Dr. Sudhir Kumar ShuklaBhi la i (C.G.)

SONOGRAPHY EVALUATION OF UMBILICAL CORD

& CORD ANOMALIES

WHY UMBILICAL CORD IMPORTANT Umbilical cord is a Lifeline, narrow tube like structure connects the developing baby to placenta.

The cord is sometimes called the baby supply line It delivers nutrient and oxygen to the baby and removes waste product.

ROLE OF SONOGRAPHY IMPORTANTEarlier it was just counting the number of vessel but now playing an important role in haemodynamics. It is actively involved in indentifying important process like

1. Foetal growth restriction.

2. Preeclampsia.

3. Diabetes.

4. Chromosomal defect or genetic syndrome.

MORPHOLOGY

50-60 cms long usually covered by single layer of amniotic epithelium. vessels are embeded in wharton’s jelly.

The characteristic structure of umbilical cord is determined by the helical course of arteries around vein. Between umbilical ring and placental insertion.

MORPHOLOGY

WHARTON’S JELLY

Jel like structure.

No proper vasculature.

Functions - give flexibility and strength to cord.Transfer of water & metabolites between amniotic fluid and umbilicalcord vessels. active throughout pregnancy.Helps in remodeling and embryogenesis.

Umbilical vein

Umbilical artery

Structure is very dynamic and Influenced by a number of factors including –

1) Gestational age.

2) Amount of amniotic fluid and it’s composition.

3) Foetal movements.

4) Foeto placental haemodynamics.

5) Maternal complication during pregnancy

The evaluation of umbilical cord can be done long axis view or transverse view, Cross sectional view is more appropriate because it allows quantification not only of umbilical vessel size but also amount of Wharton’s jelly.

MORPHOLOGY

Cord begins to form at 5 weeks of gestation it becomes longer until 28 weeks of pregnancy until it reaches average length of 22 to 24 inches (55 -60 cm.).

LENGTH OF CORD

Normal cord length is 50-60 cm.

CORD LENGTH

IMAGES

ABNORMAL CORD LENGTH SHORT CORD < 35 cm is defined as short cord, may lead to foetal distress, placental abruption, prolonged labour.

LONG CORD> 80 cm is defined as long cord, higher occurrence of cord around neck, cord around body, cord knot, cord prolapse and cord compression.

LONG

SHORT

Umbilical artery :-1.2 + 0.4 mm. at 16 weeks 4.2 + 0.4 mm. at term of gestation.

Umbilical vein :- 2 + 0.6 mm. at 16 weeks.8.2 + 0.8 mm. at term of gestation.

Progressively increases up to 32 weeks than by a plateau towards end of pregnancy due to reduction in water content of Wharton’s jelly .

A significant relationship between umbilical cord diameter and cross sectional area and foetal biometry.

Wharton’s jelly plays a metabolically active role throughout the pregnancy.

DIAMETER

UMBLICAL CORD can be defined as

(A) LEAN CORD

(B) LARGE CORD

(A)LEAN :-If it’s sonographic cross – sectional area is below 10th percentile for gestational age

LEAN CORD ASSOCIATED WITH

1. Oligohydramnios 2. Foetal distress. 3. SGA Foetus4. Meconium stained amniotic fluid. 5. Adverse pregnancy outcome.

1. Umbilical cord tumors2. Urachal cyst3. umbilical cord mucoid degeneration4. Omphalomesenteric cyst.5. Gestational diabetes mellitus.6. Macrosomia.

LARGE CORD ASSOCIATED WITH

(B) LARGE :- If it’s sonographic cross - sectional area is above 90th percentile for gestational age.

• Colour flow mapping could be used to enhance the definition of umbilical cord.

• A normal umbilical cord is coiled like a teIephone cord. When the umbilical cord twisted beyond It is called a hypercoiled umbilical cord when the cord has too few coils, it is called a hypocoiled umbilical cord.

UMBILICAL CORD COILING

Sonographic umbilical coiling index is defined as number of vascular coil in a given cord. Usually 1 coil / 5 cm of umbilical cord length and may coil as many as 40 times.

< 10th percentile – hypocoiled.

10th – 90th percentile – normocoiled .

