(593) Differences in Neonatal Outcomes Among Isolated and Non-isolated Prenatally Detected Omphaloceles

Objective: An estimated 35-80% of pregnancies with prenatally detected omphaloceles (PDO) have additional anatomic anomalies, referred to as non-isolated omphaloceles. The true prevalence of isolated vs non-isolated omphaloceles remains unclear, as does the risk of perinatal and neonatal death in pregnancies with PDO. This study aimed to evaluate the rate of additional prenatally detected anomalies in pregnancies with PDO and compare neonatal outcomes among isolated and non-isolated PDO, in a modern cohort from a large academic center.

Study Design: This was a retrospective cohort study at a large academic referral center from 2007-2023. All pregnancies with confirmed PDO were included. Maternal demographics & comorbidities, and fetal, perinatal, neonatal, & childhood outcomes were obtained. Pregnancies with isolated omphaloceles were compared to those with non-isolated omphaloceles with isolated defined as having no other major fetal structural abnormalities. The primary outcome was survival at 1 year of age. Bivariate analyses were performed, and logistic regression was used to assess the association of isolated omphalocele with the primary outcome.

Results: 102 pregnancies were included, with n=42 (41.1%) isolated omphaloceles and n=60(58.9%) non-isolated. Baseline demographics and medical histories were similar between the groups. Isolated and non-isolated defect sizes were similar (2.9 ± 1.9 cm vs. 3.8 ± 3.3 cm, p=0.17) (Table). Birthweights and mode of delivery were similar between the groups. Isolated omphaloceles were associated with a significantly lower rate of neonatal death within one year (4.8% vs.  26.7%, aOR (95%CI) 0.17 (0.03-0.88)). Neonates with an isolated omphalocele were also less likely to require intubation (38.1% vs 61.4%, aOR 0.37 (0.15-0.91)). 

Conclusion: In a cohort of prenatally diagnosed omphaloceles, isolated omphaloceles had 5-fold reduced odds of death by 1 year compared to non-isolated omphaloceles. Isolated omphaloceles were also associated with decreased rate of intubation. These data can aid in counseling families with prenatally detected omphaloceles.