this is what we presented at AICOG 2012 varanasi .............USG A WATCH DOG FOR PREGNANCY...................please let me know what more any one wants to see, i can keep uploading my presentations.....
ULTRASOUND AS A WATCH DOG FOR PREGNANCY narendra malhotra jaideep malhotra neharika malhotra www.malhotrahospitals.com
http://en.wikipedia.org/wiki/watch dog • Watchdog may refer to: Dog Guard dog, a dog that barks to alert its owners of an intruders presence WIKTIONARY Noun watchdog (plural watchdogs) a guard dog a person or organization that monitors and publicizes the behavior of others (individuals, corporations, governments) to discover undesirable activity.
PREGNANCY IS THE OWNER AND THE “GREAT OBSTETRICAL SYNDROME” IS THE INTRUDER AND ULTRASOUND THE WATCH DOGAND WE OBSTETRICIANS ARE THE DOG TRAINERSso it becomes a very doggy-bitchy story and lecture
Obstetrical Disease • Preterm labor • Preterm Rupture of membranes • Pre-eclampsia • SGA/IUGR • Fetal DeathIn addition to the above ;first trimester preg failure,early anomalies ,late anomalies
The History of Obstetrics• A search for a single test to predict each obstetrical disorder has failed.• The discovery of an effective treatment and preventive strategy has not been successful.
Diagnostic toolsOnly one singlediagnostic tool hasproven to be the onlytool which can predictproblems and watch thepregnancy like a watchdog and indicate theintruders of the “greatobstetrical syndrome”
Treatments available today Disease TreatmentPreterm labor Tocolysis ExpectantPreterm PROM management AntihypertensivePre-eclampsia agents IUGR DeliveryFAILED PREGNANCY AND LETHAL ANOMALIES……TERMINATION
“Great Obstetrical Syndromes”• Multiple etiologies• Long pre-clinical phase• Fetal diseases• Clinical manifestations are adaptive• Symptomatic treatment is ineffective• Genetic/environmental factors
Small for Gestational Age Environmental Infection/ Inflammation Genetic Endocrine MaternalNutritionalPlacental Unknown
OBSTETRICAL ULTRASOUND HELPSPICK UP ALL THESE PROBLEMS EARLY• EARLY SCAN TO DETECT PREGNANCY AND RULE OUT ECTOPIC• FETAL CARDIAC ACTIVITY/VIABILITY SCAN• CHORIONICITY IN MULTIPLE GESTATION• 11-14 WEEKS GENETIC SCAN• 20 WEEKS ANOMALY SCAN• 24 WEEKS DOPPLER• THIRD TRIMESTER GROWTH AND LIQUOR
Definite signs of Early Pregnancy Failure• Absence of cardiac activity in an embryo -Embryonic demise• Absence of yolk sac/embryo in a large GS -Blighted ovum FAILED PREGNANCY
Definite signs of Early Pregnancy FailureWhat is the descriminatory size for safe diagnosis? Mean Sac diameter CRL
GUIDELINES FOR DIAGNOSIS OF EARLY PREGNANCY FAILURE Society of American CollegeRoyal College of Obstetricians and of RadiologistsObstetricians Gynaecologists of (ACR) 2000and Canada (SOGC) 2005Gynaecologists • CRL > 5mm with no • CRL > 5mm with no visible visible cardiac activity(RCOG) 2006 cardiac activity, >9mm(TAS) • MSD > 16mm without a• CRL ≥ 6mm with no • MSD > 8mm without a visible visible embryo or yolk sacvisible cardiac activity yolk sac, 20mm (TAS)• MSD ≥ 20mm without AIUM, 2007 • MSD > 16mm without a • CRL > 5mm (TVS) with noa visible embryo or visible embryo, (25mm (TAS)yolk sac visible cardiac activity LEVEL 11-2 a
GUIDELINES FOR DIAGNOSIS OF EARLY PREGNANCY FAILURE Australian Society Practice in theHongkong College Philippinesof Obstetricians for Ulltrasound inand Gynaecologists Medicine (ASUM)(HKCOG) 2004 • CRL > 5mm with no• CRL > 5mm (TVS), >9mm • CRL > 6mm with no visible cardiac activity(TAS) with no visible visible cardiac activitycardiac activity • MSD > 18mm without a • MSD > 20mm without a visible embryo or yolk sac• MSD ≥ 20mm without a visible embryo or yolk sac OB-GYN USG for practicingvisible embryo or yolk sac Clinician 2nd Ed FOGSI GUIDELINES A FEW YEARS BACK MSD >20without YS/E :CRL >6mm without cardiac activity IFUMB/ICMU and ICOG
RECOMMENDATIONSEmpty GS = an MSD of 25 mm with out yolk sac or embryoEmbryonic demise= A CRL of 7mm with no cardiac activityWait for 7-10 days before a repeat scan if results are below the descriminatory level.
