Dynamic discriminant model for predicting respiratory distress at birth based on mass volume ratio in fetuses with congenital lung malformation

Serial lung mass volume ratios as prognostic indicators of neonatal respiratory morbidity in fetal pulmonary malformations

BACKGROUND

Several studies have shown that the congenital pulmonary airway malformation volume ratio is a useful prognosticator of neonatal outcome in prenatally diagnosed lung lesions. However, there remains a lack of consensus on which congenital pulmonary airway malformation volume ratio values have the best predictive value because of operator dependence, inherent changes in lung lesion size throughout gestation, and the widespread use of maternal steroids.

OBJECTIVE

This study sought to determine the association between serial congenital pulmonary airway malformation volume ratio measurements and neonatal outcomes among fetuses with lung malformations.

STUDY DESIGN

This was a retrospective cohort study of fetuses with a prenatally diagnosed lung malformation managed at 2 major fetal centers from January 2010 to December 2021. Prenatal variables, including prospectively measured congenital pulmonary airway malformation volume ratio measurements (initial, maximum, and final), were analyzed. The results were correlated with 3 outcome measures, namely surgical resection before 30 days of life, a need for supplemental O2 at birth, and endotracheal intubation at birth. Statistical analyses were performed using receiver operating characteristic curve analyses, Welch 2 sample t tests, and multivariable logistic regressions (P<.05).

RESULTS

There were 123 fetuses with isolated lung lesions identified. Eight (6.5%) had hydrops. The mean initial congenital pulmonary airway malformation volume ratio was 0.67±0.61 cm2 at 22.9±3.9 weeks' gestation. The mean maximum congenital pulmonary airway malformation volume ratio was 1.08 ± 0.94 cm2 at 27.0 ± 4.0 weeks' gestation. The mean final congenital pulmonary airway malformation volume ratio was 0.58±0.60 cm2 at 33.2±4.1 weeks' gestation. At a mean gestational age at delivery of 38.3±2.6 weeks, 15 (12.2%) underwent neonatal lung resection for symptomatic disease. In a multivariable regression, all 3 congenital pulmonary airway malformation volume ratio measurements showed a significant correlation with neonatal lung resection (P<.001). Optimal congenital pulmonary airway malformation volume ratio cutoffs were established based on an initial congenital pulmonary airway malformation volume ratio of ≥0.8 cm2, maximum congenital pulmonary airway malformation volume ratio of ≥1.5 cm2, and a final congenital pulmonary airway malformation volume ratio of ≥1.3 cm2 with associated areas under the curve of 0.89, 0.97, and 0.93, respectively. The final congenital pulmonary airway malformation volume ratio had the highest specificity for predicting surgical lung resection in the early postnatal period.

CONCLUSION

Measuring congenital pulmonary airway malformation volume ratios throughout pregnancy in fetuses with pulmonary malformations has clinical value for prenatal counseling and planning care transition after delivery. Fetuses with a final congenital pulmonary airway malformation volume ratio of more than 1.3 cm2 are likely to require neonatal surgery and therefore should be delivered at tertiary care centers with a neonatal intensive care unit and pediatric surgical expertise.

Impact of prenatal estimation of the risk of respiratory distress in neonates with congenital pulmonary malformations on the choice of delivery site

BACKGROUND

The vast majority of prenatally diagnosed congenital pulmonary malformations (CPM) remain asymptomatic at birth. The maximal value of the CPM volume ratio (CVRmax) predicts the risk of neonatal respiratory distress (NRD), and should allow for better assessment of the level of expertise needed at the delivery site.

AIM

This study evaluated the level of maternity units currently chosen for the delivery of CPMs, and determined the impact of the choice of delivery site based on the CVRmax, with a threshold of 0.4 cm².

METHODS

Data were extracted from the French prospective MALFPULM cohort, with inclusion between March 2015 and June 2018.

RESULTS

The final study population consisted of 383 women. Deliveries in level 1 or 2 maternity units (n = 98, 25%) involved CPMs with lower CVRmax (p<0.001), causing fewer signs of prenatal compression (p = 0.025). Among the 62 children (16%) who presented with NRD, only seven (11%) were born in level 1 or 2 units (p = 0.0078). Choosing the maternity level according to the CVRmax would have increased the number of births in level 1 or 2 maternity hospitals by 70%. In these maternity units, the percentage of children with NRD would have increased from 8% in the actual distribution to 10% in the new strategy.

