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Doppler of the Uterine and Umbilical Arteries- Clinical Significance

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					Doppler of the Uterine
          And
  Umbilical Arteries:
 Clinical Significance
     Greggory R. DeVore MD
 Part I: The Use of
the Umbilical Artery
Doppler in High- and
 Low-Risk Patients
Historical Perspective

First use of Doppler ultrasonography
    to study flow velocity in the fetal
    umbilical artery was reported in
                  1977

       Fitzgerald and Drumm. Non-invasive measurement
      of human circulation using ultrasound: a new method.
                        BMJ 1977, 2:1450
Historical Perspective

Observational Studies:
 Association between reduced end-
  diastolic umbilical artery velocities and
  increased vascular resistance in the
  fetoplacental circulation
Historical Perspective

Observational Studies:
 Complications of pregnancy associated
  with placental pathologic mechanisms
 Adverse pregnancy outcome including
  perinatal death
Historical Perspective

Other Doppler Studies:
 Uterine arteries
 Middle Cerebral arteries
 Venous system
Historical Perspective

Benefit of Umbilical Artery Evaluation
 Less experienced operators can
  achieve highly reproducible results with
  simple, inexpensive continuous-wave
  equipment
Historical Perspective

Problem With Observational Studies
 Observations are often rushed into
  clinical practice only to find later that
  they are either ineffective or even
  harmful
Historical Perspective

Randomized Controlled Trials
 “Gold Standard” for evaluating the
  effectiveness of clinical investigations in
  the human population
 “Meta Analysis” combines the results
  from smaller trials of similar structure
  and purpose.
Historical Perspective

Randomized Controlled Studies
 Doppler ultrasonography has been
  subjected to more rigorous and
  extensive assessment by randomized
  controlled trials than any previous test
  of fetal health or fetalplacental function
Meta-Analysis In
High-Risk Pregnancies

  Doppler Ultrasonography in High-Risk
  Pregnancies: Systematic Review With
  Meta-Analysis
  Alfirevic Z and Neilson JP
  Doppler ultrasonography in high-risk pregnancies: Systematic
  review with meta-analysis
  Am J Obstet Gynecol 1995, 172:1379
                                                              High-Risk


Meta-Analysis

    Studies Included In Analysis
   Trudinger et al 1987       Biljan et al 1992
   McPharland et al 1988      Johnstone et al 1993
   Hofmeyr et al 1991         Pattison et al 1994
   Newham et al 1991          Neales et al
   Burke et al 1992            (Unpublished)
   Almstrom et al 1992        Nienhuis (Unpublished)



                                       Alfirevic Z and Neilson JP
                                       Am J Obstet Gynecol 1995, 172:1379
                                          High-Risk


Meta-Analysis

      Number Evaluated

         7,474

                   Alfirevic Z and Neilson JP
                   Am J Obstet Gynecol 1995, 172:1379
                                         High-Risk


Meta-Analysis

    Absent
  End-Diastolic
      Flow


   5.6%
                  Alfirevic Z and Neilson JP
                  Am J Obstet Gynecol 1995, 172:1379
                                                    High-Risk


Meta-Analysis: Results

Perinatal Deaths
 Clinical action guided by Doppler
  ultrasonography reduced the odds of
  perinatal death by 38%, with a 95%
  confidence interval of 15% to 55%
 10 of 12 studies demonstrated a
  reduction in death compared to controls

                             Alfirevic Z and Neilson JP
                             Am J Obstet Gynecol 1995, 172:1379
                                                    High-Risk


Meta-Analysis: Results

Antenatal Care and Labor
 Reduction in antenatal admissions
 Reduction in inductions of labor
 Reduction of cesarean section for fetal
  distress during labor



                             Alfirevic Z and Neilson JP
                             Am J Obstet Gynecol 1995, 172:1379
                                                    High-Risk


Meta-Analysis: Results

   Neonatal Outcome
    No effect on perinatal morbidity
    No difference in birth weight




                             Alfirevic Z and Neilson JP
                             Am J Obstet Gynecol 1995, 172:1379
                                                    High-Risk


Meta-Analysis: Results

 Other Outcomes
  Reduction of 16% in the number of
   elective deliveries
  Reduction of 31% of fetal distress
   during labor
  Reduction of 87% of hypoxic
   encephalopathy
                             Alfirevic Z and Neilson JP
                             Am J Obstet Gynecol 1995, 172:1379
                                               High-Risk


Meta-Analysis:
Conclusions
  Should additional studies be
  ethically done in light of the
  current results?



