Fetal Assessment L3 Flashcards
risk factors/indications for fetal assessment
1) biophysical
2) psychosocial
3) sociodemographic
biophysical risk factors indicating need for fetal assessment
Genetic
* gene mutations
* inherited disorders
* ABO incompatibility
* multiple gestation
* large fetal size
Nutritional status
* folic acid and/or iron deficiency
* closely spaced pregnancies
* anemia
Medical and obstetric disorders
* chronic HTN
* IDDM
* type 2 DM
* HIV
psychosocial risk factors indicating need for fetal assessment
1) smoking - constricts vessels and leads to low birth weight baby
2) caffeine - > 200mg/day (12oz coffee) leads to IUGR
3) alcohol - any amount can lead to FASD
4) drugs - teratogenic, CNS depression, NAS
5) psychological status - medications, IPV, situational crises
IUGR
intrauterine growth restriction
FASD
fetal alcohol spectrum disorder
IPV
intimate partner violence
IDDM
insulin dependent diabetes mellitus
what hematocrit value indicates anemia?
HCT < 33%
recommended folic acid supplementation for a woman of childbearing age:
400mcg daily
recommended folic acid supplementation for a woman in the first three months of pregnancy who has Hx of baby with NTD:
4mg
food sources of folate/folic acid:
1) liver (chicken, goose, turkey, beef, etc)
2) legumes
3) beans
4) leafy greens
what legumes are a good source of folic acid?
black eyed peas, garbanzo beans, lentils
what beans are a good source of folic acid?
black and pinto
what leafy greens are a good source of folic acid?
spinach, collards, broccoli
iron is better absorbed with which vitamin?
vitamin C
what are the sociodemographic risk factors that indicate a need for fetal assessment?
1) low income
2) lack of prenatal care
3) age (adolescents or mature parents)
4) parity
5) marital status
6) residence
7) ethnicity
8) environmental factors
9) SDOH
what conditions are pregnant adolescents at higher risk of?
1) anemia
2) preeclampsia
3) prolonged labor
4) contracted pelvis and cephalopelvic disproportion
what conditions are mature pregnant women at risk for?
1) chronic HTN & preeclampsia
2) diabetes
3) prolonged labor
4) cesarean birth
5) placenta previa
6) placental abruption
7) death
what conditions is the fetus of a mature pregnant woman at higher risk for?
1) low birth weight and macrosomia
2) chromosomal abnormalities
3) congenital malformations
4) neonatal death
what are women pregnant for the first time at higher risk for?
1) preeclampsia
2) dystocia
dystocia
long or difficult labor that results in a lack of progress during labor
what are unmarried pregnant women at higher risk of?
increased mortality and morbidity
* higher risk for preeclampsia due to inadequate prenatal care
SDOH
social determinants of health - availability and quality of healthcare
PUBS
percutaneous umbilical cord sampling (infrequently used)
AFP
alpha fetoprotein
screening vs. diagnostic tests
- screening - to discover an increased risk for a fetus having a condition
- diagnostic - determine that a fetus has a condition (with as much certainty as possible)
ex. of screening and diagnostic tests
- screening for trisomy 21 - nuchal translucency ultrasound at 15 weeks
- diagnostic for trisomy 21 - amniocentesis positive for trisomy 21
examples of biophysical assessments
1) daily kick count (begin at 26-28 weeks)
2) ultrasound
3) MRI
kick count goal:
10 movements within 2 hours
fetal alarm signal
the absence of fetal movements for 12 hours
when is ultrasound used on pregnant women?
throughout pregnancy (all three trimesters)
during the second and third trimesters, ultrasound is used to assess:
1) fetal viability, number, position, age, growth patterns, and anomalies
2) placental location and condition
3) presence of uterine fibroids or anomalies
4) presence of adnexal masses
5) cervical length
AFV
amniotic fluid volume
AFI
amniotic fluid index - depth of amniotic fluid in all 4 quadrants
DVP
deepest vertical pocket
Specs for AFI findings:
- < 5cm = oligohydamnios (amniotic fluid deficiency)
- 5 - 24cm = normal
- > 25cm = polyhydramnios (excessive amniotic fluid)
Specs for DVP findings:
- < 2cm = oligohydramnios
- 2 - 8cm = normal
- > 8cm = polyhydramnios
MRI for fetal assessment
- used to assess soft tissues (fetal or maternal)
- can diagnose placental issues
not used often
amniocentesis
collection of fetal cells via insertion of a needle into the uterus
*done after week 14 when the uterus is in the abdomen
what does an amniocentesis detect?
