7/6/2015

1

Obstetric Ultrasound 2nd/3rd Trimesters

Mary C. Frates, MD, FACR

Fetal Lie (Vtx vs Breech)

–Self explanatory

Cervix/Cord/Placenta/Fluid

Measurements (Biometry)

Survey/ BPP

ACR/AIUM/ACOG/SRU guidelines for Obstetric US

Cervix

Normal > 3 cm, closed

Shortened and closed (effaced)

Dilated internal os (funneled)

May be dynamic

May need TVS

Rx: cerclage/pessary/bedrest

Karinskas- normal TA cervix

Cervix - TA

Daska long cervix full bladder.jpg

Cervical length changes

with pressure/ bladder distention

Ambrosino TV cervix looks normal 31 wks.jpg

Normal

Open

Normal

Normal TV

7/6/2015

2

Stevens 27w dilated entire Cx canal and open external os 11 mm.jpg Simmon feet in canal 18

Open

Umbilical Cord

3 VC

2 arteries and one vein

2 VC

one artery and one vein (same size)

increased risk anomalies/IUGR

Vellamentous Cord

Inserts into the membranes

normal 3VC color.jpgPamphile 2 VC color.jpg

3 VC

2 VC

Broderick funic presentation ruptured membs Cord presenting tranverse lie

Funic

Presentation

Verdieu vellamentous CI

Vellamentous CI

Placenta

Location re: cervix

Location re: uterine wall

Staging- no real value

decisions based on fetal status

Masses

7/6/2015

3

Placenta Previa

Relationship of placenta to internal os

Established AFTER 16 weeks

No previa (over 2 cm away)

Low Lying (within 2 cm)

Previa – overlying internal os

1/200 births

Placenta Previa*

If low lying or previa is found: follow-up at 32 weeks

If still low lying or previa: follow-up at 36 wks

Consider TVS with color to exclude vessels over the os

*NIH Executive Summary on Fetal Imaging; Ob Gyn2014; 123:1070

Placenta previa 27 wks Placenta Marginal previa TV.jpgAnger.jpg

Placenta Previa

Low-lying Previa

Ho vellamentous cord splits between ant and post placs

Vasa Previa

Ho vellamentous cord splits between ant and post placs

Vasa Previa

Placenta Acreta

Abnormal placental attachment

Typically at a scar

Acreta-Increta-Percreta

Myometrial depth

Increased risk after C-section

Increased risk with venous lakes, anterior previas

7/6/2015

4

Watson placenta acreta 22 wks

Placenta Percreta

22 wks

Dinino lateral percreta 30wks.jpg

Placenta Acreta Lateral

30 wks

Placenta Cysts vs Tumors

typically simple

fetal surface

near cord insertion

if large, associated

with IUGR

chorioangioma

solid

anywhere

typically benign

if large, vascular shunting and fetal hydrops

Abramson placental cysts IUGRLeitner chorioangioma

31 wks

Placenta Cyst Mass

Amniotic Fluid

Oligohydramnios

Mild-moderate-severe

Polyhydramnios

Mild-moderate-severe

Subjective vs AFI

4 Quadrant measurements

Look for an explanation

Brumfield absent kidneys bladder severe oligo TRV.jpg

Oligohydramnios

7/6/2015

5

Baker severe poly trach atresia w fist

Measurements (Biometry)

Know the rules!

Head

Abdomen

Femur

Measurements

Follow the rules!

optimize the image

correct plane and correct endpoints

small error pre-viable is not clinically significant

error more important at extremes

– recognize the large scale errors

Head Measurements: BPD

largest possible, along skull base

symmetrically positioned 3rd ventricle/

thalami

falx down the middle, CSP anteriorly

calvaria smooth and symmetric

cursers:

outer to inner

leading edge to leading edge

Bennett bad head orbits included.jpg

Mistakes

Correct

Abdomen Diameter Measurements

level of liver (largest intra-abdominal organ in fetus)

stomach and intrahepatic umbilical vein

Junction of left and right portal vein

skin edge to skin edge

7/6/2015

6

Abdominal Measurements

When struggling-

Round is best

Keep AD measurements within 10 mm of each other

This gives a pretty good estimate even without other landmarks

berrios 30wks bad ADmeasurements prone.jpg

Mistake

Fetus is prone-

landmarks obscured by spine

berrios 30wks bad ADmeasurements prone.jpg

Correct Measurements: Femur

long axis of the bone (ossified portion) parallel to transducer

epiphysis is excluded

measure at junction of cartilage and bone NOT the longest echogenic point (the “distal

femoral point”) which has no anatomic

correlate)

Femur measurement 35wks depth too high.jpg MacDougall good measurements

Image too tiny to see landmarks

Mistake

Correct

Bad AC measurement 1.jpg

EFW 3971 gms

BW 4850 gms Vaginal delivery c/b shoulder dystocia

Severe hypoxemia; baby died DOL 2 hypoxemia and acidosis

all of abdominal

wall is not included

Mistake

7/6/2015

7

Measurements (Biometry)