>90th percentile – hypercoiled.

Whether an umbilical cord is normal, hypercoiled or hypocoiled is dependent on the number of coils present in the cord – this is known as the umbilical coiling index (UCI).

UMBILICAL CORD COILING

A TYPICAL COILING – Bizarre coiling pattern.

Normocoiled

A TYPICAL COILING

IMAGES

Bizarre coiling pattern.

Both the hypercoiled and the hypocoiled umbilical cord can result in the undesirable result of a decrease in the amount of nutrients sent to the foetus, resulting in intrauterine growth restriction (IUGR) and increases the risk of foetal death, poor foetal development or a stillbirth.

UMBILICAL CORD COILING

Hypercoiled

Hypocoiled

NORMAL CORD INSERTION

Normal placental insertion is central and can be paracentral.

Normal umbilical cord insertion into a laterally implanted placenta.

Normal umbilical cord insertion into the Posterior placenta

NORMAL UMBILICAL CORD INSERTION

Cord Insertion

* Marginal insertion (Battedore Placenta)

* Furcate insertion

* Velamentous insertion

* Vasa praevia

ABNORMALITIES OF U. CORD INSERTION

Cord Insertion

ANOMALITIES DEFINITION INCIDENCE SIGNIFICANCE

Furcate insertion Umbilical vessels separate from Rare cord substance before their insertion into the placenta

Marginal insertion Battledore placenta 7 % at term Cord being pulled off cord insertion at the placental during delivery of the

margin placenta * 2% - 15 %* associated with preterm labour (?)* US

Velamentous Umbilical vessels separate in 1.1 % more frequently with insertion the membranes at a distance twins

from the placental margins. 28% of triples. Reach surrounded only by a fold of amnion

UMBILICAL CORD ABNORMALITIES

MARGINAL INSERTION

VELAMENTOUS INSERTION

VASA PREVIA1) One or more vessel from cord or placenta cross the cervix underneath the baby.

2) Vessels unprotected by the Wharton’s jelly in the cord or tissue in the placenta.

3) Tear on vessel – Life threatening bleeding.

4) Hypoxia if the vessels are compressed between baby & birth canal.

5) Foetal mortality 33 – 100% if not diagnosed prenatally.

6) Increased risk associated with a) Velamentous insertion of the cord. b) Placenta previa.

Doppler scan to detect Vasa Previa

VELAMENTOUS INSERTION – VASA PREVIA

Normal physiological herniation of bowel

Physiological herniation of bowel into the base of the umbilical cord is part of the normal Developmental sequence which occurs at about the 6th to 8th , and by 8th to 12th mid gut herniates back into the base of the umbilical cord.

Omphalocele is midline abdominal wall defect with herniation of the abdominal content into the base of the umbilical cord.

U/S FINDINGS:-

Omphalocele looks like a central mass protruding from the anterior abdominal wall. It varies in size and is covered by a membrane . It usually contains small intestine and liver. There can be other organs protruding to the omphalocele such as large intestine, bladder, stomach, spleen.

OMPHALOCELE

Polyhydramnios and ascitis.

OMPHALOCELEColour doppler will be useful for umbilical cord demonstrated.

Omphalocele with stomach entering the omphalocele sac.

23 weeks liver is within the sac and the hepatic vessels Are demonstrated by colour doppler.

* May be found along the course of the cord usually close to foetus (foetal end) or close to the insertion site.

* TRUE CYSTS :- > Epithelium lined

> Remnants of the allantois> Coexist with patent urachus.

* FALSE CYSTS :- > More common. > Due to degeneration / Edema of Wharton’s jelly > Single cyst may resolve completely. > Multiple cysts may be associated with miscarriage / aneuploidy. * Difficult / impossible to differentiate true cyst from false cyst.

UMBILICAL CORD CYSTS

True Cyst

* Cystic lesions within the umbilical cord.* May be pseudocysts or true umbilical cord.* Most Umbilical cord cysts disappear by the end of 1st trimester. if they persist beyond 12 weeks or if the cyst are multiple, they associated with a bad prognosis. Certain Trisomies and foetal anomalies and linked to the presence of umbilical cord cysts. * The cord cyst must be differentiated from the more echogenic yolk sac which is seen outside the amnion .

