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Fetal Assessment. Litigation Cost of CTG Misinterpretation. In the ten years (2000-2010) covered by the study, 300 claims involving alleged CTG misinterpretation were reported to the NHSLA. The total value of these claims is estimated to be in the region of £466million.
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Litigation Cost of CTG Misinterpretation • In the ten years (2000-2010) covered by the study, 300 claims involving alleged CTG misinterpretation were reported to the NHSLA. The total value of these claims is estimated to be in the region of £466million. • 2,330,000,000,000 Toman, 2.3 trillion T or 2300 Billion T ( assuming 1£=5000 T) Source: NHSLA
Screening for high risk pregnancy History • * Age • *Social burden • *Smoking • *Past medical conditions e.g D.M, HTN • *Past Obstetric history
Fetal assessment Aim: Ensure fetal wellbeing ( Identify patients at risk of fetal asphyxia) To prevent prenatal mortality & morbidity
When to start fetal Assessment ** Risk assessed individually **For D.M. fetal assessment should start from 32 weeks onward if uncomplicated ***If complicated D.M. start at 24 weeks onward **For Post date pregnancy start at 40 weeks **For any patient with decrease fetal movement start immediately ** Fetal assessment is done once or twice weekly
FETAL AND NEONATAL COMPLICATIONS OF ANTEPARTUM ASPHYXIA Fetal Outcomes Neonatal Outcomes Stillbirth Mortality Metabolic acidosis at birth Metabolic acidosis Hypoxic renal damage Necrotizing enterocolitis Intracranial haemorrhage Seizures Cerebral palsy
CONDITIONS ASSOCIATED WITH INCREASED PERINATAL MORBIDITY/MORTALITY WHERE ANTENATAL FETAL TESTING MAY HAVE AN IMPACT Small for gestational age fetus Decreased fetal movement Postdates pregnancy (>294 days) Pre-eclampsia/chronic hypertension Pre-pregnancy diabetes Insulin requiring gestational diabetes Preterm premature rupture of membranes Chronic (stable) abruption
Cerebral Palsy • Cerebral palsy is a group of permanent disorders of the development of movement and posture, causing activity limitation, that are attributed to non-progressive disturbances that occurred in the developing fetal or infant brain. Source: cerebralpalsy.org
Fetal Assessment Fetal movement counting Non stress test Contraction stress test Ultrasound fetal assessment Umbilical Doppler Velocimetry
Fetal movement counting Cardiff technique: *Done in the morning, patient should *calculate how long it takes to have 10 fetal movement **10 movements should be appreciated in 12 hours
Fetal movement counting Sadovsky technique: -For one hour after meal the woman should lie down and concentrate on fetal movement -4 movement should be felt in one hour -If not , she should count for another hour -If after 2 hours four movements are not felt, she should have fetal monitoring
Non stress test *Done using the cardiotocometry with the patient in left lateral position **Record for 20 minutes
Non stress test *The base line 120-160 beats/minute *Reactive: At least two accelerations from base line of 15 bpm for at least 15 sec within 20 minutes Non reactive: No acceleration after 20 minutes- proceed for another 20 minutes
Non stress test If non reactive in 40 minutes---proceed for contraction stress test or biophysical profile The positive predictive value of NST to predict fetal acidosis at birth is 44%
A typical CTG output for a woman not in labour. A: Fetal heartbeat; B: Indicator showing movements felt by mother (caused by pressing a button); C: Fetal movement; D: Uterine contractions
Contraction stress test Fetal response to induced stress of uterine contraction and relative placental insufficiency Should not be used in patients at risk of preterm labor or placenta previa Should be proceeded by NST
Contraction stress test • Contraction is initiated by nipple stimulation or by oxytocin I.V. • The objective is 3 contractions in 10 minutes • If late deceleration occur-----positive CST
Interpretation of CTG Normal Baseline FHR 110–160 bpm – Moderate bradycardia 100–109 bpm – Moderate tachycardia 161–180 bpm – Abnormal bradycardia < 100 bpm – Abnormal tachycardia > 180 bpm
Deceleration • EARLY : Head compression • LATE : U-P Insufficiency • VARIABLE : Cord compression Primary CNS dysfunction
TachycardiaHypoxia ChorioamnionitisMaternal fever B-Mimetic drugsFetal anaemia,sepsis,ht failure,arrhythmias
INDEX 1. Internal Electronic Fetal Hearth Rate Monitoring 2. External (Indirect) Electronic Fetal Heart Rate Monitoring 3. Fetal Heart Rate Pattern - Baseline Fetal Heart Activity
INTERNAL ELECTRONIC FETAL HEART RATE MONITORING Standard fetal monitor tracing of heart rate using fetal scalp electrode shown at top. Bottom two tracings represent cardiac electrical complexes detected from fetal scalp and maternal chest wall electrodes. Spiking of the fetal rate in the monitor tracing is due to the premature atrial contractions. (F=fetus; M=mother; PAC=fetal premature atrial contraction.)
