ASSESSMENT OF HIGHRISK PREGNANCY
Chapter 10
Objectives
◦ Define the key terms relate to antenatal test
◦ Identify the purpose and indication for key antenatal tests
◦ Describe the procedure, interpretation, advantages, and risks of common antenatal tests
◦ Identify the nursing responsibilities related to key antenatal tests
◦ Identify patient teaching needs related to antenatal tests
Assessment of
Risk Factors
(page 225)
◦ Biophysical Factors
◦ Psychosocial
factors
◦ Sociodemographic
factors
◦ Environmental
factors
Biophysical
◦Includes risks factors that originate within the
mother/fetus which can affect the development
◦Genetic disorders
◦Nutritional
◦General health
◦Medical/obstetric related illness
Psychosocial Risk
◦ Maternal behaviors and adverse
lifestyles that have a negative effect on
the health of mother and fetus
◦ Emotional distress
◦ Hx of depression
◦ Mental health problems
◦ Unhealthy interpersonal relationships
(abuse)
◦ Smoking , caffeine, alcohol and drugs
Sociodemographic Risks
May place
mother and
fetus at risk
Lack of
prenatal care
Age
Low income
Single marital
status
Residence
Minority
ethnic group
Infections
Anesthetic gases
Radiation
Environmental
factors
Therapeutic drugs
Illicit drugs
Cigarette smoke
Stress
Diet
Antepartum testing
Identify fetuses at risk for
injury due to interrupted
acute or chronic
oxygenation, in order to
prevent permanent injury
or death
Second goals is to identify
appropriately oxygenated
fetuses so that
unnecessary intervention
can be avoided
Kick count, non-invasive and inexpensive
Daily Fetal
Movement
Count
Prescence of movement is normally and reassuring
sign
Decreased activity is noted in response to hypoxemia
Different protocols
• Once a day for 60 minutes
• 2-3 times/day for 2 hours or until 10 movements
• Count all fetal movements in a 12-hour period until 10 movements
• Fewer than 3 movements/hour needs further evaluation
• Assess nutrition and maternal position (lie on left) first
Ultrasonography
◦ Considered the most valuable diagnostic tool in obstetrics.
◦ Ultrasound can be performed abdominally or transvaginally
◦ Levels of ultrasonography
◦ Standard: most frequently done in 2nd and 3rd trimesters to evaluate
position/presentation, AFI, fetal growth
◦ Limited: to determine a specific piece of information re the
pregnancy re AFI (amniotic fluid index)
◦ Specialized: done when anatomical or physiological abnormality is
suspected
◦ Ultrasonography provides early diagnosis, that allows for plan of care
to be in place
◦ Fetal heart activity, GA, fetal growth, fetal anatomy, genetic disorders,
placental location
◦ Standard set of measurements are used
◦ Maximum embryo length of grownrump length
◦ Best done during first trimester
◦ After first trimester Biparietal diameter
(BPD), head circumference, abd
circumference and femur length is used
◦ Growth id determined by both
intrinsic growth potential and
environmental factors
Fetal Well-being
◦ Amniotic Fluid Index (AFI)
◦ Oligohydramnios < 5cm
◦ Fetal renal disease
◦ Congenital abnormalities
◦ PPROM
◦ Polyhydramnios > 25 cm
◦ Gastrointestinal and CNS anomalies
◦ Twin-to-twin transfusion
◦ Placental abnormalities
DOPPLER FLOW STUDIES
◦ Uses systolic/diastolic flow ratios and resistance
indices to estimate blood flow in various
arteries.
◦ Indicates fetal reserve and adaptation
◦ Absent or reversed flow are associated with
growth restriction
◦ Doppler flow studies reduce perinatal mortality
and unnecessary obstetric interventions
Biophysical Profile (BPP)
◦ A noninvasive assessment of fetus based on acute and chronic marker so fetal
disease
◦ Used in late 2nd and 3rd trimester for antepartum testing because its a reliable
predictor of fetal well-being
◦ Recommended for woman with increased risk of problems
◦ Done after 32 weeks GA
◦ A low score may indicate further testing
◦ In some case, early or immediate delivery may be indicated
◦ Tables 10.2 + 10.3, page 231
and
BIOPHYSICAL PROFILE (BPP)
Amniocentesis
◦ Done >15 weeks gestation
◦ A needle is inserted transabdominally into uterus and
amniotic fluid is withdrawn
◦ Indications include
◦ Alpha fetoprotein (AFP)
◦ prenatal diagnosis of genetic or congenital
disorders (NTD’s)
◦ Assessment of fetal ling maturity (L/S ratio;
presence of PG; LBC test)
◦ Risks/Complications
◦ Leaking of amniotic fluid
◦ Hemorrhage
◦ Infection
◦ Fetal death
Chorionic Villus
Sampling (CVS)
◦ Performed between 10-13 weeks
◦ Reflects the genetic make-up of the fetus
◦ Cannot be used for maternal serum maker
◦ Invasive
◦ Risks
◦ Chorioamnionitis
◦ PPROM
◦ Miscarriage
Alpha-Fetoprotein (AFP)
Screening tool for
Neural Tube Defects
(NTD)
85-92% o open
NTD’s and most
cases of anencephaly
can be detected early
Increased levels are
detectable beginning
week 7 GA
NTD occurs in
approximate in 1 in
1000 live births
AFP screening
should be done
between 16-18 weeks
gestation
AFP is produced in
the fetal
gestrointestinal tract
and liver
AFP is usually part
of the quad screen
Multiple Marker/Coombs
◦ Screening to detect fetal chromosomal abnormalities, trisomy 21 (Down syndrome)
◦ 11-14 weeks GA
◦ Measures pregnancy-associated plasma protein A (PAPP-A) and Human chorionic
gonadotrophin (B-hCG)
◦ Trisomy 21 hCG and NT is higher: PAPP-A levels are lower
◦ Trisomy 13 and 18, hCG and PAPP-A lower
◦ Coombs
◦ Screening tool for Rh alloisoimmunization
◦ If values are high: increased risk for hydrops fetalis
◦ 1:8 to 1:32 is critical – significant risk
Non-Stress Test
(NST)
◦ NST interpretation is either reactive or
nonreactive
◦ Acceleration of FHR and fetal movement
indication adequate oxygenation and an
intact CNS
◦ Reactive NST meets criteria of 2
accelerations of the FHR over 20 min
◦ If criteria not met test may be extended
for further 20 min
◦ Nonreactive test will require further
investigation
◦ Vibroacoustic Stimulation
Oxytocin challenge (OCT)
Identify jeopardized fetus that was stable at rest but showed evidence of
compromise after stress.
Uterine contraction decrease placenta perfusion
Contraction
Stress Test
If the decrease is sufficient to produce hypoxia in the fetus, a
deceleration in FHR results
Done with nipple stimulation of Oxytocin-stimulated contractions
Results are
•
•
•
•
•
••
•
Negative
Negative
Positive
Positive
Equivocal-suspicious
Equivocal-suspicious
Equivocal
Unsatisfactory
• Equivocal
• Unsatisfactory
◦ Negative- 3 contraction in 10 min with NO late
decelerations
CST
◦ Positive- repetitive persistent late deceleration
occurring with more than half of the contractions
◦ Equivocal- FHR decelerations with hyperstimulation
◦ Unsatisfactory- fewer that 3 contractions in 10 min