Down syndrome screening• NT (11-13+6wk), PAPP-A, beta-hCG• Best at 12 wk for anomaly as well• One-stop• 90% sensitivity at 5% FP rate• Addition of Doppler assessment of blood flow in the ductus venosus and across the tricuspid valve together with above can identify more than 95% of all major aneuploidies for a FP rate of less than 3%.
Why 13+6 wk?• To provide women with affected fetuses the option of first- rather than second-trimester termination,• The incidence of abnormal accumulation of nuchal fluid in chromosomally abnormal fetuses decreases after 13 weeks• The success rate for taking a measurement decreases after 13 weeks because the fetus becomes vertical, making it more difficult to obtain the appropriate image.
Other aneuploidies NT Beta-hCG PAPP-ATrisomy 21 increased increased decreasedTrisomy 18 increased decreased decreasedTrisomy 13 increased decreased decreasedTurner syndrome increased normal decreasedTripoloidy (paternal) increased decreased mildy
Cardiac defect• Major cardiac defect in 7.6% of chromosomally normal fetuses with NT>=3.5mm• Indication for fetal echocardiography• Detailed cardiac scan at 14 wk
OTHER MARKERS BY USG ICT DV NBCORD DIAMETER WIDE ILIAC BONES FACIAL ANGLE
ULTRASOUND IS A GOOD WATCH DOG FOR FIRST TRIMESTER PREGNANCY PROBLEM PREDICTION
The mid-trimester fetal ultrasound scan Who should have one: everyone ……all pregnant women should be offered an ultrasound scan for the detection of fetal anomalies and pregnancy complications…….if problems in unselected low risk have also to be picked up….(no clear evidence on usefulness)
The mid-trimester fetal ultrasound scan When should the scan be performed?• “18-22 weeks”• Earlier scans date better• Earlier scans require equipment, expertise and time• Later scans see better• Later scans see more• Local legislation
The mid-trimester fetal ultrasound scan And now coming to the core stuff! •Fetal biometry and well being •Anatomical survey
The mid-trimester fetal ultrasound scan Fetal biometry and well being • Fetal biometry • Amniotic fluid assessment • Fetal movement • Doppler ultrasonography • Multiple gestation
Fetal biometry Parameters• Standardised manner and strict quality criteria• Audit of results• Still images to document the measurements
Fetal well being Estimated fetal weight• The degree of deviation from normal at this early stage of pregnancy that would justify action (e.g. follow-up scan to assess fetal growth or fetal chromosomal analysis) has not been firmly established• if gestational age is determined at an earlier scan, EFW can be compared to dedicated normal, preferably local, reference ranges for this parameter
Fetal well being Amniotic fluid assessment• Amniotic fluid volume can be estimated subjectively or by using sonographic measurements• Subjective estimation is not inferior to the quantitative measurement techniques (e.g. deepest pocket, amniotic fluid index) when 270 250 performed by experienced examinersAmniotic Fluid Index 230 210 190 170 150 • Patients with deviations from normal 130 110 should have more detailed anatomical 90 70 evaluation and clinical follow-up 16 18 20 22 24 26 28 30 32 34 36 38 40 Week
Fetal well being Fetal movement• There are no specific movement patterns at this stage of pregnancy• Temporary absence or reduction of fetal movements during the scan should not be considered as a risk• Abnormal positioning or unusually restricted or persistently absent fetal movements may suggest abnormal fetal conditions such as arthrogryposis
Fetal well being Fetal movement• The biophysical profile is not considered part of a routine mid-trimester scan!• Fetal brain is not yet mature enough to control sympathetic and parasympathetic of fetal heart!