>90 % macrosomic

> 4500 gms –C section (9,15)

> 4000 gms in diabetic (8,14)

< 10% IUGR

80% small/20% sick

only < 5% are really IUGR

2/3 trimester: Anatomy

CNS

Heart

Thorax

Abdomen

GI/GU

Abdominal wall

Head

Normal/ normal variants

Chiari Malformation

Lemon/Banana

Hydrocephalus

Hydranancephaly

Holoprosencephaly

Cerebral Ventricles

plane must be level

Off axis measurement will increase

size

always use the smallest technically accurate measurement

all errors result in larger size ventricle

brea hydroecphalus.jpgAli borderline ventricle but dangling choroid 18w.jpg

Lateral Ventricle

Collins CP cyst 19wks.

Choroid Plexus

Cysts

7/6/2015

8

Chiari Malformation

Lemon/ Banana

Spine defect

** Need Sagittal Image

Cardoso LS meningocele 18 wks PF.jpgbad measurement down.jpg

Smith lumbar meningomyelocele Trv.avi

Fluid in the Brain

Holopros

No

Yes

Hydranen

Yes

No

Hydroceph

Yes

Yes

Falx

Cortex

Avignon holopros

Holoprosencephaly

Falx No

Cortex Yes

Sutton hydranencephaly first survey 31wks.jpg

Hydranencephaly

Falx Yes

Cortex No

7/6/2015

9

Kosinski severe hydrocephalus, prob aqued stenosis.jpg

Hydrocephalus

Falx Yes

Cortex Yes

Heart

4 chamber

Aorta and Pulmonary Outflow Tracts

3 Vessel View

Clips are mandatory

Color?

lazard nml heart 4 Ch 35w.jpg

Normal 4 ch; nml Ao L side down Wilson; nml PA

wilson

Ortiz vsd only seen on clip

Cine clip is critical Poynton hypoplastic LV

20 wks

7/6/2015

10

Bouchartd AV canal Tris 21

Heart

4 Chamber only is not enough

Technique critical with Ao and PA

Ao must be imaged in axial plane, with RV and septum on image

Lesser Tet nml 4 chamber Ewing TGA 33

3 vessel view Normal Guzman dillon TGA 3 vessel view missing one. Arevalo abnml 3VV

TGA

3VV

Thorax

Diaphragmatic hernia

CPAM/ sequestration

Tracheal/bronchial atresia

7/6/2015

11

Amiri L CDH chest

CDH

Conley huge CCAM fills entire R chest 21wks.avi

CPAM

Nastanski tracheal atresia

17 weeks

Tracheal Atresia

Abdomen/ Kidneys

Caliectasis/hydronephrosis

Posterior urethral valves

Multicystic dysplastic kidney

Autosomal recessive polycystic kidneys

Often affects fluid ()

Davis R UVJ 36 w , Silva hydronephrosis hydroureter 38wks.avi

Hydronephrosis

Reilly PUVs keyhole and ascites.jpg

Posterior Urethral Valves

7/6/2015

12

Vaughn MCDK sag 28wk.avi

Multicystic Dysplastic Kidney

Deming ARPCK 3.JPG Wentworth ARPCK

ARPCK oligo

Abdomen/ GI

Stomach

Dilated bowel loops

Perforation/ Meconium Ileus

Often affects fluid ()

Paige 18.5 wks missing LK called normal.

Trisomy 21

Duodenal Atresia

Louis prox jejunal obstruction 32w.aviSharma SBO 37wks.avinormal.

Small Bowel Obstruction

Proximal

More Distal Garabedian high SBO and mec peritonitis.jpg.

Meconium Peritonitis/ SBO

7/6/2015

13

Abdominal Wall

Gastroschisis

free floating loops of bowel

defect to the right of CI

ascites impossible

Omphalocele

membrane covered protrusion

Cord inserts into mass

ascites possible

Welch gastroschisis Vaughn gastrischisis 31w.avi

Gastroschisis

No membrane

Normal CI

Pamphile omphal Trv.jpg Joyce omphalocele no liver.avi

Omphalocele

+ Membrane

CI into mass

Douglas cleft lip nml coronal.jpg

Douglas cleft lip

and TGA

gregson 4gXX nml hand Suarez postaxial polydactyly 17wks mom has it. Diallo clenched hands Tris 18

Brea bilat club feet extra piece chrom 14.avi.

7/6/2015

14

Nucahl cord (Kosar)

Nuchal cord

Valdez 8-8 BPP extremity movement.avi

BPP: 2 AVF

2 Movement

2 Tone

2 Breathing

Sayag sticking tongue out 30 wks3D yawning fetus

And…. 2/3 Trimester

Measurements

Survey

Some abnormalities develop over time

Don’t call something unevaluable without considering it might be abnormal