1) diagnosis of congenital abnormalities and genetic disorders
2) assessment of lung maturity
3) karyotype
4) fetal hemolytic disease
what does increased AFP levels detected in an amniocentesis indicate?
possible neural tube defect
what are the risks of amniocentesis?
risk level <1%
1) miscarriage
2) bleeding (Rh neg rhogam)
3) infection
4) injury to fetus/fetal death
when its PUBS most commonly used?
during IUT (intrauterine transfusion) during the 2nd and 3rd trimesters
examples of biochemical fetal assessments:
1) amniocentesis
2) chorionic villus sampling (CVS)
3) PUBS
4) maternal tests
what is assessed during an amniocentesis to determine lung maturity?
lecithin/sphingomyelin (L/S) ratio or the presence of PG or LBC
what maternal tests are performed for fetal assessment?
1) alpha fetoprotein (AFP) - detects neural tube defects (spina bifida, myelomeningocele, anencephaly)
2) genetic screening - detects fetal chromosomal abnormalities
3) Coombs - checks for Rh incompatibility
4) cell-free DNA - detects chromosomal abnormalities and sex
when is chorionic villus sampling done?
10-12 weeks
difference between amniocentesis and chorionic villus sampling:
amniocentesis - u/s is used with a needle that is inserted into the uterus through the abdomen
chorionic villus sampling - u/s used also but sample is collected via catheter that is inserted through the vagina and cervix
FHR
fetal heart rate
abnormal FHR patterns are associated with:
fetal hypoxemia
if uncorrected, fetal hypoxemia can…
lead to fetal hypoxia that can cause metabolic acidosis
what are ways to detect FHR?
1) doppler
2) ultrasound transducer
3) internal fetal monitor (IFM or FSE) - ROM has to have occurred to do this
what are ways to detect uterine contractions?
1) tocotransducer/tocodynamometer (toco)
2) intrauterine pressure catheter (IUPC) - used when ROM occurs
what do the vertical lines on EFM monitors mean?
thick red lines indicate 1 minute
small boxes are 10 seconds across and 10 bpm up and down
on an EFM monitor, what is displayed on the top section and what is displayed on the bottom section?
top - FHR
bottom - uterine contractions
how do you calculate the curation of uterine contractions?
from onset to onset
what is baseline FHR on EFM?
baseline - average over a 10 minute period
normal: 110 - 160 BPM
describe EFM variability for FHR
- absent: undetectable
- minimal: 5 or less
- moderate: 6 - 25
- marked: more than 25
what is the optimal variability for FHR on EFM?
moderate: 6-25
what is an acceleration (FHR on EFM)
fetus < 32 weeks:10 bpm in 10 seconds or less
fetus > 32 weeks: 15 bpm in 15 seconds or less
types of decelerations
1) early
2) late
3) variable
4) prolonged
prolonged acceleration
> 2 minutes but < 10 minutes
prolonged deceleration
> 2 minutes < 10 minutes
EFM bradycardia
rate: <110bpm
duration: >10 minutes
EFM tachycardia
rate: >160bpm
duration: >10 minutes
EFM tracing categories
- CAT 1: low risk of acid-base imbalance - normal baseline, moderate variability, +/- accels, +/- early decels
- CAT 2: indeterminate significance
- CAT 3: abnormal - likely abnormal acid-base balance - absent variability of baseline WITH recurrent late decels, recurrent variables, bradycardia OR sinusoidal pattern
VEAL CHOP
V-variable deceleration C-cord compression
E-early deceleration H-head compression
A-acceleration O-okay!
