OB Unit 6- Fetal Abdomen 24- 38

What are anomalies the liver is also associated with?

• Diaphragmatic hernia

• Omphalocele

The liver is _______ affected by isolated hepatic lesions in utero (parenchymal cysts, hemangiomas, hamartomas have been reported)

Rarely

What are US findings for liver lesions?

• Tumors appear hypoechoic, solid masses within liver, may have cystic components

• ~ 5% are calcified

• If multiple calcifications present? if from infection—- brain & spleen may be affected from infection also

What is Situs Inversus?

•Total reversal of abdominal & thoracic organs

What is Partial reversal?

Mirror image of some organs

What is the mortality rate percentage for partial reversal?

90-95%

What is Situs Inversus associated with?

• Asplenia or Polysplenia

• Cardiac malformations – common (99% in Asplenia; 90% in Polysplenia)

What is Situs inversus also known as?

Heterotaxy Syndrome or Situs Ambiguous

What are the ultrasound findings of total situs?

• Right side – heart, aorta, spleen, stomach

• Left side – liver, GB, IVC

What are the US findings of partial situs?

• Right side – stomach

• Left side – liver

• Dextrocardia – heart on right side of chest with normal stomach position

What are some other anomalies of the hepatobiliary system?

•GI

•GU

•NTD-neural tube defects

What is this image showing?

Partial situs- stomach on right and hypoplastic left heart

What is pseudoascites?

• Sonolucent band near anterior wall in fetus over 18 weeks gestation

• Normal musculature at abd. wall

• Always confined to anterior or anterolateral aspect of fetal abdomen

• NEVER outlines the falciform ligament

What is this image showing?

Pseudoascites

What is True Ascites?

• Is within peritoneal recesses/around organs,

• Moves to more dependent portion of abdomen,

• Outlines falciform ligament

What is this image showing?

True ascites

What pathology can be associated with the gallbladder?

• Cholelithiasis

• Choledochal cyst

  • Dilation of common bile duct

What are the US findings for the GB?

• Cystic mass adjacent to fetal stomach

• **Remember ** GB is more anterior than stomach & on right side of abdomen

• Dif. Dx.: duodenal atresia

What are these images showing?

Cholelithiasis- stones in the GB

What is the criteria for a choledochal cyst?

• Cyst in close proximity to neck of GB

• Oval RUQ cyst with an entering duct

• Cyst & GB may enlarge as pregnancy progresses

• Absence of peristalsis

What are these images showing?

Choledochal cyst

What is Extrahepatic Biliary Atresia

• Blockage of bile ducts due to failure of recanalization after solid stage of development 

With the spleen, what can be identified in utero?

Asplenia 

What may be associated with CHD?

Polysplenia

What is splenomegaly and hepatomegaly associated with?

• Rh immunization disease

• Beckwith-Weidemann Syndrome

What are the causes of not finding anormal stomach?

• Esophageal atresia or Tracheoesophageal fistula

• Diaphragmatic hernia

• Facial cleft

• CNS disorders

• Other swallowing disorders

• May cause Polyhydramnios

• Oligohydramnios from other causes

What is a tracheoesophageal septum?

Separates the esophagus from the trachea

What is esophageal Atresia?

• Abnormal deviation of septum posteriorly

• Commonly with fistula between trachea & esophagus allowing passage of fluid into stomach

• BLOCKAGE

What is esophageal Stenosis?

• Narrowing of esophagus distally

  • Usually distal 1/3

What is this image showing?

Esophageal Atresia

What are the US finding for any esophageal anomalies?

• Polyhydramnios – may not develop until 3^rd trimester

• Absent stomach

  • BUT…50% stomach is visualized due to fistula

• Coexisting anomalies (50-70%)

  • Anorectal atresia

  • VACTERL

• Growth restriction (40% of cases)

• Chromosomal trisomies 18 & 20

What is the term Vacteral?

Trachea and esophagus anomalies

The stomach is a fluid-filled structure in the LUQ and should be seen between what weeks?

14-16 weeks

What should the fluid look like in the stomach?

• Fluid should be anechoic

  • Echogenic debris may sometimes be seen along dependent wall

    • Vernix, protein, intraamniotic hemorrhage