                        Alfirevic Z and Neilson JP
                        Am J Obstet Gynecol 1995, 172:1379
                                                   High-Risk


Meta-Analysis:
Conclusions
It is likely that, on the basis of
available information, parents with
high-risk pregnancies may not wish to
enter their babies in further trials and
deny them the possibility of
investigation by a test that clearly
increases their chance of survival.
                            Alfirevic Z and Neilson JP
                            Am J Obstet Gynecol 1995, 172:1379
Randomized Controlled Trial
In Low-Risk Pregnancies

  A Randomized Controlled Trial of
  Doppler Ultrasound Velocimetry of the
  Umbilical Artery in Low-Risk
  Pregnancies
  Doppler French Study Group
  Br J Obstet Gynecol 1997, 104:419
                                             Low-Risk


Historical Perspective


  Studies in unselected low-risk
  patients have not been
  conclusive.



                        Doppler French Study Group
                        Br J Obstet Gynecol 1997, 104:419
                                             Low-Risk


Historical Perspective


  In France the use of the
  umbilical artery Doppler in
  high-risk pregnancies is
  accepted and widespread.


                        Doppler French Study Group
                        Br J Obstet Gynecol 1997, 104:419
                                              Low-Risk


Historical Perspective


 There has been a trend toward
 the extension of its indications,
 especially at the time of early
 third trimester ultrasonography


                         Doppler French Study Group
                         Br J Obstet Gynecol 1997, 104:419
                                            Low-Risk


Historical Perspective

 For this reason, a multicenter
 randomized trial to evaluate
 the benefits of umbilical
 Doppler performed between 28
 and 34 weeks of gestation in a
 population of low risk women

                       Doppler French Study Group
                       Br J Obstet Gynecol 1997, 104:419
                                             Low-Risk


Methods

 All normal women between 28
 and 34 weeks of gestation
 were asked to participate in the
 study



                        Doppler French Study Group
                        Br J Obstet Gynecol 1997, 104:419
                                                  Low-Risk


Methods
 Women Excluded For:
 Medical  history of hypertension
 Medical history of diabetes
 Obstetric history of fetal death
 History of IUGR
 Women who had undergone umbilical
 artery Doppler before 28 weeks


                             Doppler French Study Group
                             Br J Obstet Gynecol 1997, 104:419
                                                    Low-Risk


Methods
 Study Design:
   Time of the Study: 1988-1990
   20 Antenatal Clinics throughout France
   Control group: No Doppler studies
   Doppler group: Results of Doppler
   conveyed to physicians




                               Doppler French Study Group
                               Br J Obstet Gynecol 1997, 104:419
                                                     Low-Risk


Methods
 Assessment of Pregnancy Care
   Number   of antenatal visits
   Days of antenatal hospitalization
   Cardiotocography measurements
   Rate of pregnancy induced
   hypertension




                                Doppler French Study Group
                                Br J Obstet Gynecol 1997, 104:419
                                               Low-Risk


Methods
 Assessment of Pregnancy Care
   Rate of pre-eclampsia
   Rate of uterine bleeding
   Rate of oligiohydramnios
   Rate of IUGR




                          Doppler French Study Group
                          Br J Obstet Gynecol 1997, 104:419
                                                   Low-Risk


Methods
 Neonatal Assessment
   Peri-and neonatal death
   Rate of fetal distress
   APGAR scores
   Neonatal resuscitation
   Neonatal transfer
   Birthweight



                              Doppler French Study Group
                              Br J Obstet Gynecol 1997, 104:419
                               Low-Risk


Methods




          Doppler French Study Group
          Br J Obstet Gynecol 1997, 104:419
                                                      Low-Risk


Results
 Effects of Umbilical Artery Doppler
   No increase in antenatal
   hospitalizations
   No effect on the incidence of obstetrical
   complications
   Did not influence preterm delivery
   Did not influence mode of delivery




                                 Doppler French Study Group
                                 Br J Obstet Gynecol 1997, 104:419
                                                     Low-Risk