CONCLUSION

Our results showed an overuse of level 3 maternity hospitals for the delivery of newborns with a prenatal diagnosis of CPM. The use of CVRmax should enable a reduction in the use of expertise centers without an adverse impact on newborns.

Prenatal ultrasound-and MRI-based imaging predictors of respiratory symptoms at birth for congenital lung malformations

BACKGROUND

Congenital lung malformations (CLM) are rare developmental anomalies of the fetal lung with a minority of patients exhibiting symptoms around the time of birth. Although ultrasound remains the gold standard, fetal MRI has recently been incorporated as an adjunct imaging modality in the workup and prenatal counseling of patients with CLM as it is thought to more accurately delineate lesion boundaries and diagnose lesion type. We evaluate what prenatal variables correlate with postnatal respiratory symptoms.

METHODS

We performed a retrospective review of patients with prenatal diagnosis of CLM treated at our institution between 2006-2020. Fetal ultrasound and magnetic resonance imaging (MRI) parameters including maximal congenital pulmonary airway malformation volume ratio (CVR), absolute cyst volume, and observed to expected normal fetal lung volume (O/E NFLV) were correlated with outcomes including postnatal respiratory symptoms, need for supplementary oxygen or mechanical ventilation, delay in tolerating full feeds, resection in the neonatal period.

RESULTS

Our study included 111 patients, all of whom underwent fetal ultrasound with 64 patients additionally undergoing fetal MRI. Postnatal respiratory symptoms were noted in 22.5% of patients, 19.8% required supplemental oxygen, 2.7% mechanical ventilation and two patients requiring urgent resection. Ultrasound parameters including absolute cyst volume and maximal CVR correlated with need for mechanical ventilation (p=0.034 and p=0.024, respectively) and for urgent resection (p=0.018 and p=0.023, respectively) and had a marginal association with postnatal respiratory symptoms (p=0.050 and p=0.052). Absolute cyst volume became associated with postnatal respiratory symptoms (p=0.017) after multivariable analysis controlling for maternal steroid administration and gestational age. O/E NFLV did not correlate with perinatal outcomes.

CONCLUSION

We have found that ultrasound-based measurements correlate with postnatal respiratory symptoms, while MRI derived O/E NFLV does not. Further studies are needed to elucidate the role of MRI in the prenatal workup of congenital lung malformations.

TYPE OF STUDY

Study of Diagnostic Test.

LEVEL OF EVIDENCE

Level I.

Predicting the risk of respiratory distress in newborns with congenital pulmonary malformations

OBJECTIVES

Most children with prenatally diagnosed congenital pulmonary malformations (CPM) are asymptomatic at birth. We aimed to develop a parsimonious prognostic model for predicting the risk of neonatal respiratory distress (NRD) in preterm and term infants with CPM, based on the prenatal attributes of the malformation.

METHODS

MALFPULM is a prospective population-based nationally representative cohort including 436 pregnant women. The main predictive variable was the CPM volume ratio (CVR) measured at diagnosis (CVR first) and the highest CVR measured (CVR max). Separate models were estimated for preterm and term infants and were validated by bootstrapping.

RESULTS

In total, 67 of the 383 neonates studied (17%) had NRD. For infants born at term (>37 weeks, N=351), the most parsimonious model included CVR max as the only predictive variable (ROC area: 0.70±0.04, negative predictive value: 0.91). The probability of NRD increased linearly with increasing CVR max and remained below 10% for CVR max<0.4. In preterm infants (N=32), both CVR max and gestational age were important predictors of the risk of NRD (ROC area: 0.85±0.07). Models based on CVR first had a similar predictive ability.

CONCLUSIONS

Predictive models based exclusively on CVR measurements had a high negative predictive value in infants born at term. Our study results could contribute to the individualised general risk assessment to guide decisions about the need for newborns with prenatally diagnosed CPM to be delivered at specialised centers.