490 likes | 500 Views
Dr. archana vikram. PROCEDURE RELATED PREGNANCY LOSS RATE IS 1-2%. NON STRESS TEST. FHR accelerations with fetal movement – healthy fetus Valuable to identify fetal wellness rather than illness. Reactive- 2 / > accelerations of more than 15 beats/ min and > 15 sec in 20 min
E N D
NON STRESS TEST • FHR accelerations with fetal movement – healthy fetus • Valuable to identify fetal wellness rather than illness. • Reactive- 2 / > accelerations of more than 15 beats/ min and > 15 sec in 20 min • Non- reactive- absence of any reactivity. • Reactive NST –PND about 5 / 1000 • Nonreactive – PND about 40/1000
A normal, healthy fetal heart rate should possess average or moderate variability. Decreasing variability is an indicator of possible stress.
Accelerations: The fetal heart rate will normally remain steady or accelerate during uterine contractions.Look at the fetal heart rate and what is happening with contractions.
· An early deceleration begins at or after the onset of a contraction and returns to the baseline rate by the time the contraction has finished and produces a mirror image of the contraction. · Early decelerations are not a sign of fetal problems.
Late Decelerations: Late decelerations are transitory decreases in heart rate caused byuteroplacental insufficiency, a compromised blood flow to the baby that does not deliver the amount of oxygen needed to withstand the stress of labor. The late deceleration begins after the onset of the peak or middle of the contraction and ends after the contraction. · A late deceleration begins during or after a contraction and has not recovered by the time that the contraction has ended. A late deceleration indicates decreased blood flow during uterine contraction. Note: Persistent late decelerations are ominous
Variable Decelerations: Variable decelerations are transitory decreases in fetal heart rate caused by umbilical cord compression. A variable deceleration is unrelated to contractions. They mean umbilical cord compression. · They may appear V-shaped or U-shaped If the baseline fetal heart rate remains stable and the variability remains good, variable decelerations are not associated with poor fetal outcome. ·They indicate possible compromise if they become prolonged or are persistent.
Ultrasound • Quick, non-invasive procedure, easy interpretation • Customised fetal growth charts (serial scans) • Liquor volume • Placental function • Doppler study • Abnormal results correlate with increased risk of stillbirth and neonatal morbidity in selected pregnancies
Cochrane • Not enough evidence to evaluate the use of biophysical profile as a test of fetal well-being in high risk pregnancies except diabetes • No evidence of any benefit in screening • Errors associated with the BPP • Management decisions based on the score only. • Intervention based on a false positive low score • No intervention based on a false negative normal score • Management based on BPP without considering overall clinical findings.
Modified BPP • NST AND AFI • Abnormal- NST is non-reactive and AFI < 5
BPP and Perinatal morbidity • Significant inverse linear correlation (Manning, 1990) • Fetal distress • NICU admission • IUGR • 5 min Apgar <7 • Cord artery pH <7.20
Doppler velocimetry • 40% of combined ventricular output is directed to the placenta by umbilical arteries. • Assessment of umbilical blood flow provides information on blood perfusion of the fetoplacental unit. • Volume of flow increases and vascular impedance decreases with advancing Doppler velocimetry of the umbilical arteries gestational age. • Low vascular impedance allows a continuous forward blood flow throughout the cardiac cycle.
Doppler velocimetry • Uterine arteries – 24/40
Doppler study • Doppler velocimetry • A poor indicator of fetal compromise or adaptation to the placental abnormality but does identify patients at risk for increased perinatal mortality. • Strong association between high systolic to diastolic ratios and IUGR.