INTERNAL ELECTRONIC FETAL HEART RATE MONITORING Placental abruption: The fetal scalp electrode detected heart rate first of the dying fetus. After fetal death, the maternal ECG complex is detected and recorded.
EXTERNAL (INDIRECT) ELECTRONIC FETAL HEART RATE MONITORING ◎ External detectors to monitor fetal heart and uterine action ⇒ the necessity for membrane rupture and uterine invasion may be avoided ◎ FHR (fetal heart rate) ⇒ detected through the maternal abdominal wall using the ultrasound Doppler principle
FETAL HEART RATE PATTERNS • other cause : congenital heart block and serious fetal compromise Fetal bradycardia measured with a scalp electrode in a pregnancy complicated by placental abruption and subsequent fetal death.
FETAL HEART RATE PATTERNS B. Tachycardia • mild : 161 ~ 180 bpm severe : 181 bpm or more • cause maternal fever from amnionitis (m/c) fetal compromise cardiac arrhythmias parasympathetic (atropine) or sympathomimetic (terbutaline) drugs • fetal compromise with tachycardia ⇒ concomitant heart rate deceleration (key point)
FETAL HEART RATE PATTERNS 2) Beat-to-beat variability • an important index of cardiovascular function • regulated largely by the autonomic nervous system A. Short-term variability • instantaneous change in FHR from one beat to the next • time interval between cardiac systoles
FETAL HEART RATE PATTERNS B. Long-term variability • the oscillatory changes that occur during the course of 1 minute - result in waviness of the baseline - normal frequency : 3 ~ 5 cycle/min
FETAL HEART RATE PATTERNS • physiological and pathological processes (affect or interfere with beat-to-beat variability) ① fetal breathing ② fetal body movements ③ advancing gestation - after 30 wks, fetal inactivity → diminished variability activity → variability increased
FETAL HEART RATE PATTERNS ④ maternal acidemia - cause decreased fetal beat-to-beat variability ⑤ analgesic drugs given during labor - diminished variability (narcotics, barbiturates, phenothiazines, tranquilizer) - MgSO4 : decrease variability only in the third hour of the infusion : be deemed clinically insignificant : blunted the frequency of acceleration
FETAL HEART RATE PATTERNS Grades of baseline fetal heart rate variability. (1) Undetectable, absent variability; (2) minimal≤5 bpm variability; (3) moderate (normal), 6 to 25 bpm variability; (4) marked,>25 bpm variability; (5) sinusoidal pattern.
FETAL HEART RATE PATTERNS 3) Cardiac arrhythmia ◎ first suspected signs - baseline bradycardia - tachycardia - abrupt baseline spiking (m/c)
FETAL HEART RATE PATTERNS 4) Sinusoidal heart rates ◎ true sinusoidal pattern - observed with serious fetal anemia • from D-isoimmunization • ruptured vasa previa • fetomaternal hemorrhage • twin to twin transfusion ◎ insignificant sinusoidal pattern • administration of meperidine, morphine, alphaprodine, and butorphanol • amnionitis, fetal distress, and umbilical cord occlusion
FETAL HEART RATE PATTERNS ◎ pathophysiology of sinusoidal patterns is unclear Sinusoidal fetal heart rate pattern associated with maternal intravenous meperidine administration. Sine waves are occurring at a rate of 6 cycles/min.
Assessment of fetal growth by ultrasound Biometry: Biparietal diameter (BPD) Abdominal Circumference (AC) Femur Length (FL) Head Circumference (HC) Amniotic fluid • Placental localization