ultrasound evaluation of first trimester-b
TRANSCRIPT
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 1
ULTRASOUND EVALUATION OF FIRST TRIMESTER (cont.)
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 2
P/V bleeding in first trimesterSubchorionic bleeding
Spontaneous abortion
Ectopic pregnancy
Gestational trophoblastic
neoplasia(GTN)
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 3
Spontaneous abortionThreatened
cervix closedImpending/inevitable
open cervical OSIncomplete
retained tissuetrophoblastic flow
Completeusually endometrium is empty
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 4
Spontaneous abortion: ultrasound findingsSpectrum from threatened to complete
abortionnormalabnormal gestational sac:
o small, irregular, located in lower uterine segment or cervix
o movement of sac up and down canal withuterine contractions
large subchorionic hemorrhagefluid, debris within endometrial canalempty endometrial canal
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 5
Living embryoDead embryoEmpty gestational sac/blighted embryoSubchorionic haemorrhageMolar pregnancyCervix is closed
Threatened abortion: ultrasound
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 6
Inevitable/Impending abortionMay get any/some of the findings in
threatened abortion plus:Abnormal gestational sac:Small, irregular, located in lower uterine
segment or cervixMovement of sac up and down in cervical
canal with uterine contractionsOpen cervical canal
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 7
Deformed, irregular gestational sac
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 8
Open cervix: red arrow
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 9
Impending abortion Impending
abortion open cervix GS in
cervix
movement of sac
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 10
Incomplete abortionThickened, irregular endometrial stripe
Echogenic retained products of conception
Fetal parts
Open cervical canal
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 11
Retained products of conception: arrows
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 12
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 13
Complete abortion
Endometrium is usually empty and
endometrial stripe is usually normal
There may be some little fluid/hemorrhage
within the endometrium
Cervical canal is closed
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 14
Complete abortion: empty uterus
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 15
Gestational Trophoblastic Neoplasia (GTN)Spectrum including molar pregnancy, invasive
mole, choriocarcinoma, & placental-site
trophoblastic tumour (PSTT)
Paternal karyotype
fertilization of chromosomally empty egg
Pts present with markedly elevated β-HCG levels,
nausea
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 16
GTN: ultrasound findingsHeterogeneous, irregular endometrial mass
echogenicity variable“cluster of grapes” relatively late
appearancevascular: PSV, RI
+ Myometrial invasionFetus w/ a “thick placenta”Theca lutein cysts
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 17
Molar pregnancyComplete molar pregnancy:Chromosomal DNA exclusively paternal in originOvum with absent or inactive maternal
chromosomes is fertilized by a normal haploid sperm
Adiploid karyotype of 46,XX is produced (70-85%)
No fetal developmentPlacenta is entirely replaced by abnormal
hydropic chorionic villi with excessive trophoblastic proliferation
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 18
Complete molar pregnancy: ultrasound
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 19
Complete molar pregnancy: ultrasound
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 20
Molar pregnancy: theca lutein cysts
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 21
Partial molar pregnancyMost result from fertilization of a normal
ovum by 2 haploid spermsTriploid karyotype pf 69,XXX; 69,XXY; or
69,XYYWell developed but generally anomalous
(triploid) fetal tissuesHydropic degeneration of placental villi is
focal, interspersed with normal placental villiTrophoblastic proliferation is mildCoexisting embryo/fetus/GS
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 22
Partial molar pregnancy: ultrasound
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 23
Partial molar pregnancy: ultrasound
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 24
Fetal anatomy in the first trimester
Normal anatomy
Clear potential for early screening of
congenital anomalies
Developmental pitfalls
Nuchal translucency
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 25
Normal limb buds
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 26
Choroid plexus
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 27
Developmental pitfalls Developing
rhombencephalon normal finding contributes to
development of 4th ventricle, brainstem, cerebellum
cystic space in posterior fossa
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 28
Rhombencephalon
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 29
Developmental pitfallsFetal bowel normally
herniates into the base
of the umbilical cord in
the first trimester
echogenic mass near
cord insertion
< 7 mm across base
resolves by 12 wks
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 30
PHYSIOLOGIC HERNIATION OF BOWEL
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 31
Nuchal translucencyThin membrane found at approx 10 wks GA
along posterior neck
> 3 mm is abnormal, esp. if septated
Ass. with trisomy 21,18; Turner’s Syndrome
risk of congenital anomalies even if karyotype is normal
Regression is not reassuring
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 32
Normal nuchal translucency
2.6mm 2.7mm
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 33
Abnormal nuchal translucency
4.5mm
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 34
Nuchal translucencyShould make this measurement in all obs
ultrasound examinations between 10-14 wks
Measure in neutral position
Pitfalls
compression against uterine wall
extension or flexion of fetal neck
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 35
MATERNAL CAUSES OF PELVIC PAIN IN THE 1ST TRIMESTER
Hemorrhage / rupture of corpus luteum cyst
Ovarian hyperstimulation syndrome
Ovarian torsion
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 36
Haemorrhagic cysts
Changes over time - ultimately resolves
Thin wall (may be vascular)
Increased through transmission
No central blood flow
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 37
Haemorrhagic cystsDiffuse, low level
echoesLace-like or spider
web pattern of internal echoes/septations
Echogenic clot may be mobile or lenticular and adherent
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 38
Ruptured cyst
Crenated appearance
Adjacent free fluid
+/- internal debris
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 39
Ovarian hyperstimulation syndromeComplication of ovulation induction
incidence: pregnancy
estradiol > 4000 pg/ml
Bilaterally enlarged, multi-cystic ovaries
Complications include: cyst hemorrhage, cyst
rupture, ovarian torsion
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 40
Ovarian hyperstimulation syndrome: ultrasound evaluationAssess cysts for:
debris
irregular shape
adjacent free fluid
Document ovarian blood flow
Assess for ascites, pleural effusion
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 41
Ovarian hyperstimulation syndrome: ultrasound evaluation
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 42
Ovarian hyperstimulation syndrome: pleural effusion
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 43
Ovarian torsionClinical presentation: acute onset of severe pelvic
pain, usually no fever, normal WBC
More common on right
Differential diagnosis: hemorrhagic cyst, cyst
rupture, renal colic, appendicitis
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 44
Ovarian torsion: ultrasound featuresEnlarged ovary
check for underlying mass
heterogeneous central stroma
edema / infarct
peripheral cysts
+/- Free fluid
Appearance quite variable
Tuesday, April 11, 2023 Ultrasound evaluation of first trimester 45
Ovarian torsion: Doppler findingsVariable
varying degrees of torsionDecreased flowReversed diastolic flowDecreased or absent venous flowComplete absence of flow