What is the fate of abnormal looking bowel seen on prenatal ultrasound?

While reviewing the literature on prenatal imaging and their prognostic implications, I came across this relevant article by Ruiz et al from Morgan Stanley Children's Hospital.

The authors looked to study the relationship between abnormal prenatal ultrasound findings in the bowel and the presence of an actual bowel abnormality at birth.  They divided patients into two groups, those with hyperechogenic bowel and those with dilated bowel.

Of the fetuses with a finding of hyperechogenic bowel, the authors noted a 20% rate of prenatal demise.  Otherwise, only 10% of those patients were born with abnormal bowel (usually from meconium disease).  During follow up prenatal ultrasound studies, 65% of the findings resolved in that group of patients.

The group with the dilated bowel on u/s had a higher chance of having a true bowel abnormality when born.  Although the rate of prenatal demise in that group was lower (10%), fetuses with dilated loops of bowel on prenatal u/s had a 53% chance of being born with abnormal bowel (usually from intestinal atresia).  On follow up prenatal ultrasound studies, only 20% of the findings resolved in that group of patients.

This data sheds some light on the significance of bowel abnormalities found on prenatal ultrasounds, and thus helps better counsel parents on what to expect.

Reference:

Ruiz JR et al.  Neonatal outcomes associated with intestinal abnormalities diagnosed by fetal ultrasound.  Journal of Pediatric Surgery (2009) 44,71