P1.189: Transport characteristics for preterm versus term infants with congenital diaphragmatic hernia

Background: Preterm infants (born < 37 completed weeks of gestation) with congenital diaphragmatic hernia (CDH) may be at a higher risk for transport decompensation compared to term infants with CDH. At our institution, all infants with prenatally diagnosed CDH are transported from the delivery hospital to our children’s hospital with a surgical Level IV neonatal intensive care unit (NICU). The urgency of transfer is based on predicted CDH severity using observed-to-expected total fetal lung volume (O/E TFLV) and lung-to-head ratio (O/E LHR). Our objective was to compare early postnatal transport stability for preterm versus term infants with CDH.

Methods: We conducted a retrospective observational pilot study of infants with prenatally diagnosed CDH transported by our pediatric critical care transport team between a single referring and receiving facility from 2020-2024. Chart-based demographic and clinical data was abstracted. Infants were characterized based on predicted CDH severity using O/E TFLV or O/E LHR; mild (≥35%), moderate (25-34%), and severe ( < 25%). Vital sign abnormalities were defined using gestational age adjusted clinical standards. The primary outcomes were the intra-transport vital sign abnormality rate and the timing of transport milestones. Kruskal-Wallis or Fisher’s exact tests were used to compare clinical characteristics and vital sign abnormalities across preterm and term infants.

Results: 51 infants were included; 40 (78%) term and 11 (22%) preterm. There was no difference in predicted CDH severity between groups (Table 1). Significantly more preterm infants had cardiac (45% vs 13%, p=0.03) and other congenital anomalies (82% vs 43%, p=0.04) compared to term infants. There was no difference in extracorporeal membrane oxygenation (ECMO) use, survival to discharge, or hospital days between the groups (Table 1). More preterm infants received vasopressors on transport compared to term infants (36% vs 3%, p=0.006). Other transport interventions including respiratory support were not significantly different between the groups. The total time from birth to transfer of care at the receiving facility was significantly shorter for preterm infants (66min [57-183] vs 156min [80-216], p=0.04). Many abnormal vital signs were seen during transport in both groups, with no statistically significant differences between them (Table 2).

Conclusion: The total time from birth to transfer of care at the receiving hospital was faster for preterm compared to term infants with CDH, but the timing of other transport milestones was similar. Preterm infants received more vasopressor support during transport, suggesting more hemodynamic instability, though infants in both groups had similar rates of abnormal vital signs. Although this study is limited due to the small number of preterm infants included and overall short transport times, these findings may help transport teams better prepare to care for preterm infants with CDH.