F etal M onitoring

Fetal MonitoringFetal Monitoring

Dr Ameya PurandareAssociate Professor,

Somaiya Medical college, Mumbai.Consultant,

Masina Hospital, Mumbai

Dr Ameya PurandareAssociate Professor,

Somaiya Medical college, Mumbai.Consultant,

Masina Hospital, Mumbai

CONCEPTCONCEPT L/F Fetal well being vs. Fetal distressL/F Fetal well being vs. Fetal distress

Re AssureRe Assure

Intervene before its too lateIntervene before its too late

High risk pregnanciesHigh risk pregnancies

DECREASE PERINATAL MORTALITYDECREASE PERINATAL MORTALITY

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Two thirds of fetal deaths occur before the Two thirds of fetal deaths occur before the

onset of labor.onset of labor. Many antepartum deaths occur in women at Many antepartum deaths occur in women at

risk for uteroplacental insufficiency.risk for uteroplacental insufficiency. Ideal test: allows intervention before fetal Ideal test: allows intervention before fetal

death or damage from asphyxia.death or damage from asphyxia.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Methods for antepartum fetal assessmentMethods for antepartum fetal assessment

Fetal movement countingFetal movement counting

Assessment of uterine growthAssessment of uterine growth

Antepartum fetal heart rate testingAntepartum fetal heart rate testing

Biophysical profileBiophysical profile

Doppler velocimetryDoppler velocimetry

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Uteroplacental insufficiencyUteroplacental insufficiency

Inadequate delivery of nutritive or respiratory Inadequate delivery of nutritive or respiratory substances to appropriate fetal tissues.substances to appropriate fetal tissues.

Inadequate exchange within the placenta due to Inadequate exchange within the placenta due to decreased blood flow, decreased surface area or decreased blood flow, decreased surface area or increased membrane thickness.increased membrane thickness.

Inadequate maternal delivery of nutrients or Inadequate maternal delivery of nutrients or oxygen to the placenta or to problems of oxygen to the placenta or to problems of inadequate fetal uptake.inadequate fetal uptake.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Theoretical scheme of fetal deteriorationTheoretical scheme of fetal deterioration

Fetal well being Fetal well being Nutritional compromiseNutritional compromise Fetal growth retardation Fetal growth retardation Fetal hypoxia with stress Fetal hypoxia with stress Decreasing respiratory functionDecreasing respiratory function Profound respiratory compromiseProfound respiratory compromise AsphyxiaAsphyxia DeathDeath

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Conditions placing the fetus at risk for UPIConditions placing the fetus at risk for UPI

Preeclampsia, chronic hypertension,Preeclampsia, chronic hypertension, Collagen vascular disease, diabetes mellitus, renal Collagen vascular disease, diabetes mellitus, renal

disease,disease, Fetal or maternal anemia, blood group sensitization,Fetal or maternal anemia, blood group sensitization, Hyperthyroidism, thrombophilia, cyanotic heart disease,Hyperthyroidism, thrombophilia, cyanotic heart disease, Postdate pregnancy,Postdate pregnancy, Fetal growth restrictionFetal growth restriction

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING


Maternal perception of a decrease in fetal Maternal perception of a decrease in fetal movements may be a sign of impending fetal death.movements may be a sign of impending fetal death.

It costs nothing.It costs nothing.

In a systematic fashion, especially in low risk In a systematic fashion, especially in low risk populations, may detect unsuspected fetal jeopardy.populations, may detect unsuspected fetal jeopardy.



3 movements in 30 minutes (Sadovsky).3 movements in 30 minutes (Sadovsky).

Elapsed time to register 10 fetal Elapsed time to register 10 fetal movements movements CARDIFFS COUNT TO 10CARDIFFS COUNT TO 10

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Assessment of uterine growthAssessment of uterine growth

General rule: fundal height in centimeters will equal the weeks of General rule: fundal height in centimeters will equal the weeks of gestation.gestation.

Exceptions: maternal obesity, multiple gestation, polyhydramnios, Exceptions: maternal obesity, multiple gestation, polyhydramnios, abnormal fetal lie, oligohydramnios, low fetal station, and fetal abnormal fetal lie, oligohydramnios, low fetal station, and fetal growth restriction.growth restriction.

