Presentation on theme: "Doppler Ultrasonography in Obstetrical Practice China Medical University Hospital OBS & GYN department Chien Chung, Lee."— Presentation transcript:
Doppler Ultrasonography in Obstetrical Practice China Medical University Hospital OBS & GYN department Chien Chung, Lee
Conditions That Place Fetuses at Risk for Adverse Outcomes Maternal Chronic hypertension Collagen-vascular diseases Sickle cell anemia Current substance abuse Impaired renal function Asthma Pneumonia Significant cardiac disease Seizure disorders Diabetes Acute febrile illnesses Significant anemia (hematocrit <26% Fetal Intrauterine growth restriction Congenital anomalies Fetal cardiac arrhythmias Isoimmunization Hydrops fetalis Fetal infections such as parvovirus, coxsackievirus B, syphilis, toxoplasmosis Pregnancy-related Poorly controlled gestational diabetes Multiple gestations Pregnancy-induced hypertension Cholestasis of pregnancy Premature rupture of the membranes (preterm) Unexplained elevated maternal serum alpha-fetoprotein Polyhydramnios Oligohydramnios Placental abruption Abnormal placentation Postdates Unexplained stillbirth in a prior pregnancy
General Guidelines for Antepartum Testing IndicationInitiationFrequency Post-term pregnancy41 weeksTwice a week Preterm rupture of the membranesAt onsetDaily Oligohydramnios26 weeks or at onsetTwice a week Polyhydramnios32 weeksWeekly Class A1 DM (well-controlled, no complications)36 weeksWeekly Class A2 and B (well-controlled, no complications)32 weeksTwice a week Class A or B with poor control, Class C-R28 weeksWeekly Chronic or pregnancy-induced hypertension28 WeeksWeekly Steroid-dependent or poorly controlled asthma28 WeeksWeekly Collagen-vascular disease including antiphospholipid antibody syndrome 28 WeeksWeekly Impaired renal function28 weeksWeekly Uncontrolled thyroid disease32 weeksWeekly Maternal heart disease (NYHA class III or IV)28 weeksOnce a week Substance abuse32 weeksWeekly Prior stillbirthAt 2 weeks before prior fetal deathWeekly Multiple gestation32 weeksWeekly Fetal growth restriction26 weeks or at onsetTwice a week Decreased fetal movementAt time of complaintOnce Cholestasis32 weeksWeekly
Biophysical profile for fetal assessment in high risk pregnancies (Cochrane Methodology Review) Reviewers' conclusions: At present, there is not enough evidence from randomised trials to evaluate the use of biophysical profile as a test of fetal well- being in high risk pregnancies. Alfirevic Z, Neilson JP. In: The Cochrane Library, Issue 4, 2003.
Doppler ultrasound for fetal assessment in high risk pregnancies (Cochrane Methodology Review) Reviewers' conclusions: The use of Doppler ultrasound in high risk pregnancies appears to improve a number of obstetric care outcomes and appears promising in helping to reducing perinatal deaths. Neilson JP, Alfirevic Z.. In: The Cochrane Library, Issue 4, Neilson JP, Alfirevic Z.. In: The Cochrane Library, Issue 4, 2003.
Descriptive characteristics of randomized trials evaluating the use of Doppler ultrasonography in pregnancy included in overview Reference No. of participant Perinatal deaths (%) Type of Doppler ultrasonography used AEDV (%) Controls Prespecified primary end point with sample size calculations Trudinger et al., 1987, l2892.1Umbilical artery, CW 4 MHz?Gestational age at delivery McParland and Pearce, Umbilical and uterine arteries, PW15.1Death before discharge from hospital Tyrell et al., Umbilical and uterine arteries, CW, 4 MHz, 100 hZ 2.7No. of days in neonatal intensive care unit, frequency of low Apgar score Hofmeyr et al., Umbilical artery, CW, 4 MHz, 50 Hz filter?Not stated Newnham et al., Umbilical artery, CW, 280 Hz filter2.9Neonatal hospital stay Burke et al., Umbilical artery, CW, 4 MHz, 150 Hz filter?Not stated Almstrom et al., Umbilical artery, PW, 3 MHz, 100 Hz filter1.9Not stated Biljan et al., Umbilical artery, CW, 4 MHz, 100 Hz filter1.3No. of antenatal tests per patient, duration of antenatal stay Johnstone et al., Umbilical artery, CW, 4 MHz, Hz filter??Not stated Pattison et al., Umbilical artery, CW, 4 MHz, 100 Hz filter9.4Perinatal mortality Neales et al4675.3Umbilical artery, CW, 4 MHz6.4Not stated Nienhuis and Hoogland 150S3.4Umbilical artery, PW, 50 Hz filter?Not stated
Proportional effect of Doppler ultrasonography on number of dead babies (stillbirths and neonates) when used in high-risk pregnancies. Meta-analysis shows that clinical action guided by Doppler ultrasonography reduced the odds ratio of perinatal death by 38%
Effects of Doppler ultrasonography on perinatal outcomes in high-risk pregnancies. Post hoc analysis. The 16% reduction in the number of elective deliveries, 31% reduction in fetal distress in labor, and 87% reduction in hypoxic encephalopathy in the Doppler group reached statistical significance.
