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OB GYNE ULTRASOUND concepts & its clinical correlation. Jan Charmaine Almonte-Saret M.D., FPOGS, FPSUOG. FIRST TRIMESTER ULTRASOUND. equal or less than 13 weeks Indications and advantages: confirmation of intrauterine pregnancy/ early pregnancy failure best estimation of G.A.
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OB GYNE ULTRASOUND concepts & its clinical correlation Jan Charmaine Almonte-Saret M.D., FPOGS, FPSUOG
FIRST TRIMESTER ULTRASOUND equal or less than 13 weeks Indications and advantages: • confirmation of intrauterine pregnancy/ early pregnancy failure • best estimation of G.A. • Evaluation of vaginal bleeding • Evaluation of ectopic pregnancy • Confirmation of multiple pregnancy • Evaluation of pelvic, ovarian or uterine pathology
FIRST TRIMESTER ULTRASOUND GUIDELINES FOR DATING PREGNANCY
FIRST TRIMESTER ULTRASOUND NUCHAL TRANSLUCENCY • 11 to 14 wks • =/> 3 mm • Screening for fetal chromosomal abnormalities • screening for trisomy 21
SECOND & THIRD TRIMESTER NON-BIOMETRIC PARAMETERS • Uncertain of menstrual dates • Measurement disparity in late trimester • Narrow down error in estimation gestational age TRANSCEREBELLAR DIAMETER (TCD) - Numerically equivalent to the number of weeks of gestation
SECOND & THIRD TRIMESTER NON-BIOMETRIC PARAMETERS COLONIC GRADE • >/= 16 weeks- grade 1, anechoic lumen • at 26 weeks & more- grade 2- lumen appears more echoic • >/= 36 weeks- grade 3, lumen becomes brigther
SECOND & THIRD TRIMESTER DISTAL FEMORAL EPIPHYSES (DFE) • at least 32-33 weeks PROXIMAL TIBIAL EPIPHYSES (PTE) • Seen at 35 weeks PROXIMAL HUMERAL EPIPHYSES (PHE) • at 38 weeks or more • reliable predictor of term gestation
SECOND & THIRD TRIMESTER SIGNIFICANCE OF THE RATIOS • Cephalic Index (CI)- • BPD/OFD X 100 (74-83) • > 83- brachycephaly –may suggest a genetic abnormality • < 74 – dolichocephaly – seen with oilgohydramnios & breech presentation
SECOND & THIRD TRIMESTER • FL/AC RATIO –evaluating skeletal dysplasia - < 0.16 suggestive of a lethal type • HC/ AC RATIO- determines growth lag; high ratio –implies fetal malnutrition/IUGR • FL/BPD RATIO- can be used as one of the screening parameters for Down’s syndrome ( short femur & normal BPD= high ratio)
BIOPHYSICAL PROFILE • Gold standard for antepartum fetal surveillance WHEN TO REQUEST? -Antepartum testing started @ 26-28 weeks if with maternal complications -@ 32-34 weeks for high risk patients
BIOPHYSICAL PROFILE HOW FREQUENT? • Repeated weekly • Most authors suggest 2x/week BPS &NST for: 1. IDDM 2. GDM with previous stillborn 3. IUGR 4. Post term pregnancy 5. Preeclampsia
BIOPHYSICAL PROFILE What are the signs of fetal hypoxia? Chronic Hypoxia (compensated) 1. Oligohydramnios 2. Asymmetric (head-sparing) IUGR Acute Hypoxia (non-compensated) 1. Abnormal fetal heart rate changes • Non-reactive NST • (+) CST MODIFIED BPS -uses 2 parameters, NST ( acute marker of fetal compromise) & AFV (chronic marker)
BIOPHYSICAL PROFILE Nueral Control of Fetal Biophysical Activities
BIOPHYSICAL PROFILE Note: In pregnancy complicated by IUGR, DOPPLER VELOCIMETRY studies will enhance the perfomance of BPS – changes in Doppler findings occur 4 days prior to the deterioration of BPS
DOPPLER VELOCIMETRY A sonologic procedure to assess maternal and fetal vascular resistance (vasoconstricted/vasodilated) the state of fetal perfusion.