UMBILICAL CORD CYSTSULTRASOUND IMAGES

• This second trimester pregnancy shows evidence of multiple umbilical cord cysts (in this case, there are two umbilical cord cysts). The colour doppler ultrasound images show anechoic cystic structures with absence of flow, suggesting umbilical cord cysts .

• Associated with increased morbidity and mortality for the fetus .

• Higher risk of aneuploidy.

ULTRASOUND IMAGES

MULTIPLE UMBILICAL CORD CYSTS

NORMAL VESSELS

AND

VASCULAR ABNORMALITIES

NORMAL UMBILICAL CORD VESSELS

(Panel A) Transverse view of a normal umbilical cord shows the characteristic "Mickey mouse" appearance with two arteries (a) and one vein (v) surrounded by the Wharton's jelly.

(Panel B) Longitudinal view of a three-vessel umbilical cord shows the arteries (a) looping around the vein (v). Upper panel, conventional two-dimensional ultrasound.

Umbilical cord demonstrating 2 arteries of equivalent size and the larger umbilical vein.

Umbilical arterie seen lateral to the bladder.

DOPPLER IMAGES

Colour doppler

Colourdoppler

Grayscale

Hyrtl anastomosis is an interarterial anastomosis between the umbilical arteries, approximately 3 cm from the placental cord insertion seen in at least 95 % of all placenta.

The effect of this anastomosis is to equalize pressure between the placental lobes. If the anastomosis does not equalize the blood flow between the arteries. Placental will be asymmetric is size.

HYRTL ANASTOMOSIS

3D

1. One percentage of single tone and 5% of multiple pregnancies (Twin , triplets & more).

2. Left umbilical artery is absent either A) Primary agenesis of vessel. B) Atrophy or atresia of an existing artery.

3. Detected at prenatal sonography by A) (1) Cross sectional. (2) Longitudinal image. B) Lateral to the bladder wall.

TWO VESSELS CORDS SINGLE UMBILICAL ARTERY

4. SUA – Larger may approach the size of umbilical vein usually greater than 4 mm between 20-36 weeks.

5. Cord should be assessed at multiple level , artery may fuse near placenta

6. Identification SUA poor :- 1) Oligohydramnios. 2) Small cord size early pregnancy. 3) Multiple pregnancy.

SINGLE UMBILICAL ARTERY

7. Isolated SUA :- No growth problems of baby.

8. Associated with Chromosomal abnormality Trisomy 13 Trisomy 18

9 Other tests:- Aminocenetesis.

Foetal echo. Post natal assessment required.

10. Associated with velamentous cord insertion.

SINGLE UMBILICAL ARTERY

SINGLE UMBILICAL ARTERY

11) Anomalies associated with

Musculoskeletal.

Urogenital

Cardiovascular

Gastrointestinal.

Central Nervous

Other.

Musculoskeletal :- Cleft lip and palate. Clubfeet. Rocker bottom feet. Polydactyly. Clino-syndactyly. Limb reduction defects11. Vertebral anomalies. Rib and sternal anomalies.

Urogenital Renal agenesis. Renal hypoplasia or dysplasia. Horseshoe kidneys. Hydroureter and Hydronephrosis. Mullerian duct agenesis or anomalies. Wolffian duct agenesis or anomalies. Malformed external genitalia.

Cardiovascular VSD. ASD. Patent Ductus Arteriosus. Truncus anomalies. Valvular anomalies.

Gastrointestinal Esophageal atresia or stenosis.

T-E fistula. Imperforate anus. Gut malrotation. Omphalocele and gastroschisis.

DETAILS

CNS Neural tube defects. Anencephaly.

Meningomyelocele. Holoprosencephaly.

Hydrocephalus. Microcephaly.

Hydrops fetalis.

Other Eye abnormalitiesPulmonary hypoplasia or aplasia.Laryngeal atresia.Diaphragmatic hernia.Cystic hygroma.Webbed neck.Hydrops fetalis.

Difference in diameter of two umbilical arteries at least 1 mm in three different places.Smaller artery - high resistance flow.Usually benign does not affect the development of the fetus.

