Videos 3, 4 and 5: demonstrate the dilated loops of intestine and polyhydramnios.

Videos 6 and 7: show movements of the meconium inside the intestine due to the evident peristalsis of the intestinal loops.

Image 1 and video 8: show the polyhydramnios and the chorio-amniotic separation.

Videos 9, 10 and 11: demonstrate the mild hydronephrosis and the normal urinary bladder.

Images 2 and 3: tomographic ultrasound imaging technique clearly showing the extent of the dilatation of intestinal loops.

Videos 12-15: cine calc with inversion mode showing the dilated intestinal loops.

Video 16: Shows the subjectively dilated stomach (central structure) by inversion mode.

Images 4-10: The dilation of the intestinal loops is demonstrated by different volumetric ultrasound rendering algorithms. This dilatation has been demonstrated by surface rendering which is clearly showing the intestinal walls and the meconium inside (image 4), by inversion mode (image 5), by high definition (image 6), by high definition with inversion mode (image 7), by silhouette with different transparency settings (images 8 and 9) and by SonoAVC (image 10)

Jejunum and ileum are frequent sites of intestinal atresia which in turn is a common cause of congenital obstruction of bowel ^1,2. The prenatal ultrasonographic characteristics of intestinal obstruction include fetal echogenic bowel, enlarged gastric bubble, dilated intestinal loops and polyhydramnios ordered chronologically according to the timing of occurrence ¹. Abdominal cyst is another sonographic finding in bowel obstruction ¹. It is note worthy that jejunal atresia is more amenable to prenatal sonographic diagnosis more than ileal atresia as the later usually does not demonstrate neither enlarged stomach nor polyhydramnios ^1,2. A 15 mm of length and 7 mm of width represent the cutoff values needed to diagnose intestinal dilatation 2. Several mechanisms have been proposed with interruption of blood flow to mesentry at an early stage of development representing the most likely mechanism ^1,2. Efficient gastric peristalsis starts at about 24 weeks thus dilatation of the intestinal loops is usually evident in the 3rd trimester which is the time necessary for the meconium to fill and accumulate inside the intestinal loops ². Obstruction of the colon does not usually result in bowel loops dilatation2. Small bowel atresia is not usually associated with aneuploidy2. Complications of intestinal atresia include perforation, meconium peritonitis and pseudocyst². Prenatal ultrasound detection of non-duodenal small bowel atresia is extremely variable and the overall prediction is close to 50% and is better for jejunal more than ileal atresia³. The prognosis is usually good after surgical correction with low mortality rate but with unnegligible morbidities1,3. Prenatal diagnosis of non-duodenal small bowel atresia has a positive impact on the prognosis as it allows for prompt postnatal management and thus decreasing complications^2,3. Prenatal diagnosis is not linked to an increase neither in hospital stay nor TPN days as previously reported ¹.

References

1. Wax JR, Hamilton T, Cartin A, Dudley J, Pinette MG, Blackstone J. Congenital jejunal and ileal atresia. J Ultrasound Med 2006; 25:337-342

2. Silva P, Reis F, Alves P, Farinha L,  Gomes MS, Camara P. Fetal bowel diltation: a sonographic sign of uncertain prognosis. Case Rep Obstet Gynecol 2015; 2015:608787. doi:10.1155/2015/608787. Epub 2015 Dec 24

3. Virgone C, D'antonio F, Khalil A, Jonh R, Manzoli L, Giuliani S. Accuracy of prenatal ultrasound in detecting jejunal and ileal atresia: systematic review and meta-analysis. Ultrasound Obstet Gynecol 2015; 45: 523-529