Conditions for Doppler ultrasound (1) Pregnancies complicated by IUGR (2) Pregnancies in which the fetus is at risk for anemia (3) Multiple gestations (4) Pregnancies treated with prostaglandin inhibitors to monitor the ductus arteriosus (5) Fetal echocardiograms
Doppler Flow Velocity in the First Trimester Comparison of endometrial thickness, RI, & gestational age between groups Retained tissue Not retained tissue P Gestational age 10.0(3.3)7.6(2.0)0.001 Endometrial thickness(mm) 19.5(1.8)10.2(7.0)0.001 RI0.38(0.16)0.59(0.12)0.001 Alcazar JL, Ortiz CA. Eur J Obstet Gynecol Reprod Biol Apr 10;102(1):83-7.
(A)Normal uterine artery at 12 weeks shows relatively high resistance, absent notching. (B)Normal midtrimester uterine artery, increased diastolic flow. (C) Normal third trimester uterine artery, very low resistance. (D)High resistance with persistent notching may be normal in first trimester, not in this 24-week gestation. (E)Very high resistance, marked notching, absent diastolic velocities in a woman with pre-eclampsia, and severe intrauterine growth restriction (IUGR) at 28 weeks.
(A)Normal umbilical artery at 18 weeks shows relatively high resistance, but consistent diastolic flow. (B)Normal umbilical artery at 36 weeks, low resistance, generous diastolic flow. (C)High resistance, diastolic velocity low. (D)Absent end-diastolic velocity (AEDV). (E)Reversed diastolic velocity (REDV) in severe intrauterine growth restriction (IUGR). Doppler Flow Velocity in Umbilical Artery
Madazli R, Uludag S, Ocak V. Acta Obstet Gynecol Scand 2001; 80:702 Fetuses with absent end-diastolic velocity of the umbilical artery all died in utero within 3 weeks (median 7 days).
FACTORS AFFECTING UMBILICAL ARTERY DOPPLER FLOW VELOCITY WAVEFORMS Gestational ageEDFV ratio increases with advancing gestational age Fetal heart rateEDFV decreases with decreasing fetal heart rate Fetal breathing movementsIncreases variability in the measurements Site of measurementEDFV is higher near the placental insertion than near the umbilical cord insertion into the fetal abdomen Equipment used : continuous Doppler versus pulsed Doppler Continuous Doppler is more a “blind technique” compared with pulsed Duplex Doppler, allowing 2D real time ultrasound User experienceReliability increases with increasing experience Radius of the umbilical arteryDecreasing radius (vasoconstriction) increases EDFV Impedance to pulsatile flow propagationIncreasing vascular impedance increases EDFV Downstream vascular resistance within the microcirculation Increasing vascular resistance decreases EDFV Angle of the fetal Doppler insonationBest if less than 45˚; <15˚ for MCA absolute peak systolic flow velocity
Diagnostic efficacy of umbilical arterial Doppler in IUGR Author DI Prevalence Sensitivity Specificity PPV Fleischer S/D> Aruidini PI>1SD Berkowitz S/D> Divon S/D> Gaziano S/D> Ott S/D> Maulik S/D> Lowery S/D> Lee S/D>
Middle cerebral artery Doppler waveforms Normal flow of the Middle Cerebral Artery in 1º trimester Normal flow of the Middle Cerebral Artery in 2º and 3º trimester
Middle cerebral artery Doppler waveforms (A) Normal middle cerebral artery (MCA) at term - normal peak systolic velocity (58 cm/s), high resistance, low end-diastolic velocity. (B) ‘Brain sparing’ MCA - lower peak, much higher diastolic velocity suggests cerebrovasodilation. (C) Anemic fetus with retained high resistance, elevated peak systolic velocity (77 cm/s).
Doppler Flow Velocity in Ductus venosus
The upper panel represents the venous waveform, correlated with the EKG in the lower panel. A = atrial systole, S = ventricular systole, D = early ventricular diastole. The colored portions of the waveform represent the Tamx for atrial systole (gold), ventricular systole (red), and early ventricular diastole (blue). The yellow arrows represent the measurement of the peak velocity for ventricular systole and early ventricular diastole. The black arrow represents the peak velocity for atrial systole.
(A) Ductus venosus (DV) Doppler waveforms at 12 weeks gestation. (B) At 12 weeks gestation, an abnormal a- wave (a), correctly predicted anomalous pulmonary and systemic venous return, proven by fetal echocardiography at 24 weeks. (C) DV at 26 weeks, with 4-phase waveform. (1) atrial contraction (2) ventricular systole, (3) return (ascent) of the annulus (called the y- descent of the DV waveform), & (4) diastole. (D) Normal waveform from the middle hepatic vein which, is only a few millimeters from the DV.
Doppler Flow Velocity in IUGR
Progressive changes in Doppler parameters in IUGR fetuses delivered for an abnormal Biophysical Profile Score.
