OB GYNE ULTRASOUND concepts

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OB GYNE ULTRASOUND concepts its clinical
correlation

• Jan Charmaine Almonte-Saret M.D., FPOGS, FPSUOG

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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

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FIRST TRIMESTER ULTRASOUND

• GUIDELINES FOR DATING PREGNANCY

STAGE OF DEVELOPMENT GESTATIO-NAL AGE (WEEKS) LEVEL OF B-HCG
Gestational sac 5 weeks 1,000-2,000 mIU/L
Gestational sac with yolk sac 5.5 weeks 7,200 mIU/L
Gestational sac with yolk sac embryo 6 weeks 10,800 mIU/L
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FIRST TRIMESTER ULTRASOUND

• NUCHAL TRANSLUCENCY
• 11 to 14 wks
• /gt 3 mm
• Screening for fetal chromosomal abnormalities
• screening for trisomy 21

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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

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SECOND THIRD TRIMESTER

• NON-BIOMETRIC PARAMETERS
• COLONIC GRADE
• gt/ 16 weeks- grade 1, anechoic lumen
• at 26 weeks more- grade 2- lumen appears more
  echoic
• gt/ 36 weeks- grade 3, lumen becomes brigther

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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

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SECOND THIRD TRIMESTER

• SIGNIFICANCE OF THE RATIOS
• Cephalic Index (CI)-
• BPD/OFD X 100 (74-83)
• gt 83- brachycephaly may suggest a genetic
  abnormality
• lt 74 dolichocephaly seen with oilgohydramnios
  breech presentation

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SECOND THIRD TRIMESTER

• FL/AC RATIO evaluating skeletal dysplasia
• - lt 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 Downs syndrome ( short
  femur normal BPD high ratio)

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BIOPHYSICAL PROFILE

• Gold standard for antepartum fetal surveillance
• WHEN TO REQUEST?
• -Antepartum testing started _at_ 26-28 weeks if with
  maternal complications
• -_at_ 32-34 weeks for high risk patients

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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

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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)

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BIOPHYSICAL PROFILE
Nueral Control of Fetal Biophysical Activities
BIOPHYSICAL PARAMETER CNS CENTER GESTATIONAL AGE
Fetal tone Cortex- subcortical area 7.5-8.5 wks
Fetal movement Cortex- nuclei 9 wks
Fetal breathing Ventral surface of 4th ventricle 20-21 wks
Fetal Heart Reactivity Medulla Posterior Hypothalamus 24-26 wks
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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

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DOPPLER VELOCIMETRY

• A sonologic procedure to assess maternal and
  fetal vascular resistance (vasoconstricted/vasodil
  ated) ? the state of fetal perfusion.

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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

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DOPPLER VELOCIMETRY

• UTERINE ARTERY
• WHAT ARE THE ABNORMAL RESULTS?
• Presence of notching
• Increase indices (SD, RI, PI)
• AND ITS SIGNIFICANCE?
• Increase in the utero-placental resistance
  (vasoconstriction)
• Higher chance of pregnancy complications

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DOPPLER VELOCIMETRY

• UMBILICAL ARTERY
• vasoconstriction
• increase intraplacental resistance
• elevated indices
• decreased fetal perfusion
• fetal hypoxia then IUGR

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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

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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

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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
  dilatationdecreased indices) while
  vasoconstriction in the less vital organs

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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

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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

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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

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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

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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

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GYNECOLOGIC ULTRASOUND

• DISADVANTAGES OF TVS OVER TAS
• Discomfort pain to pxs with intact hymen and
  postmenopausal
• Large pelvic masses
• Refusal of the procedure

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GYNECOLOGIC ULTRASOUND
MENSTRUAL CYCLE ENDOMETRIUM OVARY
Menstrual phase Thin echogenic line Developing follicles (5-10)
Early proliferative Isoechoic Leading follicles
Late proliferative Trilaminar Dominant follicles (18-24)
Secretory phase Thick Hyperechoic Corpus luteum
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HYSTEROSALPINGOSONOGRAPHY

• Evaluates tubal patency
• primary investigative tool for infertility
• When it is performed?
• First part of the menstrual cycle (Day 10-12)

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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

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THANK YOU