Fetal well being Doppler ultrasonography• The application of Doppler techniques is not currently recommended as part of the routine second-trimester ultrasound examination• There is insufficient evidence to support universal use of uterine or umbilical artery Doppler evaluation for the screening of low-risk pregnancies
Fetal well being Multiple gestations• visualization of the placental cord insertion• distinguishing features (gender, unique markers, position in uterus)• determination of chorionicity is sometimes feasible in the second trimester if there are clearly two separate placental masses and discordant genders. Chorionicity is much better evaluated before 14–15 weeks (lambda sign or T- sign).
The anatomical survey in second trimester At a glanceHead Intact cranium Abdomen Cavum septi pellucidi Stomach in normal position Midline falx Bowel not dilated Thalami Both kidneys present Cerebral ventricles Cord insertion site Cerebellum Skeletal Cisterna magna No spinal defects or masses (transverse andFace Both orbits present sagittal) Median facial profile Arms and hands present, normal Mouth present relationships Upper lip intact Legs and feet present, normal relationshipsNeck Absence of masses (e.g. cystic hygroma) Placenta PositionChest/Heart No masses present Normal shape/size of chest and lungs Accessory lobe Heart activity present Umbilical cord Four-chamber view of heart in normal Three-vessel cordposition Genitalia Aortic and pulmonary outflow tracts Male or female No evidence of diaphragmatic hernia
Placenta Guidelines for maturity and position + + + + + +• Women with a history of uterine surgery and low anterior placenta or placenta previa are at risk for placental attachment disorders. In these cases, the placenta should be examined for findings of accreta, the most sensitive of which are the presence of multiple irregular placental lacunae that show arterial or mixed flow• Abnormal appearance of the uterine wall–bladder wall interface is quite specific for accreta, but is seen in few cases. Loss of the echolucent space between an anterior placenta and the uterine wall is neither a sensitive nor a specific marker for placenta accreta
Maternal anatomy Guidelines• Currently, there is sufficient evidence to recommend routine cervical length measurements with a transvaginal scan at the mid trimester even in an unselected population• Uterine fibroids and adnexal masses should be documented
THIRD TRIMESTER SCAN Great obstetrical syndrome• Preterm labor• Preterm Rupture of membranes• Pre-eclampsia• SGA/IUGR• Fetal Death Fetal growth restriction
FGR may be Symmetrical Asymmetrical and bodyFetal brain (BPD & HC) Fetal brain (BPD & HC) and(AC) and long bones are long bones are large whenproportionately small. compared to the AC (liver).may occur when the fetus may occur when the fetusexperiences a problem during experiences a problem duringearly development. later developmentChromosomal malformationConstituently Small (Small Hypoxemic hypoxiaMother Small Baby ) utero placental insufficiency
Accurate fetal biometry to measure the size of fetus – AC & EFWPredictive tools rule of 2
Accurate fetal biometry to measure the size of fetus – AC & EFW Accurate measurement of fetal growth - IndianPredictive tools & customized rule of 2 fetal growth charts
Accurate fetal biometry to measure the size of fetus – AC & EFW Accurate measurement of fetal growth - IndianPredictive tools rule & customized fetal of 2 growth charts Accurate knowledge of fetal physiology and intrauterine environment - fetal Doppler study & AFI ACHARYA DR.PRASHANT
• Biometric tests (tests to measure size) • Biometric tests are designed to predict size and growth AC, EFW
USG TOOLS – HOW EFFECTIVE ?• Ratio measures, such as head to abdominal circumference (HC/AC) and femoral length to abdominal circumference (FL/AC) ratios are poorer than AC or EFW alone in predicting IUGR
Ask for serial measurements and plot the findings in growth chart – not single USG reading2/3/2012 DR.PRASHANT ACHARYA 47