Abnormalities of fundal height should lead to further investigation.Abnormalities of fundal height should lead to further investigation.

Accuracy: poor?Accuracy: poor?

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING When to begin testingWhen to begin testing

Single factor with minimal to moderate increased risk for Single factor with minimal to moderate increased risk for antepartum fetal death: 32 weeks.antepartum fetal death: 32 weeks.

Highest maternal risk factors: 26 weeks.Highest maternal risk factors: 26 weeks.

When estimated fetal maturity is sufficient to expect a When estimated fetal maturity is sufficient to expect a reasonable chance of survival should intervention be reasonable chance of survival should intervention be necessary.necessary.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Which test to use?Which test to use?

Contraction stress testContraction stress test

Low incidence of unexpected fetal deathLow incidence of unexpected fetal death

Increase in time, cost and inconvenienceIncrease in time, cost and inconvenience

Nonstress testNonstress test

Biophysical profile, modified biophysical profileBiophysical profile, modified biophysical profile

Doppler velocimetryDoppler velocimetry

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Contraction stress test (CST)Contraction stress test (CST)

Uterine contractions producing an intra-amniotic pressure in Uterine contractions producing an intra-amniotic pressure in excess of 30 mm Hg create an intra-myometrial pressure that excess of 30 mm Hg create an intra-myometrial pressure that exceeds mean intra-arterial pressure, therefore temporarily exceeds mean intra-arterial pressure, therefore temporarily halting uterine blood flow.halting uterine blood flow.

A hypoxic fetus will manifest late decelerations.A hypoxic fetus will manifest late decelerations.

Late decelerations correlate with stillbirth, IUGR, and low Late decelerations correlate with stillbirth, IUGR, and low Apgar scores.Apgar scores.

Oxytocin challenge test (OCT) (Ray 1972)Oxytocin challenge test (OCT) (Ray 1972)

Breast (nipple) stimulationBreast (nipple) stimulation

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING How to perform the CSTHow to perform the CST

External monitors for contraction and FHR External monitors for contraction and FHR measurement applied.measurement applied.

Patient in semi-fowler position or left lateral tilt (to Patient in semi-fowler position or left lateral tilt (to minimize supine hypotension).minimize supine hypotension).

Protocol for oxytocin infusion or breast stimulation.Protocol for oxytocin infusion or breast stimulation. Goal: three contractions in ten minutes.Goal: three contractions in ten minutes.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Interpretation of the CSTInterpretation of the CST

Negative: no late decelerations and adequate FHR Negative: no late decelerations and adequate FHR recordingrecording

Positive: Late decelerations present with the Positive: Late decelerations present with the majority of contractions (without excessive uterine majority of contractions (without excessive uterine activity)activity)

Equivocal test results: Suspicious, hyperstimulation, Equivocal test results: Suspicious, hyperstimulation, unsatisfactory.unsatisfactory.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Interpretation of the CSTInterpretation of the CST

Suspicious: Late decelerations are present with less Suspicious: Late decelerations are present with less than half of the contractions.than half of the contractions.

Hyperstimulation: Decelerations after contractions Hyperstimulation: Decelerations after contractions lasting more than 90 seconds, or with contraction lasting more than 90 seconds, or with contraction frequency greater than every 2 minutes.frequency greater than every 2 minutes.

Unsatisfactory: Cannot induce adequate contractions Unsatisfactory: Cannot induce adequate contractions or FHR recording is of poor quality.or FHR recording is of poor quality.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING OtherOther patterns patterns

Variable decelerations: consider oligohydramnios or Variable decelerations: consider oligohydramnios or cord entrapment.cord entrapment.

Loss of variability and blunting of decelerations: Loss of variability and blunting of decelerations: ominous sign.ominous sign.

Sinusoidal pattern: ominous pattern. Fetal anemia or Sinusoidal pattern: ominous pattern. Fetal anemia or fetal-maternal hemorrhage.fetal-maternal hemorrhage.

Nonreactive negative CST: should not occur, Nonreactive negative CST: should not occur, preexisting CNS abnormality?preexisting CNS abnormality?