Results
 Effects of Umbilical Artery Doppler
   No   difference in fetal distress during
   labor
   THERE WERE THREE TIMES FEWER
   FETAL DEATHS IN THE DOPPLER
   GROUP
   (Larger study size would have resulted in
   statistical significance)


                                Doppler French Study Group
                                Br J Obstet Gynecol 1997, 104:419
                                                        Low-Risk


Conclusions
 Effects of Umbilical Artery Doppler
   No  benefit to umbilical artery in
   low-risk patients




                                   Doppler French Study Group
                                   Br J Obstet Gynecol 1997, 104:419
                                                       Low-Risk


Suggestions
 If Doppler is available, I would
 suggest using it for the
 following reasons:
       It may identify a fetus with
      IUGR who registers later and
      you are uncertain of the
      gestational age



                                  Doppler French Study Group
                                  Br J Obstet Gynecol 1997, 104:419
Suggestions
 Low-Risk Population
   May result in the discovery of high-
   risk patients who are unsuspected
   clinically
   May identify patients at risk for
   toxemia



                             Doppler French Study Group
                             Br J Obstet Gynecol 1997, 104:419
Part II: The Use of
  Uterine Artery
      Doppler
Review
Anatomy
   Blood supply provided
    by the ovarian and
    uterine arteries
   Uterine Arteries: main
    branches of the internal
    iliac arteries
   Uterine Arteries:
    Ascend through the
    lateral wall and
    anastomose with the
    ovarian arteries
Review
    Anatomy
   Arcuate Arteries: Run
    Circumferentially around
    the uterus
   Uterus: Blood supply to
    anterior and posterior
    walls provided by the
    Arcuate arteries
   Radial Arteries: Extend
    from the arcuate arteries
    and enter the
    endometrium
Review
Anatomy
    Spiral Arteries: 100
     connect the
     maternal circulation
     to the endometrium
    Responsible for a 10
     fold increase in
     blood flow
Review
Anatomy
Two    waves of trophoblastic invasion:
First trimester and second trimester

Conversion    of small muscular spiral
arteries into large vascular channels
transforms the uteroplacental
circulation into a low-resistance-to-flow
system
Review
Waveform

    Component 1:
     Pulsatile Waveform


    Component II:
     Steady Waveform
Review
Waveform

    Pulsatile Component:
     Formed by the interaction of
     an outgoing and reflected
     wave, which bounces back
     to the heart upon reaching
     the uteroplacental vascular
     bed
Review
Waveform Analysis

    Increased Resistance
        Decrease Mean Velocity
        Elevated PI
        Development of a notch
         in the early diastolic
         portion of the velocity
         waveforem caused by
         destructive interaction
         between outgoing and
         reflected waves
Review
Waveform Analysis

    Decrease Uterine Artery
     Radius
        Increase Mean Velocity
        Elevated PI and S/D
        NO DIASTOLIC NOTCH
Review
Waveform Analysis

    Increase Mean Arterial
     Pressure
        Elevation in mean
         velocity
        NO change in RI or S/D
        NO DIASTOLIC NOTCH
Review
Preeclampsia and Hypertension
   Abnormal decidual
    segments of the
    spiral arteries
   Minimal or no
    trophoblastic
    invasion beyond the
    decidual-myometrial
    junction
Review
Waveform Measurements


  Resistance Index of
  > 0.58 after 18
                        Systole
  weeks of gestation

                                  Diastole
  RI = (S-D)/S
Review
Waveform Measurements


  Diastolic Notch
  (irrespective of
       the RI)
                                             High-Risk


Studies
Prediction of Preeclampsia

    Arduini 1987
                       Total Patients: 563
    Jacobson 1990
    Montenegro 1992
                       Prevalence: 11%
    Bower 1993        Sensitivity: 81%
                       Specificity: 82%
                                          High-Risk


Studies
Prediction of IUGR


   Jacobson 1990    Total Patients: 93
                     Prevalence: 18%
                     Sensitivity: 71%
                     Specificity: -
                                         Low-Risk


Studies
Prediction of Preeclampsia

    Steel 1990
                       Total Patients: 6657
    Harrington 1992
    Bower 1993
                       Prevalence: 4.4%
    Valensise 1993    Sensitivity: 56%
    North 1994        Specificity: 72%
                                        Low-Risk


