilatation in absence of contractions
cervical insufficiency
ways to decrase cesarean deliveries
- allow prolonged latent (early phase labor
- changing the definition of active labor to start at 6 cm (instead of 4cm)
- Allowing more time for labor to progress in the active phase
- Allowing women to push for at least two hours if they have delivered before, three hours if it’s their first delivery, and even longer in some situations, for example, with an epidural.
- Using techniques to assist with vaginal delivery, which is the preferred method when possible. This may include the use of forceps, for example
- Encouraging patients to avoid excessive weight gain during pregnancy.
Process whereby baby’s heart rate and its response to uterine contractions is monitored
fetal monitoring
what is a normal fetal heart rate
120-160 bpm and should show variability
Fetal heart rate usually _____ with contractions
increases
_______ after contraction or _________ are abnormal
decelerations
slow recovery to baseline
Decelerations after contraction can indicate
- stress
2. need for operative intervention
This type of monitoring uses a doppler to pick up the babies heart rate and tocodynamometer to measure the intensity of contractions
external monitor
cons on external fetal monitoring
sussceptible to artifact and requires that mom and baby remain relatively still
An electrode screwed to the babys scalp can accurately measure fetal heart rate including subtle variations
internal fetal monitoring
Cons of internal fetal monitoring
requires rupture of membranes leaving potential site of infection
Late decelerations are associated with
uteroplacental insufficiency or decreased uterine blood flow
The pain of labor and delivery is a result of
muscular contractions and pelvic pressure from organ distention
In what stage of labor does autonomic innervation of the visceral uterus senses pain from contractions and cervical dilation.
1st stage
In what stage of labor does somatic innervation of the vagina, vulva, and perineum sense pressure pain from the newborn passing through the birth canal
2nd stage
do narcotics cross the placenta
Yes, but only some cross the fetal blood-brain barrier
Fentanyl (an opiate) used for pain managment in pregnancy
- drug of choice bc of short half-life
- risks include include hypotension, nausea, vomiting, respiratory depression, depressed mental status, and decreased GI motility
- make sure resuscitation medication and equipment for the newborn should be readily available
Epidurals provide ___ not _____
provide analgesia NOT anethesia
risks of epidurals
- short-term backache
- puncture headache,
- hypotension,
- maternal fever,
- prolonged labor, and
- increased rate of instrumental delivery
Do epidurals increase a mother’s risk of delivering by cesarean?
no
when can you do an epidural?
any time
placement of epidural at maternal request regardless of cervical dilatation
amniorrhexis
rupture of membranes
birth starts with
amniorrhexis
Membrane ruptures when in relation to labor
before or during labor
Not related to specific stage
What is the purpose of amniotic sac
cushions the fetus
guards it from infection
- Facilitates monitoring
- Increases force of contractions
- Risk of cord prolapse if head is not “engaged”
AROM
- Defined as rupture greater than 18 hours
- Increases the risk of ascending infection
PROM
Rupture prior to 37 weeks
PPROM
Baby delivered with membranes intact is said to be
delivered “en caul”
(Irish legend has it that the baby will be protected from drowning and It’s considered lucky and some believe increases psychic ability)
forms of operative deliveries
- forceps
- vacuum
- cesarean section
risks of using forceps
- skull fractures
- facial nerve palsy
(affected side will not have creases and eye may remain open–> consider using artifical tears)
risks of using a vaccum
- shearing forces on the scalp can cause subgaleal hemorrhage
- cephalohematoma
- damage to skin.
risks of c-sections
- retained lung fluid
- lacteration of the fetus
- surgical complicaitons
- prolonged recovery for mom
The most common presenting birth position
occiput anterior (OA): head first, face down
occiput posterior (OA)
head first, face up
transverse lie
baby is positioned horizontally, incompatible with vaginal delivery
Breeching position
when the buttocks are delivered before the head
Recommendations of breeched babyies
- attempt external cephalic version (an attempt to turn the baby by manipulated the fetus from the outside of the maternal abdomen)
- depends of physicians preferance/ experience
when doe the transitional period for a newbord occur
first few hours after birth
periodic breathing
bursts of rapid breaths, slowing, then rests for
what is the cause of a newborns periodic breathing
immature CNS
*Not respiratory in origin
normal axillary temperature for a new born in transition
36.5-37.5°C
normal heart rate for a new born in transition
80-160 beats/min
normal respirtory rate for a new born in transition
30-60 breaths/min
normal BP for a newborn in transition
60/40
Skin to Skin Care is associated with
- increased body temp (compared to those who used warmers)
- longer duration of breast feeding
- longer sleep periods
- better organization
If baby is at ambient warmer, turn heat to ___ and then do what
100%
- dry quickly to avoid evaporative loss
- dress with a hat ASAP
When should you bathe a newborn
- after their temperature is stable and infant is acting well
- adequate skin to skin and bonding with mom (6 hrs)
Risks of hypothermia
- Breakdown of proteins and fats as fuel to create heat
- fatigue
- weight loss
goal of temperature management of a newborn
prevent heat loss
3 preventative interventions given within 2 hrs of delivery
- Eye prophylaxis with 0.5% erythromycin ophthalmic ointment
- HepB vaccine
- Vitamin K, 1mg IM
why is 0.5% Eyrthromycin opthamlmic ointment is placed in both eyes
preventing gonorrhea and chlamydia infections of the eye
Why is HepB given at birth
risk of chronic disease with congenital infection is high
Approximately ____ of infants infected by HepB are infected from their mothers at birth, and between __ and __% of those infected before age ____, become chronic HBV carriers
90%
30-50%
5
Why is Vit. K given at birth
Prophylaxis against early and late Vitamin K Deficiency Bleeding (Endogenous Vitamin K levels low until eighth day of life)
how is Vit. K administered orally
generally 2-3 doses but less studied in US
how does vit. K prophylaxis prevent VKDB
Promotes hepatic synthesis of vitamin K-dependent clotting factors
facial nerve damage from forceps usually resolves when
within first 48 hrs
- completely by 2 months
- *there is risk though of long term paralysis
collection of blood that does not cross suture lines and is taught (not fluidy), often occurs with caput
cephalhematoma
large potential space where baby can bleed out.