Hemodynamic changes occurring in fetal arterial vessels during hypoxemia and acidemia induced by uteroplacental insufficiency Vessel Impedance to flow Impedance to flow Descending aorta Increased Renal artery Increased Femoral artery Increased Peripheral pulmonary artery Increased Mesenteric arteries Increased Cerebral arteries Decreased Adrenal arteries Decreased Splenic arteries Decreased Coronary arteries Decreased
Fetal Systemic Vascular Responses in IUGRA/REDV, absent or reversed end- diastolic velocities Fetal Systemic Vascular Responses in IUGRA/REDV, absent or reversed end- diastolic velocities HARMAN: Clin Obstet Gynecol, 46(4).December
Aortic isthmus blood velocity waveform a) normal blood flow pattern in an uncomplicated pregnancy In the sagittal view of the fetus, the aortic arch and the location of the aortic isthmus (white triangle) are shown. b) antegrade net blood flow (antegrade/retrograde ratio of 2.0) c) retrograde net blood flow with a corresponding value of 0.54 in pregnancies complicated by placental insufficiency.
Coronary artery blood velocity waveform of a growth- restricted 32 week fetus (heart sparing effect).
Alfred Abuhamad et al. Contemporary Ob/Gyn May 1, 2003;48:56-73
Evaluation of fetal intrapartum hypoxia by middle cerebral & umbilical artery Doppler velocimetry with simultaneous cardiotocography & pulse oximetry During active labor the fetus maintains oxygen supply to the brain by redistributing blood flow. In cases of hypoxia this is feasible for only 2 min. During active labor the fetus maintains oxygen supply to the brain by redistributing blood flow. In cases of hypoxia this is feasible for only 2 min. Siristatidis C, Salamalekis E, Kassanos D, Loghis C, Creatsas G Arch Gynecol Obstet Nov 5
Spectral Doppler waveform of an A-A anastomosis with characteristic bidirectional, pulsatile flow.
Which Doppler Tests Should be Performed? Uterine arteries depict maternal vascular effects of the invading placenta 2. Umbilical artery Doppler reflects downstream placental vascular resistance 3. Middle cerebral artery changes begin when the redistribution of cardiac output reflects rising placental resistance 4. precordial veins illustrate fetal cardiac function
DIFFERENTIAL DIAGNOSIS OF OLIGOHYDRAMNIOS PPROM --- normal renal vessels, normal umbilical flow & normal --- normal renal vessels, normal umbilical flow & normal filling of the bladder. filling of the bladder. Bilateral renal agenesis or dysplasia --- umbilical artery Doppler is normal, but no renal vessels & --- umbilical artery Doppler is normal, but no renal vessels & no bladder filling no bladder filling Severe hypoxia with IUGR --- fetal measurements are small for gestation, fetal heart --- fetal measurements are small for gestation, fetal heart looks dilated & the bowel is echogenic. Doppler looks dilated & the bowel is echogenic. Doppler demonstrates the presence of two renal arteries and absent demonstrates the presence of two renal arteries and absent or reversed end-diastolic frequencies in the umbilical arteries or reversed end-diastolic frequencies in the umbilical arteries
Deficient placentation defined by notched uterine arteries Increased umbilical artery resistance with progression to AEDV/REDV Declining CPR, brain-sparing MCA As the arteriovenous ratio decline, ductus venosus abnormality begins Abnormal biophysical variables emerge Oligohydramnios and abnormal (non-reactive) fetal heart rate tracing Loss of fetal breathing movements, body movements and fetal tone
THE USE OF FETAL DOPPLER IN OBSTETRICS Society of Obstetricians and Gynaecologists of Canada. No. 130, July Umbilical artery Doppler should be available for assessment of the fetal-placental circulation in pregnant women with suspected severe placental insufficiency. (I-A) 2. Depending on other clinical factors, reduced, absent, or reversed umbilical artery end-diastolic flow is an indication for enhanced fetal surveillance or delivery. If delivery is delayed to enhance fetal lung maturity with maternal administration of glucocorticoid, intensive fetal surveillance until delivery is suggested for those fetuses with reversed end-diastolic flow. (II-1B) 3. Umbilical artery Doppler should not be used as a screening tool in healthy pregnancies, as it has not been shown to be of value in this group. (I-A) 4. Umbilical venous double pulsations, in the presence of abnormal umbilical artery Doppler waveforms, necessitate a detailed assessment of fetal health status. (II-3B) 5. Measurement of the fetal middle cerebral artery Doppler peak systolic flow velocity is a predictor of moderate or severe fetal anemia and can be used to avoid unnecessary invasive procedures in pregnancies complicated with red blood cell isoimmunization. (II-1A) 6. Since inaccurate information concerning fetal Doppler studies could lead to inappropriate clinical decisions, it is imperative that measurements be undertaken and interpreted by expert operators who are knowledgeable about the significance of Doppler changes and who practise appropriate techniques. (II-1A)
Conclusion No single diagnostic modality can provide information complete enough to adequately address the complex nature of IUGR and its interacting fetal compensations and compromises No single diagnostic modality can provide information complete enough to adequately address the complex nature of IUGR and its interacting fetal compensations and compromises Management decisions based on Doppler data are gestational age dependent Management decisions based on Doppler data are gestational age dependent