Mieke Cannie

Value of prenatal magnetic resonance imaging in the prediction of postnatal outcome in fetuses with diaphragmatic hernia

To investigate the potential value of antenatally determined total fetal lung volume (TFLV) by magnetic resonance imaging (MRI) in the prediction of the postnatal survival in congenital diaphragmatic hernia (CDH).

Clinical outcome and placental characteristics of monochorionic diamniotic twin pairs with early-and late-onset discordant growth

OBJECTIVE The purpose of this study was to examine the clinical and placental characteristics of monochorionic diamniotic twin pregnancies with early-onset discordant growth diagnosed at 20 weeks, late-onset discordant growth diagnosed at 26 weeks or later, and concordant growth. STUDY DESIGN We studied a prospective cohort that underwent an ultrasound scan in the first trimester, at 16, 20, and 26 weeks. We excluded pregnancies complicated by twin-to-twin transfusion syndrome, miscarriage, fetal death less than 16 weeks, or severe congenital anomalies. Placental sharing and angioarchitecture were assessed by injection of each cord vessel with dyed barium sulphate. The 2 territories were delineated on an X-ray angiogram. The diameter of each intertwin anastomosis was measured on a digital photograph. RESULTS We included 178 twin pairs. Early onset discordant growth, late-onset discordant growth, and concordant growth occurred in 15, 13, and 150 pregnancies, respectively. Twin pairs with early-onset discordant growth had lower survival rates and were delivered at an earlier gestational age than pairs with late-onset discordant and concordant growth. The degree of birthweight discordance was similar in early- and late-onset discordant growth. Severe intertwin hemoglobin differences at the time of birth occurred in 0%, 38%, and 3% of pairs with early-onset discordant growth, late-onset discordant growth, and concordant growth, respectively. The placentas of pairs with early-onset discordant growth were more unequally shared and had larger arterioarterial anastomoses and a larger total anastomotic diameter as compared with placentas of pairs with late onset-discordant or concordant growth. CONCLUSION Unequal placental sharing appears to be involved in the etiology of early-onset discordant growth, whereas a late intertwin transfusion imbalance may be involved in some cases with late-onset discordant growth.

Quantification of intrathoracic liver herniation by magnetic resonance imaging and prediction of postnatal survival in fetuses with congenital diaphragmatic hernia

To quantify the degree of intrathoracic liver herniation by magnetic resonance imaging (MRI) and evaluate its effect on postnatal survival in fetuses with isolated congenital diaphragmatic hernia (CDH).

Prenatal prediction of survival in isolated diaphragmatic hernia using observed to expected total fetal lung volume determined by magnetic resonance imaging based on either gestational age or fetal body volume

To compare the predictive value of the prenatal observed to expected (o/e) lung volume as measured by fetal magnetic resonance imaging (MRI), based on an algorithm using either the gestational age or fetal body volume (FBV), for neonatal survival of fetuses with isolated congenital diaphragmatic hernia (CDH).

Prenatal diagnosis, prediction of outcome and in utero therapy of isolated congenital diaphragmatic hernia.

Congenital diaphragmatic hernia (CDH) can be associated with genetic or structural anomalies with poor prognosis. In isolated cases, survival is dependent on the degree of lung hypoplasia and liver position. Cases should be referred in utero to tertiary care centers familiar with this condition both for prediction of outcome as well as timed delivery. The best validated prognostic indicator is the lung area to head circumference ratio. Ultrasound is used to measure the lung area of the index case, which is then expressed as a proportion of what is expected normally (observed/expected LHR). When O/E LHR is < 25% survival chances are < 15%. Prenatal intervention, aiming to stimulate lung growth, can be achieved by temporary fetal endoscopic tracheal occlusion (FETO). A balloon is percutaneously inserted into the trachea at 26–28 weeks, and reversal of occlusion is planned at 34 weeks. Growing experience has demonstrated the feasibility and safety of the technique with a survival rate of about 50%. The lung response to, and outcome after FETO, is dependent on pre‐existing lung size as well gestational age at birth. Early data show that FETO does not increase morbidity in survivors, when compared to historical controls. Several trials are currently under design. Copyright

Fetal body volume at MR imaging to quantify total fetal lung volume: normal ranges.