Associated with

1) Higher incidence of morphologic placental alteration. A) placenta bipartite. B) placenta succenturiata.

2) Absence of hyrtl anastomosis.

3) Anomalous placental insertion- (marginal, velamentous).

DISCORDANT UMBILICAL ARTERY

Green lines in section a show the tangential course of the arching vessel with respect to the foetal stomach (*). The left portal vein branch (>) and ductus venosus ( )are visible. In section b a colour change allows indentification of the ductus venosus (“ aliasing” caused by flow acceleration). Caption : hepatic veins (+).

UMBILICAL VEINNormal anatomy: intraabdominal course of the Umbilical vein and union with portal system.

A PERSISTENT RIGHT UMBILICAL VEIN

U/S Images

A PERSISTENT RIGHT UMBILICAL VEIN

RUV Obliterate around 4th week of gestation. & Disappears by the seventh week of gestation. Persistent right umbilical vein is a uncommon vascular pathology. Left umbilical vein occluded. Right umbilical vein persist.Causes of persistent right umbilical vein1) First trimester folic acid deficiency 2) Specific Teratogens such as retinoic acid.3) Early obstruction of the left umbilical vein form external pressure or

occlusion.

PRUV in the transverse section. The criteria used are:1) portal vein curve towards the Stomach.2) Foetal gall bladder located medially to the umbilical vein & stomach.3) Umbilical vein is abnormally connected to right portal vein instead to the left portal vein.4) Colour doppler is necessary .5) Usually detected in 2nd to 3rd trimester.6) An intrahepatic persistent right umbilical vein may be seen .7) Abnormally connected to right portal vein and foetal gall bladder is positioned medial to PRUV.PRUV can be intra & Extrahepatic.The former is much more commoner.

A PERSISTENT RIGHT UMBILICAL VEINUltrasound diagnosis

ASSOCIATIONS :- commoner with extrahepatic type.

Single umbilical artery especially in the extrahepatic type. Chromossomal anomalies . Triosomy 18 Noonan syndrome 8. Situs anomalies. Dextrocardia. Congenital cardiac anomalies. Congenital renal anomalies. Congenital gastrointestinal anomalies Vertebral anomalies.

A PERSISTENT RIGHT UMBILICAL VEIN

Four vessels cords result from the persistence of the Right umbilical Vein.

4 VESSELS CORDS(A) TWO VEINS AND TWO ARTERIES

(B) ONE VEIN AND THREE ARTERIES

Persistence of small vitelline arteries.

Allantoic or omphalomesenteric duct remnant is not true vessel.

(C) ONE VEIN, TWO ARTERIES AND DUCT

(D) ARTIFACTS

Exquisite view of the vessels wall and gives the impression of extra vessels.

5 AND MORE VESSELS CORDS

Numerous variations associated with conjoined twining.

Cords with unequal numbers of vessels at the foetal end and placental ends

Partial division of the primordial umbilical artery

Fails to divide primordial longitudinally in two umbilical arteries. division starts at placental end with 3- vessel on the placental end but 2 on foetal end.

ABNORMAL COURSE OR CONNECTION OF VESSELS

a)Ductus venosus agenesis

Very rare The return of the umbilical flow is via various ways

b) Replaced umbilical artery to superior mesenteric artery:-

Left umbilical artery is replaced (which means improperly connected ) to superior mesenteric artery and right umbilical artery was in normal position.

c) Coronary sinus drainage to the umbilical portion of Left portal vein.

d) Arteriovenous fistula

ABNORMAL STRUCTURE OR CONFIGURATION OF VESSELS

b)Segmental thinning of umbilical cord vessels a) Thormbosis a) ARTERY, B) VEIN.

c) Umbilical cord constriction

INTRINSIC – ABSENCE OF WHARTON’S JELLY

EXRINSIC :- Amniotic bands.

Nuchal loops.

True knots .

Fetal grasping.

Entanglement in monoamniotic twins.

Cord presentation and occult prolapse

NUCHAL CORD :-1) Cord round the neck.