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Management of CSTManagement of CST

Negative test: repeated weeklyNegative test: repeated weekly

Positive test: acted on according to clinical Positive test: acted on according to clinical conditioncondition

Equivocal test: repeat test the next dayEquivocal test: repeat test the next day

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING When to shorten the interval between testingWhen to shorten the interval between testing

Deterioration in diabetic controlDeterioration in diabetic control

Worsening hypertensionWorsening hypertension

Need to introduce antihypertensive medicationNeed to introduce antihypertensive medication

Decreased fetal movementDecreased fetal movement

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Contraindications to CSTContraindications to CST

PROMPROM Previous classical cesarean deliveryPrevious classical cesarean delivery Placenta previaPlacenta previa Incompetent cervixIncompetent cervix History of premature labor in this pregnancyHistory of premature labor in this pregnancy Multiple gestationMultiple gestation

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Contraction stress testContraction stress test

Corrected perinatal mortality rate: 1.2 / 1000Corrected perinatal mortality rate: 1.2 / 1000

High equivocal rateHigh equivocal rate

False positive rate: 8 to 57%False positive rate: 8 to 57%

False negative rate: 0.4 / 1000False negative rate: 0.4 / 1000

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Nonstress test (NST)Nonstress test (NST)

Healthy fetuses display normal oscillations and Healthy fetuses display normal oscillations and fluctuations of the baseline FHR (Hammacher, 1966; fluctuations of the baseline FHR (Hammacher, 1966; Kubli, 1969).Kubli, 1969).

Absence of these patterns was associated with Absence of these patterns was associated with increase in neonatal depression and perinatal increase in neonatal depression and perinatal mortality.mortality.

Accelerations of the FHR during stress testing Accelerations of the FHR during stress testing correlated with fetal well being (Trierweiler, 1976).correlated with fetal well being (Trierweiler, 1976).


Accelerations of the FHR occur with fetal movement, Accelerations of the FHR occur with fetal movement, uterine contractions, or in response to external stimuli.uterine contractions, or in response to external stimuli.

FHR accelerations appear to be a reflection of CNS FHR accelerations appear to be a reflection of CNS alertness and activity.alertness and activity.

Absence of FHR accelerations seems to depict CNS Absence of FHR accelerations seems to depict CNS depression caused by hypoxia, drugs, fetal sleep, or depression caused by hypoxia, drugs, fetal sleep, or congenital anomalies. congenital anomalies.


The endpoint of the NST is the presence or absence of The endpoint of the NST is the presence or absence of FHR accelerations within a specified period of time.FHR accelerations within a specified period of time.

Most clinicians use 2 accelerations of 15 beats per minute Most clinicians use 2 accelerations of 15 beats per minute (BPM) for 15 seconds in a 20-minute period.(BPM) for 15 seconds in a 20-minute period.

A healthy fetus < 32 weeks’ gestation may not have the A healthy fetus < 32 weeks’ gestation may not have the reactivity or the accelerations that meet the criteria of 15 reactivity or the accelerations that meet the criteria of 15 BPM for 15 seconds.BPM for 15 seconds.

The more remote from term, the more likely that The more remote from term, the more likely that nonreactivity will be due to fetal prematurity.nonreactivity will be due to fetal prematurity.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Performing the NSTPerforming the NST

External monitors for contraction and FHR External monitors for contraction and FHR measurement applied.measurement applied.

Patient in semi-fowler position or left lateral tilt Patient in semi-fowler position or left lateral tilt (to minimize supine hypotension).(to minimize supine hypotension).

Fetal movement is recorded.Fetal movement is recorded.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Interpreting the NSTInterpreting the NST

Reactive: 2 or more accelerations in 20 minutes.Reactive: 2 or more accelerations in 20 minutes. Accelerations: an increase of at least 15 BPM above Accelerations: an increase of at least 15 BPM above

the baseline lasting at least 15 seconds.the baseline lasting at least 15 seconds.

Fetal sound stimulation may be used to elicit a Fetal sound stimulation may be used to elicit a response.response.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Interpreting the NSTInterpreting the NST

Non reactive: Less than 2 accelerations in a 20-Non reactive: Less than 2 accelerations in a 20-minute period.minute period. May extend the testing period to 40 minutes or perform a May extend the testing period to 40 minutes or perform a

back-up test.back-up test.

