Growth Patterns of Fetal Lung Volumes in Healthy Fetuses and Fetuses With Isolated Left-Sided Congenital Diaphragmatic Hernia

Does Prediction of Neonatal Mortality by the Observed/Expected Lung-To-Head Ratio Change during Pregnancy in Fetuses with Left Congenital Diaphragmatic Hernia?

INTRODUCTION

The aim of this study was to evaluate prediction of neonatal mortality in fetuses with isolated left congenital diaphragmatic hernia (CDH) when the observed/expected lung-to-head ratio (O/E LHR) was estimated at two different gestational time points during pregnancy.

METHODS

Forty-four (44) fetuses with isolated left CDH were included. O/E LHR was estimated at the time of referral (first scan) and before delivery (last scan). The main outcome was neonatal death due to respiratory complications.

RESULTS

There were 10/44 (22.7%) perinatal deaths. The areas under (AU) the ROC curves were: first scan, 0.76, best O/E LHR cut-off 35.5% with 76% sensitivity and 70% specificity; last scan, AU-ROC 0.79, best O/E LHR cut-off 35.2%, with 79.0% sensitivity and 80% specificity. Considering an O/E LHR cut-off ≤35% to define high-risk fetuses at any examination, prediction for perinatal mortality showed: 80% sensitivity, 73.5% specificity, 47.1% positive and 92.6% negative predictive values, and 3.02 (95% CI 1.59-5.73) positive and 0.27 (95% CI 0.08-0.96) negative likelihood ratios. Prediction was similar in the two evaluations as 16/21 (76.2%) of fetuses considered at risk had an O/E LHR ≤35% in the two examinations; in the remaining 5 cases, two were identified only in the first and three only in the last scan.

CONCLUSION

The O/E LHR is a good predictor of perinatal death in fetuses with left isolated CDH. Approximately 80% of fetuses at risk of perinatal death can be identified with an O/E LHR ≤35%, and 90% of them will have similar O/E LHR values at the first and at the last ultrasound examinations prior to delivery. In general, 88.6% of all CDH fetuses have a similar severity classification based on the O/E LHR at the first diagnostic ultrasound or at the ultrasound examination prior to delivery.

Magnetic Resonance Prediction of Lung Maturity in Fetuses With Congenital Diaphragmatic Hernia

ABSTRACT

To determine if lung to liver MR T2 signal ratio is predictive of neonatal outcome in fetuses with congenital diaphragmatic hernia (CDH).After Interal Review Board approval, the PACS systems at the University of Washington and University of Utah were searched for cases having an in utero fetal MR examination diagnostic of CDH. Inclusion criteria were at least 1 prior ultrasound demonstrating a CDH and an MR obtained within 1 week of that prior ultrasound.A total of 69 patients from the University of Utah and 13 from the University of Washington satisfied the inclusion criteria for a total of 82. After adjusting for gestational age and contralateral lung volume, there was little apparent association between contralateral lung to liver MR T2 signal and 5-minute Apgar score and neonatal mortality When considering neonatal Apgar and mortality, increasing contralateral lung volume was significantly associated with lower risk (hazard ratio, 0.40 per doubling; 95% confidence interval, 0.24-0.69; P = 0.001) as expected.Our data demonstrate that the lung to liver MR signal ratio was not predictive of outcome. The measurement of contralateral lung area, and gestational age at the time of the examination (time of diagnosis) are still the best predictors of poor neonatal outcome.

Do Serial Sonographic Assessments of Fetuses with Isolated Congenital Diaphragmatic Hernia Help Us Predict Survival?

OBJECTIVE

The aim of this study was to assess the ability of serial prenatal sonographic measurements, and specifically changes in the observed-to-expected lung-to-head ratio (O/E LHR) throughout gestation and to predict survival in congenital diaphragmatic hernia (CDH).

METHODS

Retrospective study of CDH fetuses evaluated prenatally and treated postnatally in a single tertiary center, 2008-2020. Sonographic evaluations included side of herniation, liver involvement, and O/E LHR. All data were calculated to assess ability to predict survival.

RESULTS

Overall, 94 fetuses were evaluated prenatally and delivered in our medical center. Among them, 75 had isolated CDH and 19 nonisolated. CDH was categorized as left (n = 76; 80.8%), right (n = 16; 17.0%), or bilateral (n = 2; 2.2%). Overall perinatal survival rate was 57% for all live-born infants, 68% in isolated CDH, and 40% in nonisolated (excluding 2 cases that underwent fetoscopic endoluminal tracheal occlusion and did not survive). The O/E LHR was lower in cases with perinatal death compared to survivors. In cases with multiple evaluations, the minimal O/E LHR was the most accurate predictor of survival and need for perinatal extracorporeal membrane oxygenation (ECMO) support. This remained significant when excluding twin pregnancies or when evaluating only isolated left CDH. In addition to disease severity, the side of herniation and liver position was associated with preoperative mortality.

