Doppler - Doppler of the Uterine And Umbilical Arteries:...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 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: Observational Association between reduced endAssociation diastolic umbilical artery velocities and diastolic increased vascular resistance in the fetoplacental circulation fetoplacental Historical Perspective Observational Studies: Observational Complications of pregnancy associated with placental pathologic mechanisms with Adverse pregnancy outcome including perinatal death perinatal Historical Perspective Other Doppler Studies: Other Uterine arteries Uterine Middle Cerebral arteries Middle Venous system Venous Historical Perspective Benefit of Umbilical Artery Evaluation Benefit Less experienced operators can achieve highly reproducible results with simple, inexpensive continuous-wave equipment equipment Historical Perspective Problem With Observational Studies Problem Observations are often rushed into clinical practice only to find later that they are either ineffective or even harmful harmful Historical Perspective Randomized Controlled Trials Randomized “Gold Standard” for evaluating the Gold effectiveness of clinical investigations in the human population the “Meta Analysis” combines the results Meta from smaller trials of similar structure and purpose. and Historical Perspective Randomized Controlled Studies Randomized 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 of 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 Studies s s s s s s Trudinger et al 1987 McPharland et al 1988 Hofmeyr et al 1991 Newham et al 1991 Burke et al 1992 Almstrom et al 1992 s s s s s Biljan et al 1992 Johnstone et al 1993 Pattison et al 1994 Neales et al Neales (Unpublished) (Unpublished) Nienhuis (Unpublished) Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis Number Evaluated Number 7,474 Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis Absent End-Diastolic End-Diastolic Flow Flow 5.6% Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis: Results Perinatal Deaths Perinatal Clinical action guided by Doppler ultrasonography reduced the odds of perinatal death by 38%, with a 95% confidence interval of 15% to 55% confidence 10 of 12 studies demonstrated a reduction in death compared to controls reduction Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis: Results Antenatal Care and Labor Antenatal Reduction in antenatal admissions Reduction Reduction in inductions of labor Reduction Reduction of cesarean section for fetal distress during labor distress Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis: Results Neonatal Outcome Neonatal No effect on perinatal morbidity No No difference in birth weight No Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis: Results Other Outcomes Other Reduction of 16% in the number of elective deliveries elective Reduction of 31% of fetal distress during labor during Reduction of 87% of hypoxic encephalopathy encephalopathy Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, High-Risk Meta-Analysis: Conclusions Should additional studies be Should ethically done in light of the current results? current Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, 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. increases Alfirevic Z and Neilson JP Am J Obstet Gynecol 1995, 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 third 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 population 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: Women Medical history of hypertension Medical Medical history of diabetes Medical Obstetric history of fetal death Obstetric History of IUGR History Women who had undergone umbilical artery Doppler before 28 weeks artery Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Methods Study Design: Study Time of the Study: 1988-1990 Time 20 Antenatal Clinics throughout France 20 Control group: No Doppler studies Control Doppler group: Results of Doppler conveyed to physicians conveyed Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Methods Assessment of Pregnancy Care Assessment Number of antenatal visits Number Days of antenatal hospitalization Days Cardiotocography measurements Cardiotocography Rate of pregnancy induced hypertension hypertension Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Methods Assessment of Pregnancy Care Assessment Rate of pre-eclampsia Rate Rate of uterine bleeding Rate Rate of oligiohydramnios Rate Rate of IUGR Rate Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Methods Neonatal Assessment Neonatal Peri- and neonatal death PeriRate of fetal distress Rate APGAR scores APGAR Neonatal resuscitation Neonatal Neonatal transfer Neonatal Birthweight Birthweight Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Methods 2 0 C e n te rs 4 1 8 7 In c lu s io n s R o u tin e D o p p le r N u m b e r L o s t:1 4 0 N u m b e r S t u d ie d : 1 9 5 0 N o R o u tin e D o p p le r N u m b e r L o s t: 1 4 0 N u m b e r S t u d ie d : 1 9 4 8 Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Results Effects of Umbilical Artery Doppler Effects No increase in antenatal hospitalizations hospitalizations No effect on the incidence of obstetrical complications complications Did not influence preterm delivery Did Did not influence mode of delivery Did Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Results Effects of Umbilical Artery Doppler Effects No difference in fetal distress during labor labor THERE WERE THREE TIMES FEWER FETAL DEATHS IN THE DOPPLER GROUP (Larger study size would have resulted in statistical significance) statistical Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Low-Risk