There is no universal agreement on the number of There is no universal agreement on the number of accelerations required to consider the test reactive.accelerations required to consider the test reactive.

Reactive/Nonreactive with decelerations: Reactive/Nonreactive with decelerations: individualize managementindividualize management


Nonstress testNonstress test Perinatal mortality: 6.2/1000Perinatal mortality: 6.2/1000

False positive rate: 50%False positive rate: 50%

False negative rate: 3.2 / 1000False negative rate: 3.2 / 1000

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Biophysical profile (BPP)Biophysical profile (BPP)

Described by Manning (1980)Described by Manning (1980) The number of biophysical activities that could be The number of biophysical activities that could be

recorded increased with real time ultrasound: recorded increased with real time ultrasound: Fetal movement (FM)Fetal movement (FM)

Fetal tone (FT)Fetal tone (FT)

Fetal breathing movements (FB)Fetal breathing movements (FB)

Amniotic fluid volume (AFV)Amniotic fluid volume (AFV)

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Biophysical profile (BPP) – variablesBiophysical profile (BPP) – variables

NST: reactive – as described earlier.NST: reactive – as described earlier. FBM: present - at least 1 episode of at least 30 seconds FBM: present - at least 1 episode of at least 30 seconds

duration (within a 30 minute period).duration (within a 30 minute period). FM: present - at least 3 discrete episodes.FM: present - at least 3 discrete episodes. FT: normal - at least 1 episode of extension of FT: normal - at least 1 episode of extension of

extremities or spine with return to flexion.extremities or spine with return to flexion. AFV: normal – largest pocket of fluid greater than 1 cm AFV: normal – largest pocket of fluid greater than 1 cm

in vertical diameter.in vertical diameter.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Biophysical profile (BPP) Biophysical profile (BPP)

Each variable Each variable When normal: 2When normal: 2

When abnormal: 0When abnormal: 0

Highest Score: 10, Lowest Score: 0Highest Score: 10, Lowest Score: 0 Accuracy improved by increasing the number of Accuracy improved by increasing the number of

variables assessed.variables assessed. Overall false negative rate: 0.6/1000Overall false negative rate: 0.6/1000


Acute markers of fetal compromise: NST, FT, FBM, FMAcute markers of fetal compromise: NST, FT, FBM, FM

Chronic marker of fetal compromise: AFVChronic marker of fetal compromise: AFV

Nervous impulses that initiate fetal biophysical Nervous impulses that initiate fetal biophysical activities arise from different anatomic sites within the activities arise from different anatomic sites within the brain.brain.


Activities that become active first in fetal Activities that become active first in fetal development (FT, FM) are the last to disappear when development (FT, FM) are the last to disappear when asphyxia arrests all activities.asphyxia arrests all activities.

Activities that become active later in gestation Activities that become active later in gestation (NST,FBM) will be abolished 1(NST,FBM) will be abolished 1stst in cases of hypoxia in cases of hypoxia and acidosis.and acidosis.


Fetal tone: 7.5 to 8.5 weeksFetal tone: 7.5 to 8.5 weeks

Fetal movement: 9 weeksFetal movement: 9 weeks

Fetal breathing: 20 to 21 weeksFetal breathing: 20 to 21 weeks

NST: 24 to 28 weeksNST: 24 to 28 weeks


When hypoxia and acidosisWhen hypoxia and acidosis Late decelerations appear (CST)Late decelerations appear (CST) Accelerations disappear (CST, NST, BPP)Accelerations disappear (CST, NST, BPP) Fetal breathing stops (BPP)Fetal breathing stops (BPP) Fetal movement ceases (BPP, FMC)Fetal movement ceases (BPP, FMC) Fetal tone absent (BPP)Fetal tone absent (BPP)

Assessment of fetal well-being in high risk Assessment of fetal well-being in high risk pregnanciespregnancies Reduced perinatal mortality rate from 65/1000 to 5/1000 Reduced perinatal mortality rate from 65/1000 to 5/1000

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING BPP and perinatal mortality (PNMR)BPP and perinatal mortality (PNMR)

12,000 pregnancies (Manning, 1985)12,000 pregnancies (Manning, 1985)