L-late deceleration P-placental insufficiency
Minimal variability of baseline:
can result from:
* fetal hypoxemia and metabolic acidemia
can also result from:
* fetal sleep cycles
* fetal tachycardia
* extreme prematurity
* medications that cause CNS depression
* congenital abnormalities
* preexisting neurologic injury
moderate variability of baseline:
considered normal - predicts normal fetal acid-base balance
Sinusoidal pattern in FHR baseline
- occurs with severe fetal anemia (uncommon)
- associated with chorioamnionitis, fetal sepsis, and administration of opioid analgesics
early deceleration
- gradual and occurs with contractions - head compressed by contraction
- onset of decel coincides with beginning of uterine contraction and recovery takes place when uterine contraction subsides
- decel is a uniform shape
late deceleration
- gradual and nadir occurs after peak of contraction - disruption of oxygen transfer
- periodic - occurs in relation to contractions
nadir
lowest point of a deceleration
variable deceleration
- abrupt onset - can occur at anytime and at variable intervals
- must be 15x15 to count
- episodic - occur with no particular relation to contractions
- occur due to umbilical cord compression
prolonged decelerations
last longer than 2 minutes
what is the L&D nurses role?
1) monitor fetus and uterine status throughout labor
2) chart fetal strip and uterine activity every 15-30 minutes
3) alert providers to concerning strips
4) intrauterine resuscitation
what may be involved with intrauterine resuscitation?
1) decrease or DC oxytocin
2) turn or reposition - left lateral offers best uteroplacental oxygenation
3) fluid bolus ~250-500mL
4) Terbutaline 0.25mg SC - tocolysis
5) 10L O2 via nonrebreather face mask
normal umbilical blood gas levels (artery)
pH: 7.2-7.3
pCO2: 45-55
pO2: 15-25
base deficit: <12
normal umbilical blood gas levels (vein)
pH: 7.3-7.4
pCO2: 35-45
pO2: 25-35
base deficit: <12
umbilical blood gas levels indicating fetal respiratory acidemia
pH: <7.2
pCO2: elevated
base deficit: <12
umbilical blood gas levels indicating fetal metabolic acidemia
pH: <7.2
pCO2: normal
base deficit: 12 or more
umbilical blood gas levels indicating fetal mixed acidemia
pH: <7.2
pCO2: elevated
base deficit: 12 or more
NST
non-stress test
describe non-stress test
- 20 minute strip
reactive > 2 accels in 20 minutes, normal baseline, moderate variability
non-reactive < 2 accels in 20 minutes, abnormal baseline, variability, or + decels
is a non-stress test is non-reactive what should be next?
further monitoring consider CST/BPP
CST
contraction stress test - provides warning of fetal compromise earlier than NST
describe a contraction stress test
- pt given oxytocin or nipple stim to cause contractions; oxytocin is titrated to achieve 3 contractions (lasting 40-60 seconds) in 10 minutes
negative no late decels
positive persistent and consistent late decels coinciding with more than half of the contractions
what does uterine contraction do to FHR?
reduces uterine blood flow–> reduces placental perfusion–>reduces O2 to fetus–> reduces FHR
when is an APGAR score done?
1 and 5 minutes after birth. if abnormal it will continue to be done till normal score achieved
APGAR scoring
teratogenic drugs
can cause deformities in babies
components of a quad screen:
1) MSAFP (maternal serum alpha-fetogrotein)
2) unconjugated estriol
3) hCG (human chorionic gonadotropin
4) dimeric inhibin A
when is the quad screen performed?
between 15-22 weeks
results of a quad test that indicate trisomy 21:
- MSAFP and unconjugated estriol decreased
- hCG and inhibin levels increased
results of a quad screen that indicate trisomy 18:
- MSAFP, unconjugated estriol, and hCG levels decreased
- inhibin not included in diagnosis
