Timing a high-risk delivery can be a delicate balance. That's particularly true for gastroschisis, a congenital disorder in which some organs, most commonly the intestines, develop outside the abdominal wall.
Identifying prenatal ultrasound findings associated with the risk of poor gastroschisis outcomes
In close to 90% of cases, patients are born without complications and cured with a relatively low-risk surgery. The other 10% of cases, however, can become life-threatening in the second trimester.
Fetal surgeon Kenneth Liechty, MD, and his team at the Colorado Fetal Care Center at Children's Hospital Colorado, recently shed light on a predictive factor for complex cases of gastroschisis.
In 4.9 of 10,000 U.S. births
Cost of complex gastroschisis per patient for a hospital stay
Revealing the dilation correlation for gastroschisis
Dr. Liechty had speculated for some time that bowel dilation might correlate with complexity. If the opening in the abdominal wall constricted the intestines, he reasoned, the resulting blockage and buildup of fluid might lead to bowel dilation, either externally or internally.
Previous studies, however, had not revealed such a correlation.
- ICD diagnosis code of gastroschisis
- Admitted to a free-standing children's hospital with a Level 3 NICU between 2007 and 2017
- No missing ultrasound report or images
"I think the difference between previous studies and this one is really the rigor involved," says Dr. Liechty. "This wasn't just one sampling. We followed 55 patients over time, looking at about a dozen different variables."
One of those variables was distinguishing between extra-abdominal and intra-abdominal intestinal diameter. That turned out to be key. An intra-abdominal diameter of more than 17mm correctly identified 75% of complex cases. The negative correlation was even stronger, with an intra-abdominal diameter of less than 17mm identifying 92% of "simple" cases.
"There may be other factors involved," says Dr. Liechty. "There may be inflammatory processes; the bowel being exposed to amniotic fluid may lead to progressive bowel damage. So if these predictive factors are pointing to a poor outcome, it may be better to deliver earlier and decrease the duration of those insults."
- Compared to simple gastroschisis, complex gastroschisis had higher IAID, fetal AC, amniotic fluid index and bowel wall thickening. Not other differences were significant between the two groups.
- IAID was the only ultrasound finding with a strong enough relationship with patient outcomes to be determined predictive.
- Larger IAIDs were associated with a 20% increased chance of a complex diagnosis and longer time to full enteral feeding.
- A 17mm IAID at 32 weeks gestational age reliably distinguishes between complex and simple cases of gastroschisis.
Based on the study's findings, IAID is associated with a longer time to full enteral feeding and the diagnosis of complex gastroschisis. Examination of Prenatal Sonographic Findings: Intra-Abdominal Bowel Dilation Predicts Poor Gastroschisis Outcomes was published in the August 2019 issue of Fetal Diagnosis and Therapy.