Post on 26-May-2017
Antepartum Fetal Surveillance
The primary goal - avoidance of intrauterine fetal death
Cornerstone of this assessment is to prevent fetal hypoxemia and acidemia
routine prenatal care populations with an increased risk of fetal
demise
Fetal Assessment
HIGH-RISKPREGNANCIES
1. FETAL• Anatomic anomaly• Decreased fetal movement• Heart block• Intraamniotic infection• Intrauterine growth restriction• Multiple gestation• Oligohydramnios
2. MATERNAL-FETAL
• Abruptio placenta• Abnormal serum screening (low PAPP-A, high M
SAFP)• Placenta previa, vasa previa• Postterm or postdates,premature rupture of fetal
membranes• Threatened preterm delivery
3. MATERNAL
• Advanced maternal age• Cardiac disease (severe)• GDM• Hypertension, chronic• Hypertension, gestational• Substance abuse• Systemic lupus erythematosis• Thyroid disease• Thrombophilia or thromboembolic disease
ASSESSMENTS FOR LOW-RISK PREGNANCIES• USG: Dating scan 1st trimester-Done as early as possible determination of fetal number fetal viability fetal position gestational age placental location amniotic fluid volume presence or absence of a maternal pelvic mass presence of gross fetal malformations
2nd Trimester USG
– Fetal anatomic screening
– specifically at 18 to 20 weeks’ gestation, when visualization of the anatomic features is adequate.
– identify sonographic markers of fetal aneuploidy
• SONOGRAPHIC GUIDANCE – for an invasive procedure as amniocentesis
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FETAL MOVEMENT COUNTING
• Quickening 16-22 wks• Fetal hypoxemia is typically associated wit
h a reduction in fetal activity• Usually after a meal when the fetus is mor
e active, if 10 movements are not detected in 1 hour, further testing is often recommended
• Costeffective first line screening test
FETAL ASSESSMENT IN HIGH-RISKPREGNANCIES
1. CARDIOTOCOGRAPHY2. NONSTRESS TEST3. CONTRACTION STRESS TEST4. ULTRASOUND5. GROWTH ASSESSMENT6. AMNIOTIC FLUID ASSESSMENT7. BIOPHYSICAL PROFILE8. DOPPLER
CARDIOTOCOGRAPHY
• Principle: fetal neurologic system, through its afferent and efferent networks, serves as a key mediator to demonstrate fetal well-being
• 3 basic elements
Term Characteristic
Description
Baseline Definition Mean fetal heart rate, rounded to increments of 5 beats/min (e.g. 140, 145);
Bradycardia <110 beats per minute
Tachycardia >160 beats per minute
Term Characteristic
Description
Variability Definition Fluctuations of the baseline heart rate;
Absent Undetectable
Minimal Undetectable to ≤5 beats/min
Moderate 6-25 beats/min
Marked >25 beats/min
Term Characteristic
Description
Acceleration Definition Abrupt increase ≥15 beats/min lasting ≥15 s
Prolonged ≥2 min and <10 min (≥10 min is a baseline change)
Term Characteristic
Description
Deceleration Definition Decreases in the fetal heart rate
Early Gradual decrease onset to nadir ≥30 s with contraction
Late Gradual decrease onset to nadir ≥30 s; nadir of deceleration occurring after peak of contraction
NST
• A normal NST : def: REACTIVE NST A 20-minute fetal heart rate tracing that contains
two heart rate accelerations lasting 15 seconds or longer that peak 15 beats or more above the baseline
• If abnormal extended upto 20-40 min• A nonreactive NST or an NST with specific abnormalit
ies (e.g., high or low baseline, decelerations) should be followed by a BPP
CONTRACTION STRESS TEST
• CST assesses the fetal heart rate response in the presence of contractions
• improves on the specificity and sensitivity of the NST by assessing the fetal response to stress.
ULTRASOUND
• Fetal echocardiography at 20 to 22 weeks’ gestation in all pregnancies at high-risk of a fetal cardiac malformation
• Dm,• drug,• cardiac lesion,• in vitro fertilisartion
3D ULTRASOUND• Surface rendering mode – craniofacial anomalies, intracranial lesion
s, spinal anomalies,ventral wall defects, and fetal tumors
• In early pregnancy: • more accurate measurements of the gestational sac, yolk sac, and crow
n-rump length• more accurate midsagittal view of the fetus for measuring nuchal transluc
ency.
• To measure tissue volume:• cervical insufficiency.
• measurement of placental volume in the first trimester may predict fetuses at risk of intrauterine growth restriction
GROWTH ASSESSMENT
• Four separate leopold maneuvers• Uterus can be palpated above the pelvic brim at approximately 12 w
eeks’ gestation. • Thereafter, fundal height should increase by approximately 1 cm per
week, reaching the level of the umbilicus at 20 to 22 weeks’ gestation.
• Between 20 and 32 weeks’ gestation, the fundal height (in centimeters, from the superior edge of the pubic symphysis) is approximately equal to the gestational age (in weeks)
• BPD gest age assessment in 2nd & 3rd trimester
AMNIOTIC FLUID ASSESSMENT
• AFI • semiquantitative method• <5 / >20
• Maximum vertical pocket• semiquantitative method• <2 / >10
FETAL ASSESSMENT IN HIGH-RISKPREGNANCIES
1. CARDIOTOCOGRAPHY2. NONSTRESS TEST3. CONTRACTION STRESS TEST4. ULTRASOUND5. GROWTH ASSESSMENT6. AMNIOTIC FLUID ASSESSMENT7. BIOPHYSICAL PROFILE8. DOPPLER
Element Criterion
Breathing ≥1 episode of breathing movements lasting 30seconds
Movement ≥3 discrete body or limb movements
Tone ≥1 episode of active extension and flexion oflimbs or trunk
Amniotic fluid ≥1 pocket of amniotic fluid measuring ≥2 cm intwo perpendicular planes
Nonstress test ≥2 fetal heart rate accelerations lasting ≥15 secondsover 20 minutes
• Fetal tone appears at 7.5 to 8.5 weeks,• Fetal movement at 9 weeks,• Fetal breathing at 20 to 22 weeks,• FHR reactivity at 24 to 28 weeks’ gestation
Order of appearance
FETAL ASSESSMENT IN HIGH-RISKPREGNANCIES
1. CARDIOTOCOGRAPHY2. NONSTRESS TEST3. CONTRACTION STRESS TEST4. ULTRASOUND5. GROWTH ASSESSMENT6. AMNIOTIC FLUID ASSESSMENT7. BIOPHYSICAL PROFILE8. DOPPLER
• Decreased diastolic flow suggests increased placental vascular resistance and fetal compromise.
• Severely abnormal umbilical artery doppler velocimetry (defined as absent or reversed diastolic flow) is an especially ominous observation and is associated with poor perinatal outcome,
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