Please enable JavaScript.
Coggle requires JavaScript to display documents.
Uterine environment in pregnancy, image, image, image, image, image, image…
Uterine environment in pregnancy
Maternal anatomy
Myometrium and Ovaries
Do NOT forget
to assess the
myometrium
and
ovaries
Fibroids
Most Important =
Proximity to Cx
Assess
size
and
location
Assess
interval growth
on each scan
Cervix
Normal Cx
Long and Closed
≥ 2.5cm (3cm at some sites)
Assessment
Use amniotic fluid as a window
Pitfalls
Bladder too full
LUS contraction
Cervical Incompetence
Beaking/Funneling :Opening of CX from Int Os
Rx: Cerclage
PROM
Early rupture of Membranes
No EV
(infection), do a
Translabial
instead
Placenta
Anatomy
Form
Basal Plate
Adjacent to MOTHER
Attaches to uterus/decidua
20 Cotyledons
Functional lobes
Contain chorionic villi
Chorionic Plate
Adjacent to FETUS
Fetal arteries/veins branch over surface
Amnion attaches here
Intervillous space: Maternal blood bathes chorionic villi
Discoid shape: central umbilical cord insertion
Placental Blood barrier
Function
Storage : Carbs, proteins, calcium, iron
Excretion: waste products
Nutrition :water, salts, carbs, fats, proteins, vitamins
Hormone Production: hCG, estrogen, progesterone
Respiration
O2 from Mom to Baby
CO2 from Baby to Mom
Assessment
Location, appearance, cord insertion and relationship to internal Cx os
location
Anterior / Posterior
Fundal
Rt or Lt Lateral
PREVIA or LOW LYING
Placenta Previa
g
Placenta Previa in the 3rdTrimester results in a c-sectionto prevent maternal hemorrhaging during a vaginal delivery
Always comment on the Placenta’s relationship to the Internal Os
Marginal and Complete Placenta Previa’s
What?
Placenta covering internal osof cervix
Diagnosed in 2ndTrimester
Often resolves with dev’tof LUS
Classic History:
painless bleeding 3rdtrimester
often asymptomatic
Cesarean delivery if
previa or “too close” at term (risk of hmrge)
Types
Low -Lying edge
<= 2cm
from Internal Os (Only used in the 3rdtrimester)
Marginal Previa:edge
touching
Internal Os
Complete Previa:edge
covers
Internal Os
Symmetric -
centered
over cervix
Asymmetric -
not centered
over cervix
3rd trim: all 3 are concerning
2nd trim: only last 2 are concerning (if complete or marginal>> follow up scan at
32-34w
Consider
EV
)
Tips and Tricks for CX/Placenta assessment
Have patient
void EARLY
on in the exam
Use
Amniotic Fluid
as a
window
to cervix (BLADDER empty)
Always
assess
at
beginning
, have patient void, reassess
later
in the study
Offer
EV
if indicated (why?)
Bladder empty
Very useful if
Low fetal head
Posterior Placenta
Thickness & Sonolucencies
Placental Sonolucencies
Intro
Most often considered a normal finding
Increased significance if:
Early presentation
Increased size and number
Common
IntervillousThrombosis
What?
Thrombosis of Placental Lake or
Blood Clot within intervillousspace
Placental Lakes
NOT CLINICALLY SIGNIFICANT , Increased incidence with gestational age
2D -Swirling maternal blood , Anechoic/Hypoechoic
No Flow on Doppler
Single or Multiple. Variable Size and Location
Common
Maternal blood within the intervillousspace
Uncommon
Tumour
Chorioangioma
Benign, vascular mass
? ↑hCG/ αFP
If Large/Multiple
AV shunting
Fetal compromise
US
Hypoechoic Solid mass
with flow within/feeder
Spectral doppler Fetal pulse rate
Usually near cord insertion, fetal side placenta / chorionic plate
Infarction
Localized area of ischemia
Caused by:
Thrombotic occlusion of uteroplacental(spiral) artery
Retroplacentalhematoma
Clinically insignificant
Associated with:
post term pregnancies
maternal hypertension
US
Triangular area of altered echogenicity
Abruption
Premature separation from myometrium
Types
Marginal, partial, complete
Revealed, concealed
Retroplacental, marginal
Outcome depends on: size and location
Associated with:
Trauma (MVA, fall)
RetroplacentalFibroids
Smoking/cocaine/BP
Clinically
+Pain +++
+Tense uterus
+Vaginal bleeding
+Fetal Bradycardia
US
Obstetric emergency:Often bypass SONO dept. Must deliver immediately
Retroplacentalhematoma
Marginal hematoma
No flow/Swirling
Evolving Echogenicity:
Acute bleed vs organized clot
Hyperechoic > Isoechoic > Hypoechoic
Accreta
Placental Abruption
Thickness
Normal placental thickness 2-4cm
Placentomegaly
4cm
Usually normal diagnosis
Non-specific diagnosis
Maternal Diabetes
Rh Incompatibility
Fetal Hydrops
Fetal Cardiac Overload
Placental Insufficiency
Thin Placenta
Maternal Hypertension/preeclampsia
IUGR
Placental Abnormality
Placental Texture
Early Second Trimester: Relatively Homogeneous
Late Second thru Third: Increasing Heterogeneity
Placental Membranacea
AKA: placenta diffusa
No differentiation of frondosum/laeve
Chorionic Villi cover most/all membrane area
Sonographic Appearance: Unusually thin placenta that seems to be EVERYWHERE!
Placental Calcifications
3rd trimester
Occur as placenta matures
Usually normal
+++ Calcsprior to 37w =↑ risk of adverse outcome
Outline the cotyledons
Placental Grading