BPP Score Corrected PNMRBPP Score Corrected PNMR 8-10 0.68-10 0.6 6 0.06 0.0 4 22.04 22.0 2 42.62 42.6 0 187.00 187.0

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING BPP and perinatal morbidityBPP and perinatal morbidity

Significant inverse linear correlation (Manning, 1990)Significant inverse linear correlation (Manning, 1990)

Fetal distressFetal distress

NICU admissionNICU admission

IUGRIUGR

5 min Apgar <75 min Apgar <7

Cord artery pH <7.20Cord artery pH <7.20

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING BPP without NSTBPP without NST

When the FM, FBM, FT, and AFV were normal (BPP 8/8), the When the FM, FBM, FT, and AFV were normal (BPP 8/8), the probability of a nonreactive NST was exceedingly small probability of a nonreactive NST was exceedingly small (Manning, 1987)(Manning, 1987)

The addition of NST did not improve prediction of outcome.The addition of NST did not improve prediction of outcome. BPP corrected PNMR false negative rateBPP corrected PNMR false negative rate

8/8 1.43 / 1000 0.73 / 10008/8 1.43 / 1000 0.73 / 1000

10/10 1.9 / 1000 0.65 / 100010/10 1.9 / 1000 0.65 / 1000

Selective use of NST saves time: only 2.7% patients need itSelective use of NST saves time: only 2.7% patients need it


Normal variables are highly predictive of a good neonatal Normal variables are highly predictive of a good neonatal outcome (Vintzileos, 1983).outcome (Vintzileos, 1983).

Each abnormal variable was associated with a high false Each abnormal variable was associated with a high false positive ratepositive rate

Variables Best predictor ofVariables Best predictor of Absence of FM abnormal FHR in labor (80%)Absence of FM abnormal FHR in labor (80%) NR NST meconium (33%)NR NST meconium (33%) Decreased AFV fetal distress (37.5%)Decreased AFV fetal distress (37.5%) Poor FT perinatal death (42.8%)Poor FT perinatal death (42.8%)


Combinations of variables increase the specificity of Combinations of variables increase the specificity of the testing, and increase the ability to predict the the testing, and increase the ability to predict the fetus in jeopardy (Vintzileos, 1983)fetus in jeopardy (Vintzileos, 1983) NR NST, BPP 6-7: fetal distress (20%)NR NST, BPP 6-7: fetal distress (20%)

NR NST, BPP 4: fetal distress (100%), deaths (0)NR NST, BPP 4: fetal distress (100%), deaths (0)

BPP 1-3: perinatal deaths (57%)BPP 1-3: perinatal deaths (57%)

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING BPP and NST in relation to fetal outcome (Vintzileos, 1983)BPP and NST in relation to fetal outcome (Vintzileos, 1983)

If reactive NST, then BPP If reactive NST, then BPP >> 8 in 95% of cases. 8 in 95% of cases. If BPP < 5, then no instances of reactive NST.If BPP < 5, then no instances of reactive NST. If nonreactive NST, then BPP If nonreactive NST, then BPP >> 8 in 39% of cases. 8 in 39% of cases. All hypoxic fetuses had nonreactive NST and absent fetal All hypoxic fetuses had nonreactive NST and absent fetal

breathing.breathing. A reactive NST was associated with good outcome in all A reactive NST was associated with good outcome in all

cases.cases.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Errors associated with the BPPErrors associated with the BPP

Management decisions based on the score only.Management decisions based on the score only. Intervention based on a false positive low scoreIntervention based on a false positive low score No intervention based on a false negative normal scoreNo intervention based on a false negative normal score

Management based on BPP without considering Management based on BPP without considering overall clinical findings.overall clinical findings.

Poor timing of testing.Poor timing of testing. Not including the NST.Not including the NST. Inexperience operators, poor technique, poor Inexperience operators, poor technique, poor

equipment.equipment.