PURPOSE To prospectively determine normal ranges of total fetal lung volume (TFLV) based on fetal body volume (FBV) and to determine whether prediction of TFLV based on such ranges is independent of fetal biometric indexes. MATERIALS AND METHODS The study was approved by the Ethics Committee on Clinical Studies; informed consent was obtained. Magnetic resonance imaging volumetric measurement of fetal lung, liver, and body was performed in 200 fetuses without abnormalities affecting these structures. FBV was assessed with planimetric measurements by using T2-weighted half-Fourier rapid acquisition with relaxation enhancement at 16-40 weeks of gestation. TFLV was correlated to gestational age (GA), liver volume, and FBV. Observed-expected (O/E) ratio for TFLV was calculated by expressing the observed TFLV as a percentage of the expected mean TFLV for GA, liver volume, or FBV. Three groups of fetuses were defined on the basis of biometric percentiles for fetal weight obtained through ultrasonography: fetuses with weight at or below the 5th percentile, those with weight at or above the 95th percentile, and those with weight between these two percentiles (eutrophic). Median O/E ratios, based on GA and FBV, in fetuses with weight below the 5th percentile and in those with weight above the 95th percentile, were compared with median O/E ratio of eutrophic fetuses (Mann-Whitney U test). RESULTS TFLV correlated best with FBV, according to the following cubic fit: TFLV = [(2.0 x 10(-9)) x FBV(3)] - [(1.19 x 10(-5)) x FBV(2)] + (0.0508 x FBV) - 1.79 (r(2) = 0.85, P < .001). In 174 eutrophic fetuses, normal median O/E ratio based on GA was 99.1% (range, 31.2%-158.0%), which was higher than that in 11 fetuses with weight at or below the 5th percentile (46.2%; range, 15.7%-87.3%) (P < .01) and lower than that in 15 fetuses with weight at or above the 95th percentile (146.8%; range, 87.2%-204.2%) (P < .01). Normal median O/E ratio, based on FBV, was independent of biometric indexes irrespective of the percentile for fetal weight. CONCLUSION FBV correlated best with TFLV, irrespective of biometric variables.

Acceptance, reliability and confidence of diagnosis of fetal and neonatal virtuopsy compared with conventional autopsy: A prospective study

To compare prospectively maternal acceptance of fetal and neonatal virtuopsy with that of conventional autopsy and to determine the confidence with which magnetic resonance (MR) virtuopsy can be used to diagnose normality/abnormality of various fetal anatomical structures.

Prenatal intervention for isolated congenital diaphragmatic hernia.

Purpose of review We aim to review the recent literature regarding early prenatal prediction of outcome in babies diagnosed with isolated congenital diaphragmatic hernia, as well as results of fetal therapy for this condition. Recent findings Current survival rates in population-based studies are around 55–70%. Highly specialized centers report 80% and more, but discount the hidden mortality, mainly in the antenatal period. Fetuses presenting with liver herniation and a lung-to-head ratio of less than 1.0 measured in midgestation have a poor prognosis. Other volumetric techniques are being evaluated for use in midtrimester. Recently, a randomized trial failed to show benefit from prenatal therapy, but lacked power to document the potential advantage of prenatal therapy in severe cases. We proposed percutaneous fetal endoluminal tracheal occlusion with a balloon at 26–28 weeks through a 3.3 mm incision. In severe cases, fetal endoluminal tracheal occlusion increased lung size as well as survival, with an early (7 day) survival, late neonatal (28 day) survival and survival at discharge of 75, 58 and 50%, respectively, comparing favorably with 9% in contemporary controls. Airways can be restored prior to birth improving neonatal survival (83.3% compared with 33.3%). The procedure carries a risk for preterm prelabour rupture of the fetal membranes, although that may decrease with experience. Summary Fetuses with severe congenital diaphragmatic hernia can be identified in the second trimester. Fetal endoluminal tracheal occlusion can be considered as a minimally invasive fetal therapy, improving outcome in such highly selected cases.

Evidence and Patterns in Lung Response after Fetal Tracheal Occlusion: Clinical Controlled Study

PURPOSE To prospectively assess changes in lung volume in fetuses with isolated severe congenital diaphragmatic hernia (CDH) after fetoscopic endoluminal tracheal occlusion (FETO) compared with those in fetuses with CDH of variable severity who were expectantly managed. MATERIALS AND METHODS Informed consent was obtained for this ethics committee-approved study. Forty fetuses with severe CDH (lung-to-head ratio < 1 and intrathoracic liver) who underwent FETO and 18 fetuses with CDH of variable severity who were expectantly managed were longitudinally followed up by using magnetic resonance (MR) imaging volume measurements. Fetuses born prior to 32 weeks were excluded from the study. For those undergoing FETO, lung volume responsiveness was defined as the proportionate increase in observed-to-expected (O/E) ratio of total fetal lung volume (TFLV) at 2-5 weeks after FETO compared with the pre-FETO value. Changes in lung volume were compared by using the Mann-Whitney U test. Regression analysis was used to investigate the effect of pre-FETO O/E ratio of TFLV, gestational age at FETO and at delivery, lung volume responsiveness, occlusion period, side of CDH, and balloon removal prior to delivery on survival. Correlation between post-FETO lung volume responsiveness and gestational age at FETO was performed by using linear regression analysis. RESULTS A total of 260 MR imaging examinations were performed. For expectantly managed fetuses, O/E ratio of TFLV remained unchanged during gestation, whereas it significantly increased after FETO. Regression analysis demonstrated that pre-FETO O/E ratio of TFLV and lung volume responsiveness at 3.3 weeks after FETO provided significant independent prediction of postnatal survival. There was a significant negative association between lung volume responsiveness and gestational age at FETO. CONCLUSION In fetuses with CDH, pre-FETO O/E ratio of TFLV and lung volume at 3.3 weeks after FETO provide independent prediction of postnatal survival. SUPPLEMENTAL MATERIAL http://radiology.rsnajnls.org/cgi/content/full/2522081955/DC1.

Arabin cervical pessary in women at high risk of preterm birth: a magnetic resonance imaging observational follow-up study.

To help elucidate the mechanism of action of the Arabin cervical pessary in pregnancies at high risk for preterm delivery.