Conclusions Effects of Umbilical Artery Doppler Effects No benefit to umbilical artery in low-risk patients low-risk 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: following It may identify a fetus with IUGR who registers later and you are uncertain of the gestational age gestational Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Suggestions Low-Risk Population Low-Risk May result in the discovery of highMay risk patients who are unsuspected risk clinically clinically May identify patients at risk for toxemia toxemia Doppler French Study Group Br J Obstet Gynecol 1997, 104:419 Part II: The Use of Uterine Artery Doppler Review Anatomy s s s Blood supply provided Blood by the ovarian and uterine arteries uterine Uterine Arteries: main Uterine branches of the internal iliac arteries iliac Uterine Arteries: Uterine Ascend through the lateral wall and anastomose with the ovarian arteries ovarian Review Anatomy s s s Arcuate Arteries: Run Arcuate Circumferentially around the uterus Uterus: Blood supply to Uterus: anterior and posterior walls provided by the Arcuate arteries Arcuate Radial Arteries: Extend Radial from the arcuate arteries and enter the endometrium endometrium Review Anatomy s s Spiral Arteries: 100 Spiral connect the maternal circulation to the endometrium to Responsible for a 10 Responsible fold increase in blood flow blood Review Anatomy sTwo Two waves of trophoblastic invasion: First trimester and second trimester First sConversion Conversion of small muscular spiral arteries into large vascular channels transforms the uteroplacental circulation into a low-resistance-to-flow system system Review Waveform s Component 1: Component 1: Pulsatile Waveform Pulsatile Waveform s Component II:: Component II Steady Waveform Steady Waveform Review Waveform s Pulsatile Component: Formed by the interaction of an outgoing and reflected wave, which bounces back to the heart upon reaching the uteroplacental vascular bed bed Review Waveform Analysis s Increased Resistance s s s Decrease Mean Velocity Elevated PI Development of a notch Development in the early diastolic portion of the velocity waveforem caused by destructive interaction between outgoing and reflected waves reflected Review Waveform Analysis s Decrease Uterine Artery Decrease Radius Radius s s s Increase Mean Velocity Elevated PI and S/D NO DIASTOLIC NOTCH Review Waveform Analysis s Increase Mean Arterial Increase Pressure Pressure s s s Elevation in mean Elevation velocity velocity NO change in RI or S/D NO DIASTOLIC NOTCH Review Preeclampsia and Hypertension s s Abnormal decidual Abnormal segments of the spiral arteries spiral Minimal or no Minimal trophoblastic invasion beyond the decidual-myometrial junction Review Waveform Measurements Waveform Resistance Index of > 0.58 after 18 weeks of gestation RI = (S-D)/S Systole Diastole Review Waveform Measurements Waveform Diastolic Notch (irrespective of the RI) High-Risk Studies Prediction of Preeclampsia s s s s Arduini 1987 Jacobson 1990 Montenegro 1992 Bower 1993 Total Patients: 563 Prevalence: 11% Sensitivity: 81% Specificity: 82% High-Risk Studies Prediction of IUGR s Jacobson 1990 Total Patients: 93 Prevalence: 18% Sensitivity: 71% Specificity: - Low-Risk Studies Prediction of Preeclampsia s s s s s Steel 1990 Harrington 1992 Bower 1993 Valensise 1993 North 1994 Total Patients: 6657 Prevalence: 4.4% Sensitivity: 56% Specificity: 72% Low-Risk Studies Prediction of IUGR s s s s s s Steel 1990 Newnham 1990 Uzan 1994 Bower 1993 Valensise 1993 North 1994 Total Patients: 4515 Prevalence: 7.7% Sensitivity: 41% Specificity: 89% Preeclampsia High-Risk Low-Risk IUGR Total Patients: 563 Prevalence: 11% Sensitivity: 81% Specificity: 82% Total Patients: 93 Prevalence: 18% Sensitivity: 71% Specificity: - Total Patients: 6657 Prevalence: 4.4% Sensitivity: 56% Specificity: 72% Total Patients: 4515 Prevalence: 7.7% Sensitivity: 41% Specificity: 89% Treatment Aspirin Low-Dose Aspirin Can Be Used Low-Dose As A Form Of Therapy As Rationale: Imbalance favoring the production of thromboxane A2 over production prostacyclin is thought to play an important role in the pathogenesis of preeclampsia and somes caes of IUGR. preeclampsia 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 the potent vacoconstrictor and palteletpotent aggregating agent. Treatment Criteria For Treatment 1. Persistence of a Diastolic Notch 1. after 24 to 26 weeks of gestation. after 2. An RI greater than 0.58 after 24 2. weeks. Treatment Dosage of Aspirin 50 to 150 mg/day beginning at 24 50 weeks. Stuart Campbell has begun aspirin at 20 weeks when bilateral notching is present bilateral High-Risk Studies Incidence of Preeclampsia: Aspirin vs Placebo s s s s MacParland 1990 Montenegro 1990 Uzan 1994 Bower 1993 Total Patients Tx with Aspirin: 106 Total Patients Tx with Placebo: 108 Preeclampsia Aspirin Group: 7% Preeclampsia Control Group: 41% P < 0.00001 Relative Risk: 6 times greater for the Placebo Group to develop preeclampsia High-Risk Studies Incidence of IUGR: Aspirin vs Placebo s s s s MacParland 1990 Montenegro 1990 Uzan 1994 Bower 1993 Total Patients Tx with Aspirin: 106 Total Patients Tx with Placebo: 108 IUGR Aspirin Group: 15% IUGR Control Group: 26% 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 Velocimetry This screening test identifies patients at increased risk for adverse perinatal outcome adverse This test should be done at 18 to 22 weeks during the anatomical survey anatomical If abnormal at 24 weeks, lowIf dose aspirin should be initiated ...
View Full Document

Ask a homework question - tutors are online