When the FHR accelerates, there is virtually always When the FHR accelerates, there is virtually always fetal movement (FM)fetal movement (FM)

If the NST is reactive, there is fetal movement (FM) If the NST is reactive, there is fetal movement (FM) and tone (FT)and tone (FT)

If the NST is reactive, do not need the ultrasound If the NST is reactive, do not need the ultrasound parameters of the BPPparameters of the BPP

Only the AFV would add additional information Only the AFV would add additional information

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Modified biophysical profile (BPP)Modified biophysical profile (BPP)

A standard NST is combined with an amniotic fluid index A standard NST is combined with an amniotic fluid index (AFI)(AFI)

Negative: Reactive NST / AFI > 5.0 cmNegative: Reactive NST / AFI > 5.0 cm If NST is nonreactive or has decelerations, or if the AFI is If NST is nonreactive or has decelerations, or if the AFI is <<

5.0 cm, then a BPP is performed.5.0 cm, then a BPP is performed. Negative results are repeated every 3 to 4 days.Negative results are repeated every 3 to 4 days. If the AFI > 5.0 cm, a repeat AFI may be done in one week. If the AFI > 5.0 cm, a repeat AFI may be done in one week.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Primary fetal surveillancePrimary fetal surveillance

There have been no adequate prospective There have been no adequate prospective randomized studies comparing the various testing randomized studies comparing the various testing modalities.modalities.

The final decision regarding choice of fetal The final decision regarding choice of fetal surveillance test is most often determined by surveillance test is most often determined by institutional preference and experience.institutional preference and experience.

All forms of fetal testing are valuable and need to be All forms of fetal testing are valuable and need to be interpreted cautiously with full knowledge of the interpreted cautiously with full knowledge of the specific test limitations.specific test limitations.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Primary fetal surveillancePrimary fetal surveillance

NST: The most popular method NST: The most popular method Easy to perform, easy to interpret, has fewer equivocal Easy to perform, easy to interpret, has fewer equivocal

results, has excellent patient and physician acceptance.results, has excellent patient and physician acceptance. BPP as a back up test.BPP as a back up test.

BPP: BPP: Can identify oligohydramnios and anomalous babies. Can identify oligohydramnios and anomalous babies. Antepartum death rate is less than with the NST. Antepartum death rate is less than with the NST.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Doppler velocimetry of the umbilical arteriesDoppler velocimetry of the umbilical arteries

40% of combined ventricular output is directed to the 40% of combined ventricular output is directed to the placenta by umbilical arteries.placenta by umbilical arteries.

Assessment of umbilical blood flow provides information Assessment of umbilical blood flow provides information on blood perfusion of the fetoplacental unit.on blood perfusion of the fetoplacental unit.

Volume of flow increases and vascular impedance Volume of flow increases and vascular impedance decreases with advancing gestational age.decreases with advancing gestational age.

Low vascular impedance allows a continuous forward Low vascular impedance allows a continuous forward blood flow throughout the cardiac cycle.blood flow throughout the cardiac cycle.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Doppler velocimetryDoppler velocimetry

An increase in the vascular resistance of the fetoplacental An increase in the vascular resistance of the fetoplacental unit leads to a decrease in end diastolic flow velocity or unit leads to a decrease in end diastolic flow velocity or its absence in the flow velocity waveform.its absence in the flow velocity waveform.

Abnormal waveforms reflect the presence of a structural Abnormal waveforms reflect the presence of a structural placental lesion.placental lesion.

Abnormal Doppler results require specific management Abnormal Doppler results require specific management protocols and intensive fetal surveillance.protocols and intensive fetal surveillance.

ANTEPARTUM FETAL MONITORINGANTEPARTUM FETAL MONITORING Doppler velocimetryDoppler velocimetry

A poor indicator of fetal compromise or A poor indicator of fetal compromise or adaptation to the placental abnormality but does adaptation to the placental abnormality but does identify patients at risk for increased perinatal identify patients at risk for increased perinatal mortality.mortality.

Strong association between high systolic to Strong association between high systolic to diastolic ratios and IUGR.diastolic ratios and IUGR.

CTGCTG

4 Parameters4 Parameters1.1. Baseline FHRBaseline FHR2.2. Beat to beat variabilityBeat to beat variability

Short termShort term Long termLong term

3.3. AccelerationsAccelerations4.4. DecelerationsDecelerations

EarlyEarly LateLate VariableVariable

DOPPLERDOPPLER

Uterine arteryUterine artery

Uterine arteryUterine artery

Umblical arteryUmblical artery




MCAMCA

Ductus VenosusDuctus Venosus

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