PROPOSED INDIAN CUSTOMISED GROWTH CHART• The term 40 weeks birth • The term 40 weeks birth weight of fetus is 3051 for weight of fetus is 3455 for normal primi patient normal primi patient having average weight 52 having average weight 64 Kgs & average height of Kgs & average height of 152 cms 163 cms
Role of Doppler study in FGR• In diagnosing fetal hypoxia by detecting redistribution of fetal blood flow• Helps in deciding the Timing of Doppler detects flow of RBCs in any delivery vessel - Quantity and speed• Measuring AFI
Uterine artery Doppler waveform• Impaired placentation• P I P I P (OBS SYNDROME)50-67% Positive predictive value>95 % negative predictive value
Impaired placentationUterine artery Doppler Good diastolic flow High resistance , persistence of diastolic notching and even absent end systolic forward flow can persist through out pregnancy if PLACENTATION IS INADEQUATE In 50-67 % is associated Early diastolic notch Poor diastolic with complication of flow P I P I P &PPIHDR.PRASHANT ACHARYA 2/3/2012 52
Prediction & Prevention ofFGR by UTERINE ARTERY DOPPLER P I P I P GREAT OBSTETRICAL SYNDROME Preeclampsia IUD Prematurity IUGR Placental abruption
UMBILICAL ARTERY FLOWcharacteristic saw-tooth appearance of arterial flow inone direction and continuous umbilical venous blood flowin the other. 54
Absent / Reversed end diastolic volume (AEDV/REDV)• AEDV/REDV + PREMATURITY = high chances of HMD• neonatal complications are Asphyxia ,ICH are increased 2/3/2012 DR.PRASHANT ACHARYA
When Umbilical artery Doppler parameters are alteredMulti vessel Doppler Hypoxia andexamination (MCA and reDV) distributationBio Physical Profile Score CNS
Umbilical artery Doppler• When end diastolic flow is present , delay delivery until at least 35 weeks, provided other surveillance findings are normal.
MCA abnormality expressed by the compromised fetusBrain sparing effect – Fetal anemiaCerebral perfusionincreased ( RI & PIdecreased) MCA supplies blood to Brain - the most important organ of body- MCA PSV evaluates speed of fetal RBCs flow which has DIRECT application in FETAL ANEMIA
Middle cerebral artery An early stage in fetal adaptation to hypoxemia - central redistribution of blood flow ( brain-sparing reflex)increased blood flow to protect the brain, heart, and adrenalsreduced flow to the peripheral and placental circulations
• The aortic isthmus PI is increased and absolute velocities (especially the TAMXV) are reduced in intrauterine growth-restricted fetusesAortic isthmus blood flow velocimetry provides important information on fetal cardiovascularfunction, i.e. individual performance of ventricles, relative changes in upper (including brain)and lower (including placenta) body resistances and fetal oxygenation, and has the potentialto become a valuable clinical tool for fetal evaluation
FETAL DECENDING AORTA• it is important to be aware of the fact that the brief reversal of flow during end-systole, which is a normal finding in the third trimester, can give falsely high PI values
Ductus venosus (DV) Final verdict• Sensitive to fetal oxygenation status• Dilates as fetal hypoxia worsens• In severe hypoxia –reversal of (a) wave• Immediate delivery of Fetus- in abnormal DV flow
• Reflects VOLUME MANAGEMENT by RIGHT atrium and is responsive to fetal oxygenation • Dilates as fetal hypoxia worsens • In severe hypoxia –reversal of (a) wave ,due to atrial contraction s/o cardiac failure and decompansation due to increase in severe after load • Needs immediate delivery of Fetus2/3/2012 DR.PRASHANT ACHARYA 66
Amniotic Fluid Index• Reduction in AFI is Supporting evidence of a hostile intrauterine environment• Amniotic fluid volume monitoring is very helpful in monitoring the physiological status of the fetus rather than the anatomical growth.
BPPS or Modified BPPS ??• VAST• AFI• Instant, Easy and cost effective• Helps in delivering the fetus at optimal gestational age
Take Home Message• Worldwide, it is likely that much of the ultrasonography currently performed is carried out by individuals with little or no formal training(hence misinterpretations)• Performed with proper guidelines ROUTINE USG IN PREGNANCY can predict many problems and be a good watch dog for fetal and maternal wellbeing