Studies
Prediction of IUGR

    Steel 1990
                      Total Patients: 4515
    Newnham 1990
    Uzan 1994
                      Prevalence: 7.7%
    Bower 1993       Sensitivity: 41%
    Valensise 1993   Specificity: 89%
    North 1994
              Preeclampsia              IUGR

            Total Patients: 563    Total Patients: 93
High-Risk   Prevalence: 11%        Prevalence: 18%
            Sensitivity: 81%       Sensitivity: 71%
            Specificity: 82%       Specificity: -

            Total Patients: 6657   Total Patients: 4515
Low-Risk
            Prevalence: 4.4%       Prevalence: 7.7%
            Sensitivity: 56%       Sensitivity: 41%
            Specificity: 72%       Specificity: 89%
Treatment
Aspirin

           Low-Dose Aspirin Can Be Used
               As A Form Of Therapy

          Rationale: Imbalance favoring the
          production of thromboxane A2 over
          prostacyclin is thought to play an
          important role in the pathogenesis of
          preeclampsia and somes caes of IUGR.
Treatment
Aspirin

                   How Does It Work?

          Rationale: Low-dose aspirin irreversibly
          inhibits almost all platelet cyclooxygenase
          activity, thereby blocking the production of
          thromboane A2, a potent vacoconstrictor
          and paltelet-aggregating agent.
 Treatment
Criteria For Treatment


         1. Persistence of a Diastolic Notch
         after 24 to 26 weeks of gestation.

         2. An RI greater than 0.58 after 24
         weeks.
 Treatment
Dosage of Aspirin


        50 to 150 mg/day beginning at 24
        weeks. Stuart Campbell has
        begun aspirin at 20 weeks when
        bilateral notching is present
                                                            High-Risk


Studies
Incidence of Preeclampsia: Aspirin vs Placebo

                      Total Patients Tx with Aspirin: 106
   MacParland 1990   Total Patients Tx with Placebo: 108
   Montenegro 1990   Preeclampsia Aspirin Group: 7%
                      Preeclampsia Control Group: 41%
   Uzan 1994         P < 0.00001
   Bower 1993        Relative Risk: 6 times greater for
                      the Placebo Group to develop
                      preeclampsia
                                                            High-Risk


Studies
Incidence of IUGR: Aspirin vs Placebo


   MacParland 1990   Total Patients Tx with Aspirin: 106
   Montenegro 1990   Total Patients Tx with Placebo: 108
                      IUGR Aspirin Group: 15%
   Uzan 1994
                      IUGR Control Group: 26%
   Bower 1993        P < 0.08
                                                      High-Risk


Studies
Elevated Maternal Serum Alpha-Fetoprotein

    Increased MSAFP is associated with an
    increased risk for perinatal death, preterm
    delivery, and IUGR.

    Patients with an increased MSAFP and an
    abnormal uterine artery Doppler velocimetry are
    at increased risk for adverse perinatal outcome
Studies
Elevated Maternal Serum Alpha-Fetoprotein
    Number of Patients: 98
    Criteria: Elevated MSAFP and abnormal uterine artery
    Doppler velocimetry after 24 weeks
    Findings:
    •14% perinatal death rate
    •25% delivered prematurily
    •20% had IUGR
    •Persistent notch after 24 weeks predicted 79% of perinatal
    deaths
                     (Aristidou A, Van Den Hof M, Campbell S, et al.
      Uterine artery Doppler in the investigation of pregnancies with raised maternal
              serum alpha-fetoprotein. Br J Obstet Gynaecol 1990; 97:431)
Studies
Preterm Labor

    Number of Patients: 92
    Criteria: Preterm labor and abnormal uterine artery
    Doppler velocimetry
    Findings:
    •Preterm Delivery: PPV 78.6%, NPV 69.2%
    •Abnormal perinatal outcome: PPV 64.3%, NPV 82.1%

     (Brar HS, Medearis AL, DeVore GR et al, Maternal and feal blood flow velocity
           waveforms in patient with preterm labor. Relationship to outcome.
                        Am J Obstet Gynecol 1989; 161:1519)
Conclusions
 Uterine Artery Doppler Velocimetry
     This screening test identifies
     patients at increased risk for
     adverse perinatal outcome
     This test should be done at 18
     to 22 weeks during the
     anatomical survey
     If abnormal at 24 weeks, low-
     dose aspirin should be initiated

				
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