OB2 Fetal Abdomen Ch 63 (copy)

what are the fetal abdominal organs

liver, biliary system, spleen, stomach, kidneys, colon

when does the primitive gut form

4th week, dorsal part of YS

what 3 things does the primitive gut form into

foregut, midgut, hindgut

what does foregut develop into

pharynx, lower respiratory, esophagus, stomach, part of duodenum, liver, biliary apparatus, pancreas

what is it called when there is abnormal development of tracheoesophageal septum (does not separate into respiratory and digestive components) that can lead to hydramnios

esophageal atresia

what is the epiploic foramen

small opening that allows lesser sac and peritoneal cavity to communicate

what supplies blood to duodenum

celiac trunk and SMA

when is the duodenum usually recanalized by

end of 8th week

what happens if duodenum does not recanalaize by end of 8th week

duodenal atresia or duodenal stenosis

when does hemopoiesis begin

6th week

what does midgut develop into

small intestines (including most of duodenum), cecum, cloaca exstrophy, ascending and most of transverse colon

what supplies the midgut organs

SMA

what are two common conditions that occur w/malformation of midgut

omphalocele and gastroschisis

what is the most common malformation of midgut

Mekel’s diverticulum

what is Mekel’s diverticulum

when remnant of prox part of yolk stalk doesn’t completely degenerate (finger-like sac that projects from border of ileum)

what does hindgut develop into

left trans colon, descending colon, sigmoid, rectum, some anal canal, bladder, urethra

what supplies blood to hindgut organs

IMA

what week should you see fluid in stomach

>14-16 weeks

what might echogenic debris in the dependent fetal wall of stomach be

vernix, protein, intraamniotic hemorrhage

what are the hypoechoic echos in bowel that may be seen

meconium

where is abdominal circumference measured

PV, UV - portal sinus and umbilical portion of left portal vein

what does the collapsed umbilical vein become after birth

ligamentum teres

when does bowel movement begin

4-5th month

when can peristalsis be seen

after 27th week

how can you differentiate hernia from omphalocele

hernia is covered by subcutaneous tissue and skin

if you don’t see stomach, what should you look for

swallowing disorder, obstruction

what is sono of esophagus

2 or more echogenic parallel lines in thorax (2-3rd trimester)

be sure to see WHAT on both sides of UC insertion points

skin line

what distinguishes colon from small intestine

haustral folds in colon, colon does not have peristalsis

what is normal diameter of small bowel lumen

<= 5 mm

what is normal diameter of colon

14-18 mm at term

when can GB be seen

after 20 Gest weeks

what is most common symptomatic, vascular hepatic tumor of infancy

hemangioendothelioma

what might a hemangioendothelioma cause

hydrops

sono of hemangioendothelioma

hypoechoic solid masses within liver (may have cystic components)

which lobe of liver is larger in utero

left

sono of fetal spleen

homogenous, similar to kidney, slightly less than liver

what are 2 combinations of details of partial situs inversus

thoracic viscera reversed w/ possible abdominal organ reversal or abdominal organs only without heart involvement

what is partial situs inversus divided into

asplenia and polysplenia

what is mortality rate for fetal partial situs inversus

90-95% w/asplenia and 80% w/polysplenia

What is common w/partial situs inversus (more common w/asplenia)

Cardiac malformations

sono of psuedoascites

sonolucent band on anterior or anterolateral ab wall (real ascites seen in recesses too)

where is choledochal cyst located

close to neck of GB, connects to adjacent bile duct

why do atresias (atretic) develop

when portion of bowel grows and infarcts

what accompanies GI atresias

polyhydramnios

what is most common form of esophageal atresia in conjuction with

w/fistula communicating between trachea and esophagus so AF can get by

what is most common coexisting anomaly associated with esophageal atresia

anorectal atresia

what combination is a good indicator of esophageal atresia

polyhydramnios and absent stomach

what is most common form of esophageal atresia

Gross Type C

how common is esophageal atresia

1:2500 live births

what is VACTREL

coexisting anomalies w/esophageal atresia

what does VACTREL stand for

V-vertebral defects, A-anal atresia, C-cardiac defects, T-tracheo-esophageal fistula, R-renal anomalies, E-esophageal atresia, L-limb abnormalities

what is duodenal atresia

blockage of duodenal lument by membrane that prohibits AF passage

what is sono sign of duodenal atresia

double bubble - stomach and duodenum

what trisomy is common w/duodenal atresia

21 (30%)

other anamolies occur in __% of duodenal atresia

50%

what is almost always seen w/duodenal atresia

hydramnios

— in — live births have intestinal obstruction (stenosis of jejunum, ileum)

1:3000-5000

systemic growth restrictions are WHAT with duodenal atresia?

Common

sono of intestinal obstruction

multiple cystic strutures in bowel loops

when is meconium present in bowel

2nd trimester

what is earliest sign of cystic fibrosis

maconium ileus

what is meconem ileus 

small bowel disorder w/thick meconium in distal ileum

what are 3 most common form of bowel obstruction

atresia, malrotation, meconium ileus

normal small bowel may be echogenic in 2nd trimester

True

what is Hirschsprung disease

megacolon - abnormal innervation of large intestine