CONCLUSION

O/E LHR is associated with perinatal survival. In cases with multiple evaluations, the minimal O/E LHR is the most accurate and significant predictor of perinatal mortality and need for ECMO support.

Frontal lobe growth is impaired in fetuses with congenital heart disease

OBJECTIVES

The primary objective of this study was to assess whether fetuses with congenital heart disease (CHD) have smaller frontal brain areas compared with normal controls. The secondary objective was to evaluate whether there are any differences in frontal brain area between cases with different types of CHD, grouped according to their impact on hemodynamics.

METHODS

This was a retrospective cross-sectional study, including 421 normal fetuses and 101 fetuses with isolated CHD evaluated between 20 and 39 gestational weeks at our fetal medicine and surgery unit in the period January 2016-December 2019. The study group was subdivided, according to the CHD hemodynamics, as follows: (1) hypoplastic left heart syndrome and other forms of functionally univentricular heart defect; (2) transposition of the great arteries; (3) conotruncal defects and other CHDs with large shunts; (4) right ventricular outflow tract obstruction, without a hypoplastic right ventricle; (5) left outflow tract obstruction; (6) others. The transventricular axial view of the fetal head was used as the reference view, on which the frontal lobe anteroposterior diameter (FAPD) and the occipitofrontal diameter (OFD) were measured, assuming the former to be representative of the area of the frontal lobes. The FAPD/OFD ratio was then calculated as FAPD/OFD × 100. These two variables (FAPD and FAPD/OFD ratio) were then evaluated and compared between the study and control groups. Adjustment for gestational age, both via multiple linear regression and by using a-posteriori matching based on the propensity score, was employed.

RESULTS

In normal fetuses, FAPD showed a linear positive correlation with gestational age. In fetuses with CHD, the FAPD was shorter than in normal fetuses from the 20^th  gestational week onwards, with the difference increasing after 30 gestational weeks. FAPD/OFD ratio was significantly smaller in fetuses with CHD than in normal fetuses (P < 0.0001) at all gestational ages, with no apparent differences among the various CHD categories, all of which had smaller FAPD/OFD ratio compared with controls.

CONCLUSIONS

Fetuses with CHD have a shorter FAPD and a smaller FAPD/OFD ratio compared with normal fetuses. This impaired growth of the frontal area of the brain seems to occur in all types of CHD, regardless of their impact on hemodynamics. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

The quantitative lung index: the left lung

OBJECTIVE

We have previously described a gestational age-independent sonographic parameter to assess fetal lung growth in the right lung (right quantitative lung index, or QLI-R). The purpose of this study was to develop a similar sonographic parameter to assess the growth of the left lung in the fetus, independent of gestational age, or QLI-L.

STUDY DESIGN

A new index, the QLI-L was derived using published formulas for the head circumference (HC) and the area of the base of the left lung (LA), with the corresponding percentiles.

RESULTS

Left lung growth can be expressed using the following formula: QLI-L=LAL(HC12)2. The 50th percentile of the QLI-L remained approximately constant at 1.0 for the GA between 16-32 weeks. A small left lung (<1st percentile) was defined as a QLI-L < 0.5.

CONCLUSIONS

Fetal left lung growth can be adequately described independent of gestational age using the QLI-L. Further experience is needed to assess the clinical accuracy of the QLI-L in characterizing fetal left lung growth.

Prenatal diagnosis and management of congenital diaphragmatic hernia

Congenital diaphragmatic hernia is characterized by failed closure of the diaphragm, thereby allowing abdominal viscera to herniate into the thoracic cavity and subsequently interfering with normal lung development. At birth, pulmonary hypoplasia leads to respiratory insufficiency and persistent pulmonary hypertension (PHT), that is lethal in up to 32% of patients. In isolated cases, the outcome may be predicted prenatally by medical imaging and advanced genetic testing. In those fetuses with a predicted poor outcome, fetoscopic endoluminal tracheal occlusion may be offered. This procedure is currently being evaluated in a global randomized clinical trial (www.TOTALtrial.eu). We are currently investigating alternative strategies including transplacental sildenafil administration to reduce the occurrence of persistent PHT.