A UCLA Health research team has identified and described a rare type of bowel obstruction in premature infants, called meconium-related obstruction of prematurity (MROP). This condition is different from other known neonatal obstructions such as Hirschsprung disease and meconium ileus associated with cystic fibrosis. MROP had not been well documented in medical literature until recent studies.
Researchers used retrospective reviews, national database analyses, and collaborations among multiple institutions to study the condition. They found that premature infants diagnosed with MROP are more likely to need surgery, experience longer hospital stays, and face higher health care costs compared to other newborns.
The findings have been presented at several international conferences, including the Pacific Association of Pediatric Surgeons meetings in 2023 and 2024, the Association for Academic Surgery Academic Surgical Congress in 2025, and the American Pediatric Surgical Association meeting in 2025. Results have also been published or are pending publication.
MROP occurs when thick meconium blocks the intestines of premature babies. According to UCLA researchers, this form of obstruction appears specifically linked to prematurity due to factors such as poor gut motility, thickened meconium, and weaker abdominal muscles. The importance of recognizing MROP is increasing as rates of premature birth rise and survival improves for extremely preterm infants.
The research began with clinical observations at UCLA Health and included a review of past cases. Investigators partnered with organizations to analyze data from the National Inpatient Sample, which is the largest publicly available database on hospital discharges in the United States. The study expanded through collaboration with the University of California Fetal Care Consortium, allowing UC medical campuses to share expertise in neonatal surgery. Analysis confirmed that greater degrees of prematurity were strongly associated with an increased likelihood of needing surgical intervention for MROP.
By better defining MROP and its risks, UCLA surgeons and their collaborators aim to develop quality improvement strategies focused on prevention and management. Their goal is to improve outcomes for premature infants affected by this condition and inform broader care approaches for children with gastrointestinal disorders.
“This work shows how careful clinical observation, coupled with large-scale data analysis and collaboration across institutions, can directly translate into improved care for newborns,” said , pediatric surgeon and clinical professor at UCLA.
The authors include Daniel DeUgarte, MD; Jordan Rook, MD, PhD; members from UCLA CORELAB; and collaborators from the University of California Fetal Care Consortium.