subgaleal hemorrhage
How do you treat GBS + moms
use penicillin (5 million units) 4.5 hrs prior to delivery and second bag (2.5 million units) just prior to delivery
Normal respiration duirng transition
RR= 40-60
periodic breathing
pO2>85%
a baby can be apnea for how long before it is considered abnormal
10 seconds
tachypnea and retractions reflect what
increased work of breathing “WOB”
what is considered tachypnea
RR >60 breaths/min
Tachypnea is the most sensitive indicator of
Lower airway disease
what an infant is found to be in any sort of respiratory distress, what is your first course of action
complete a cardiac and respiratory exam
grunting or singing on exam reflects what
baby’s attempt to keep air in lungs to prevent collapse
grunting or singing are on inspiration or expiration?
expiration
is stridor inspiratory or expiratory?
inspiratory
what does stridor indicate
obstruction of middle airway
crackles or rales indicate
fluid in the air-spaces
are crackles and rales inspiratory or expiratory
inspiratory
are wheezing or rhonchi inspiratory or expiratory
expiration (inspiration when severe)
wheezing or rhonchi indicate
air trying to escape past obstruction in middle airways
auscultory noises
- crackles or rales
2. wheezing or rhonic
audible noises
- grunting or singing
2. stridor
what is the primary muscle of breathing
diaphragm
look for “pulling” of these areas to look for respiratory distress
- suprasternal
- intercostal
- paradoxical movement of abdomen
pallor indicates
early sign of hypoxia
blue color of skin and muccous membranes, occurs O2 sat.
central cyanosis
acral cyanosis reflects ___ rather than ____
reflects perfusion
rather than oxygenation
is perioral cyanosis worrisome
usually not–> sign of acral cyanosis
-check mucous membrane color
simple non-invasive technique to measure oxygen saturation of blood
Pulse oximetry
90 on pulse ox means
90% of RBCs are carrying O2
how does pulse work
by measuring the amount of light in an appropriate spectrum
acceptable O2 sats at birth 2 min- 3 min- 4 min- 5 min- 10 min-
2 min- 60% 3 min- 70% 4 min- 80% 5 min- 85% 10 min-90%
can tolerate O2 sats of ___-___% for the first few hours of life, if baby is otherwise asymtomatic
85-87%
why might the % sats be different depending upon which hand you place the probe?
