Predicting neonatal mortality prior to discharge from hospital in prenatally diagnosed left congenital diaphragmatic hernia

Abstract

Objectives: To evaluate the association of standardized prenatal imaging parameters and immediate neonatal variables with mortality prior to discharge in infants with isolated left congenital diaphragmatic hernia (LCDH), and to compare the performance of ultrasound- and magnetic resonance imaging (MRI)-based severity grading for the prediction of neonatal mortality.

Methods: This was a retrospective study of infants with prenatally diagnosed isolated LCDH referred to a single tertiary center between 2008 and 2020. Fetuses with right or bilateral congenital diaphragmatic hernia, additional major structural anomaly or known genetic condition, as well as cases that underwent fetal intervention or declined postnatal intervention, were excluded. Ultrasound and MRI images were reviewed retrospectively. Univariable and multivariable analyses were performed, incorporating prenatal and immediate neonatal factors to analyze the association with neonatal mortality prior to discharge, and a prediction calculator was generated. The performance of ultrasound and that of MRI for the prediction of neonatal mortality were compared.

Results: Of 253 pregnancies with fetal CDH, 104 met the inclusion criteria, of whom 77 (74%) neonates survived to discharge. Seventy-five fetuses underwent both prenatal ultrasound and MRI. On multivariable analysis, observed/expected (o/e) lung-to-head ratio and o/e total fetal lung volume were associated independently with neonatal death (adjusted odds ratio, 0.89 (95% CI, 0.83-0.95) and 0.90 (95% CI, 0.84-0.97), respectively), whereas liver position was not. There was no significant difference in predictive performance between using ultrasound and MRI together (area under the receiver-operating-characteristics curve (AUC), 0.85 (95% CI, 0.76-0.93)) compared with using ultrasound alone (AUC, 0.81 (95% CI, 0.72-0.90); P = 0.19). The addition of neonatal parameters (gestational age at birth and small-for-gestational age) did not improve model performance (AUC, 0.87 (95% CI, 0.80-0.95)) compared with the combined ultrasound and MRI model (P = 0.22). There was poor agreement between severity assessment on ultrasound and MRI (Cohen's κ, 0.19). Most discrepancies were seen among cases deemed to be non-severe on ultrasound and severe on MRI, and outcomes were more consistent with MRI-based prognostication.

Conclusions: In fetuses with prenatally diagnosed isolated LCDH, mortality prediction using standardized ultrasound and MRI measurements performed reasonably well. In cases classified as non-severe on ultrasound, MRI is recommended, as it may provide more accurate prognostication and assist in the determination of candidacy for fetal intervention. © 2024 The Author(s). Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Keywords: CDH; MRI; congenital diaphragmatic hernia; magnetic resonance imaging; neonatal mortality; ultrasound.

Figure 1

Flowchart summarizing inclusion in study of expectantly managed pregnancies with isolated left congenital diaphragmatic hernia (CDH). *Some cases had more than one reason for exclusion. CMA, chromosomal microarray; FETO, fetal endoscopic tracheal occlusion; QF‐PCR, quantitative fluorescence polymerase chain reaction; WES, whole‐exome sequencing.

Figure 2

Receiver‐operating‐characteristics curves showing performance of ultrasound parameters, magnetic resonance imaging (MRI) parameters and perinatal factors in predicting neonatal death prior to discharge in isolated left congenital diaphragmatic hernia. , ultrasound‐only model (includes gestational age (GA) at diagnosis, observed/expected (o/e) lung‐to‐head ratio, intrathoracic posterior/retrocardiac stomach position, female sex and polyhydramnios); , MRI‐only model (includes GA at diagnosis, o/e total fetal lung volume, intrathoracic liver location and female sex); , ultrasound + MRI model (includes all variables from ultrasound‐only model and MRI‐only model); , ultrasound + MRI + immediate neonatal factors model (includes all variables from ultrasound + MRI model plus small‐for‐gestational age and GA at delivery < 37 weeks).

Figure 3

Neonatal mortality rates in 75 cases of isolated left congenital diaphragmatic hernia with concordant or discordant prediction of severe pulmonary hypoplasia on ultrasound (US) (observed/expected lung‐to‐head ratio ≤ 25% (US ≤ 25) or > 25% (US > 25)) and magnetic resonance imaging (MRI) (observed/expected total fetal lung volume ≤ 35% (MRI ≤ 35) or > 35% (MRI > 35)). *P = 0.009.