Two types of cord around foetal neck.TYPE A- umbilical cord encircles the fetal neck in a sliding manner (less dangerous)TYPE B- Nuchal cord encircles the neck in a locking manner (very dangerous)

NUCHAL CORD

TYPE ANuchal loop 3600 around the foetal neck where the placental end crosses OVER the foetal end

NUCHAL CORD

TYPE BNuchal loop 3600 around the foetal neck where the placental end crosses UNDER the foetal end.Type A is loose and can undo itself where as Type B locks and cannot undo itself

TIGHT NUCHAL CORDDisruption of the smooth contour of the foetal neck compressing skin in that area.

COLOUR DOPPLER

Tight cord

ARTERIAL :- Increased velocities and systolic Notch.

VENOUS :- Prestenotic dialatation of vein

Umbilical cord abnormalities found in twin gestations are nonspecific and can be found in singleton gestations ( ie, placenta previa, placental abruption , single umbilical artery, velamentous cord insertion , vasa previa etc.) However , other anomalies are unique to twin gestations, and are mainly associated with monoamniotic twins –these include cord entanglement . most of these conditions can be diagnosed with ultrasound.

CORD TO CORD ENTANGLEMENT IN TWIN GESTATIONS

* Uncommon, representing only 4 % of malformation of the umbilical cord (1)* There are types which may / may not be associated with malformation: 1. Intra- abdominal portion of the umbilical vein. ( i.e. intrahepatic or intra – abdominal extrahepatic) 2. Intra- amniotic portion of the umbilical vein.

UMBILICAL VEIN VARIX

* Cystic round or fusiform shaped mass.* Orientated in an anteroposterior, caudocranial direction. * Located within the substance of the liver ( intrahepatic type). * Located directly cephalad to the insertion of the umbilical vein into the fetal abdomen. * Differential diagnosis

* Choledochal cyst* Liver , mesenteric , ovarian or urachal cyst.* cystic lymphangioma

The demonstration of blood flow within the mass on color doppler differentiates the varix from

the above cystic masses.

ULTRASOUND OF INTRA – ABDOMINAL VARIX

* Tortuous cystic varix of umbilical vein* Detection is enhanced by using color doppler imaging. * Complications * Cord thrombosis (may be seen in 1 in 25 autopsies in fetuses with cord abnormalities ) (3) * Hemorrhage through the amniotic sheath with fetal demise.

ULTRASOUND OF INTRA – AMNIOTIC VARIX

Abnormal widening or blood filled buldge.

Aneurysm is large.

Can block the blood vessels of umbilical cord.

Intrauterine growth restriction.

Excessive bleeding.

Fetal mortality

ANEURYSM OF UMBILICAL CORD

KNOTS OF UMBILICAL CORD

KNOTS OF THE CORD

* TRUE KNOT :- When the foetus passes through a loop of the cord. If pulled tight , foetal asphyxia may result.

* FALSE KNOT: Localised collection of Wharton’s jelly containing a loop of umblical vessels.

True knot False knot

TRUE KNOTS :-

Incidence 1-2 % More common in monoamniotic twins. Active foetal movements create true knots. Risk of still births is increased 5 to 10 folds in those with true knots. FHR Abnormalities are common during labor but cord blood PH Values are normal.

TRUE KNOTS OF THE CORD

• Although an abnormal or non – reassuring heart tracing can be indicative of the true knot. • Method of choice for diagnosis of knot, specifically, four dimensional ,colour doppler & power doppler.• When a true knot is diagnosed, strict monitoring of foetal well – being is requied during pregnancy and delivery.

TRUE KNOTS OF THE CORDDIAGNOSING TRUE KNOTS:-

True knot

(True knot , Hypoxic Ischemic Encephalopathy (HIE) and cerebral palsy)

1. Long umbilical cord2. Monoamniotic twin.3. Polyhydramnios.4. Mother is carrying twins, triplets or more.5. Mother more than 35 yrs. 6. Mother smokes or uses drugs.7. Large for gestational age.8. Nutritional deficiencies.