DOPPLER VELOCIMETRY To whom should we request it for? 1. Diabetes 2. Maternal HPN 3. Autoimmune Diseases - SLE, APAS, Collagen vascular disease 4. Anemia 5. Post term Pregnancy 6. Unexplained Recurrent Pregnancy losses 7. Discordant multifetal pregnancy 8. IUGR
DOPPLER VELOCIMETRY UTERINE ARTERY WHAT ARE THE ABNORMAL RESULTS? • Presence of notching • Increase indices (SD, RI, PI) AND IT’S SIGNIFICANCE? • Increase in the utero-placental resistance (vasoconstriction) • Higher chance of pregnancy complications
DOPPLER VELOCIMETRY UMBILICAL ARTERY vasoconstriction increase intraplacental resistance elevated indices decreased fetal perfusion fetal hypoxia then IUGR
DOPPLER VELOCIMETRY ABSENT END DIASTOLIC FLOW (AEDF) • highest risk to develop adverse perinatal outcome • the mean duration from AEDF to onset of fetal distress is 6-8 days
DOPPLER VELOCIMETRY REVERSED END DIASTOLIC FLOW (REDF) • most extreme form of intraplacental vascular resistance • diagnosis to distress interval 4.2 +/- 1.4 days with perinatal moratality rate of 50%
DOPPLER VELOCIMETRY MIDDLE CEREBRAL ARTERY What is an abnormal result? DECREASED INDICES- brain sparing reflex Remember: fetal hypoxia induces compensatory reflex preferential blood flow to the brain (MCA dilatation=decreased indices) while vasoconstriction in the less vital organs
DOPPLER VELOCIMETRY NOTE: A sudden restoration of MCA indices to normal or higher or increasing indices from a serial decreasing pattern is omninous= failure of the fetal cerebral vessels to vasodilate = acute fetal brain injury
ROLE OF COLOR DOPPLER IN THE DIAGNOSIS OF PLACENTA ACRRETA Patients who are at high risk to develop abnormally adherent placenta includes: • Multiparity • Hx of previous CS • Hx of previous curettage • Placenta previa implanted anteriorly in the LUS
ROLE OF COLOR DOPPLER IN THE DIAGNOSIS OF PLACENTA ACRRETA • Unusually intense blood flow within the sonolucent space beneath the placenta • Hypervascularization within the placenta and non placental tissues • Turbulence of flow in areas where placentas appears to have lost parenchyma and within placenta lacunae
CONGENITAL ANOMALY SCAN Should be done routinely in a 20-24 weeks gestation • Lowers perinatal mortality • Lethal malformations-corrected early or appropriate timing of delivery to allow surgical intervention; if not amenable to surgery, early counseling
GYNECOLOGIC ULTRASOUND ADVANTAGES OF TVS OVER TAS • Patient discomfort • Clearer images • Eliciting pain and tenderness • Earlier diagnosis of pelvic pathology • Good for obese patients and with abdominal scars
GYNECOLOGIC ULTRASOUND DISADVANTAGES OF TVS OVER TAS • Discomfort & pain to pxs with intact hymen and postmenopausal • Large pelvic masses • Refusal of the procedure
HYSTEROSALPINGOSONOGRAPHY • Evaluates tubal patency • primary investigative tool for infertility When it is performed? First part of the menstrual cycle (Day 10-12)
HYSTEROSALPINGOSONOGRAPHY • advantage of eliminating the risk of X-ray exposure & hypersensitivity to radiographic contrast media • Evaluation of endometrial pathology • Evaluation of ovaries for follicular growth • Evaluation of pelvic organs & structures for lessions and masses