Left will be higher when the DA is still open (postductal)
what hand is the preferred hand to take the SpO2 of a newborn
right hand (preductal) -more representative for brain oxygenation)
Causes of increased WOB
- pulmonary disorder (upper airway obstruction, lower airway)
- cardiac disorders
- Infection
- Hematological disorders
- Metabolic disorders
what is the most common cause of respiratory distress in newborns
Pulmonary disorder
-Lower airway is more common than upper airway
causes of lower airway diseases
- aspiration, including mesconium
- Hyaline membrane disease/RDS
- pneumothorax
- TTN (transient tachypnea of newborn)
- pneumonia
causes of upper airway obstruction
- nasal stuffiness
- choanal atresia
- masses
- micrognathia (gnath=jaw)
- laryngeal or tracheal obstruction (middle airway)
complications associated nasal obstruction
- noisy breathing
- increased WOB
- feeding can be a challenge
how to examine for nasal obstruction
- check nasal patency
2. try passing a small soft feeding tube through each nostril
what is the most common cause nasal stuffiness
vernix, mucus or old blood blocking the airway
causes of nasal stuffiness
- vernix
- mucus or blood blocking airway
- swelling of mucosal lining from enthusiastic suctioning (especially with DeLee catheter)
- Dry air (colorado)
when the thin tissue separating the nose and mouth area during fetal development remains after birth
choanal atresia
cause of choanal atresia
unknown
Presents with a baby who is cyanotic at rest and pink with crying
choanal atresia
how to treat choanal atresia
surgical intervention
the middle airway is comprised of
larynx and trachea
Causes of middle airway obstruction
- blockage within: voal cord paralysis
- compression from without: tumor
- floppy airway
what is the most common middle airway obstruction
floppy airway
how does floppy airway present
presents with stridor with each breath and deep retractions
-better when baby is placed on stomach (gravity opens airway)
RFLL stands for
Respiratory fliud liquid in lungs
RLL is the same as ___
TTN
transient tachypnea of newborn
why are fetal lungs filled with fluid
- acts as a barrier to the passage of O2 from alveolous to bloodstream
- lungs are stiffer when filled (increase pulmonary pressure)
How do fetal lungs clear fluid
- hormonal changes associated with labor and 2-3 days prior to labor (40% fluid is cleared before NSVD)
- neg. pressure in lungs with first breaths
Why do c-section babys have risk of RFLLS
don’t experince the hormonal changes associated with labor that help clear fluid
if you suspect Lower airway disease what test would be useful
chest xray
how to read a chest xray
R-rotation (compare clavicles)
I-inspiration (count at least 9 ribs)
P-penetration (check intervertebral discs)
A-airway (trachea should be midline and see bronchi splitting)
B-bones (look for fractures/abnormalities)
C-cardiac silhouette (
if blunted costophrenic angles on chest xray, think ___
pulmonary effusion
pulmonary vasculature should fill ____ if it extends beyond this think ______
medial 1/3
if extends think heart failure
when does RFLL resolve
symptoms resolve 1-5 days w/ minimal intervention
tachypnea and hypoxia which resolve in 1-5 days
RFLL or TNN
diagnosis is exclusion
RFLL or TNN
CXR shows: ill-defined peri-hilar fluid*, hyperinflation, pleural effusions
RFLL
“well silhouette” on CXR
RFLL
causes of aspiration
- meconium
- amniotic fluid
- maternal blood
how often is meconium present in amniotic fluid duirng deleiveries
12%
what percent of deliverys are complicated by meconium aspiration
4-6%
how the percentage of deliveries complicated by meconium aspiration, how many require mechanical ventilation
50%
meconium aspiration is most common is who
term or near term infants
passage of meconium is rare before ___
34 weeks
why does MAS occur
- if fetus is stressed in utero and gasps in meconium from amniotic fluid
- thick, viscous meconium in the oropharynx at birth can contribute to postnatal aspiration
3 serious outcomes of MAS
- persistent pulmonary hypertension of newborn (PPHN)
- blockage of small airways, over inflation and pneumothorax
- Pneumonia (inflammatory rather than infection)
cause of PPHN
MAS
how does meconium cause PPHN
- Mec can inactivate surfactant
- cause inflammation and a thick coating obstructing the airway
- results in increased PVR
what occurs when pulmonary vascular resistance remains elevated, resulting in right to left shunting of blood through fetal circulatory pathways
PPH
Echo results: normal structural anatomy with flattened ventricular septum, right to left shunting through thte DA and/or FO
PPHN
Gold standard diagnostic test for PPHN
echo
treatment of PPHN
- supplemental oxygen
- surfactant infusion
- inhaled nictric oxide
- ventilation support
Hyaline membrane disease/RDS occurs almost exclusively in
premature infants
RDS is a result of
surfactant deficiency
RDS can be seen in near term babys (34-37 weeks) if:
- mother is diabetic (hyperglycemia/hyperinsulinemia can delay lung maturation and surfactant production)
- Septic infant (inflammatory response causes “washout”)
RDS is indishinguishable from ___
pneumonia
*therefore history is critical
CXR: ground glass appearance or white out of lungs
RDS
caused by microatelectasis of alveoli
RDS
how is RDS treated
recombinant surfactant and ventilator support
air leak outside of lung, within chest wall
pneumothorax
progressive accumulation of air leakage outside of lung leads to
collapse of lung
risk factors for what disease include:
- positive pressure ventilation
- stiff lungs
- aspiration
pneumothorax
when does pneumothorax typically occur
at delivery (bc the first breath a baby takes is enormous)
___% of all newborns have pneumothorax
1%
T/F: all pneumothorax are symptomatic
F: some small pneumothoraces may be asymptomatic
these signs indicate what disease:
- sudden cyanosis
- respiratory distress
- asymmetric breath sounds
- muffled heart tones
- poor perfusion/mottling/pallor
pneumothorax
CXR: dark film on edges of lungs
pneumothorax
what do these pathogens typically cause: GBS E. coli other gram neg. rods Staph species Listeria
pneumonia
what do these pathogens cause less commonly: ureaplasma chlamydia herpes simplex CMV
pneumonia
pneumonia caused transplacental
bactermia
pneumonia caused ascending
chorioamnionitis, PROM + GBS
inflammatory exudates in the lungs interfere with surfactant function in what disease
pneumonia
pleural effusin are common and PPHN can develop with
pneumonia
CXR: fluffiness
pleural effusion/ pnuemonia