TRUE KNOTS OF THE CORD

INCREASED RISK FACTOR FOR A TRUE KNOT :-

PROLAPSE of umbilical cord into endocervical canal at delivery in 0.5 % cases resulting in perinatal mortality due to cord compression cord presentation in presence of cord between foetus and internal OS.Predisposing factors:-1) Nonvertex foetal lie.2) Polyhydromnios.3) Cephalo pelvic disproportion.4) Multiple gestation.5) Increased cord length.

CORD PROLAPSE AND PRESENTATION

Hemangioma 1. Echogenic structure with demonstrable perfusion

2. Common towards placental end3. Less common – Fetal end of cord vitelline capillaries. D/D – Teratoma Cord haematoma

CORD TUMORS

CORD TUMORS

Angiomyxoma

1. Usually benign .2. Hetrogenous mass

Teratoma -1. Usually benign2. Solid with / without cystic areas3. Contains tissue from all three germ

cells types.4. Calcification.

Hematoma - Most after appears hyperechoic but the echotexture may very depending up on age of haemorrahge. Spontaneous hematomas are usually due to venous source of bleeding related to umbilical cord knot’s or torsions lead to fetal monitoring and possible emergency deliveryinvolve intrafoetal or extrafoetal portion of umbilical vein

CORD TUMORS

Patent urachus is a communication the dome of the bladder and the umbilicus.

PATENT URACHUS

• Also called persistent urachus

• Rare: leads to urination through umbilicus

• May be associated with infections

Aneuploidy is the presence of abnormal number of chromosomes in a cell .whartorn’s jelly in known to influence cell behavior and tissue remodeling especially during embryogenesis. Aneuploid foetuses have thicker umbilical cords can be related to increased amount of wharton’s jelly.

ANEUPLOIDY AND CONGENITAL ANOMALIES

One of the possible cause of increased nuchal translucency in trisomy 21.

True and pseudocysts of the cord have similar appearances; true cysts are usually associated with anomalies of the umbilicus and / or bladder such as omphalocele or patent urachus.

Higher incidence in reduced number of coiling & absent coiling.Velamentous insertion. Short length of cord.Associated and Tumors & cysts.Single umblilical artery – Trisomy – 13.

Trisomy - 18.Persistent right umbilical vein.Umbilical vein Varix.OmphaloceleFour & multiple vessels cord

ANEUPLOIDY AND CONGENITAL ANOMALIES

UMBILICAL ARTERY

NORMAL ABNORMAL

NORMAL UMBILICAL ARTERY

ABNORMAL UMBILICAL ART. DOPPLER WAVEFORM

Umbilical vein doppler patterns are usually evaluated in the intra – abdominal portion of the vein.

The appearance of pulsatile flow in the UV is a simple and reliable marker of circulatory compromise , long recognized as a marker of asphyxia in small – for gestational age foetus.

VENOUS DOPPLER

ABNORMAL DOPPLER WAVEFORM(A)umbilical vein (UV).

(B) ductus venosus

(C ) Inferior vena cava (IVC) .

(B) Normally has forward blood flow throughout the cardiac cycle. In compromised fetuses a drop in arterial systolic forward velocities is observed. As central venous pressure increases, blood flow may be reversed during arterial systole.

ABNORMAL DOPPLER WAVEFORM

(A) Abnormal UV waveform in haemodynamically compromised fetuses is characterized by the appearance of pulsations.

(C) Abnormal IVC waveforms in intrauterine growth restriction show a

decrease in forward flow during the S-wave (S) and D-wave (D) and

accentuation of reversed flow in the A-wave (annotated ‘a’). As the

condition deteriorates the D-wave may be reversed.

ABNORMAL DOPPLER WAVEFORM

EMBRYOLOGY AND ANATOMY

The umbilical cord forms between 5th and 12th week of gestation with contributions from the

1 Body stalk.

2 Omphalomesenteric or vitelline duct.

3 Yolk sac.

4 Allantois.

EMBRYOLOGY AND ANATOMY

REFERENCE : RADIOGRAPHICS 1995 ( RSNA 1995)

TAKE HOME MESSAGE

SINGLE UMBILICAL ARTERY.

VASA PREVIA.

VELAMENTOUS INSERTION.

ABNORMAL UMBILICAL DOPPLER.

CORD ROUND NECK.

CORD PROLAPSE.

DON’T MISS

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