Traitement anténatal de la hernie de coupole diaphragmatique : le point en 2008

Risk factors for congenital diaphragmatic hernia in the Bogota birth defects surveillance and follow-up program, Colombia

PURPOSE

The mortality rate for congenital diaphragmatic hernia (CDH) remains high and prevention efforts are limited by the lack of known risk factors. The aim of this study was to determine prevalence, risk factors, and neonatal results associated with CDH on a surveillance system hospital-based in Bogotá, Colombia.

METHODS

The data used in this study were obtained from The Bogota Birth Defects Surveillance and Follow-up Program (BBDSFP), between January 2001 and December 2013. With 386,419 births, there were 81 cases of CDH. A case-control methodology was conducted with 48 of the total cases of CDH and 192 controls for association analysis.

RESULTS

The prevalence of CDH was 2.1 per 10,000 births. In the case-control analysis, risk factors found were maternal age ≥35 years (OR, 33.53; 95 % CI, 7.02-160.11), infants with CDH were more likely to be born before 37 weeks of gestation (OR, 5.57; 95 % CI, 2.05-15.14), to weigh less than 2500 g at birth (OR, 9.05; 95 % CI, 3.51-23.32), and be small for gestational age (OR, 5.72; 95 % CI, 2.18-14.99) with a high rate of death before hospital discharge in the CDH population (CDH: 38 % vs BBDSFP: <1 %; p < 0.001).

CONCLUSIONS

The prevalence of CDH calculated was similar to the one reported in the literature. CDH is strongly associated with a high rate of death before hospital discharge and the risk factors found were maternal age ≥35 years, preterm birth, be small for gestational age, and have low weight at birth. These neonatal characteristics in developing countries would help to identify early CDH. Prevention efforts have been limited by the lack of known risk factors and established epidemiological profiles, especially in developing countries.

Prematurity and fetal lung response after tracheal occlusion in fetuses with severe congenital diaphragmatic hernia

OBJECTIVE

To evaluate the independent association of fetal pulmonary response and prematurity to postnatal outcomes after fetal tracheal occlusion for congenital diaphragmatic hernia.

METHODS

Fetal pulmonary response, prematurity (<37 weeks at delivery) and extreme prematurity (<32 weeks at delivery) were evaluated and compared between survivors and non-survivors at 6 months of life. Multivariable analysis was conducted with generalized linear mixed models for variables significantly associated with survival in univariate analysis.

RESULTS

Eighty-four infants were included, of whom 40 survived (47.6%) and 44 died (52.4%). Univariate analysis demonstrated that survival was associated with greater lung response (p=0.006), and the absence of extreme preterm delivery (p=0.044). In multivariable analysis, greater pulmonary response after FETO was an independent predictor of survival (aOR 1.87, 95% CI 1.08-3.33, p=0.023), whereas the presence of extreme prematurity was not statistically associated with mortality after controlling for fetal pulmonary response (aOR 0.52, 95% CI 0.12-2.30, p=0.367).

CONCLUSION

Fetal pulmonary response after FETO is the most important factor associated with survival, independently from the gestational age at delivery.

Incidence, predictors and outcomes of congenital diaphragmatic hernia: a population-based study of 32 million births in the United States

OBJECTIVES

To evaluate the incidence, risk factors and neonatal outcomes associated with a congenital diaphragmatic hernia (CDH).

STUDY DESIGN

We conducted a population-based cohort study using the CDC's Linked Birth-Infant Death and Fetal Death data files on all births and foetal deaths in USA between 1995 and 2002. We estimated the yearly incidence of CDH and measured its adjusted effect on various outcomes using unconditional logistic regression analysis.

RESULTS

About 32,145,448 births during the 8-year study period met the study's inclusion criteria. The incidence of CDH was 1.93/10,000 births. Risk factors for the development of CDH included foetal male gender [OR 1.12, 95% CI: 1.06, 1.17], maternal age beyond 40 [OR 1.51, 95% CI: 1.26, 1.80], Caucasian ethnicity [OR 1.15, 95% CI: 1.10, 1.21], smoking [OR 1.34, 95% CI: 1.22, 1.46] and alcohol use during pregnancy [OR 1.37, 95% CI: 1.05, 1.79]. As compared to foetuses with no CDH, foetuses with CDH were at an increased risk of preterm birth [OR 2.90, 95% CI: 2.72, 3.11], intrauterine growth restriction [OR 3.84, 95% CI: 3.51, 4.18], stillbirth [OR 9.65, 95% CI: 8.20, 11.37] and overall infant death [OR: 94.80, 95% CI: 88.78, 101.23]. The 1-year mortality was 45.89%.

CONCLUSION

Congenital diaphragmatic hernia is strongly associated with an increased risk of adverse pregnancy, foetal and neonatal outcomes. These findings may be helpful in counselling pregnancies affected by CDH, and may aid in the understanding of the burden of this condition at the public health level.

Early fetoscopic tracheal occlusion for extremely severe pulmonary hypoplasia in isolated congenital diaphragmatic hernia: preliminary results

OBJECTIVE

To evaluate the effect of early fetoscopic tracheal occlusion (FETO) (22-24 weeks' gestation) on pulmonary response and neonatal survival in cases of extremely severe isolated congenital diaphragmatic hernia (CDH).

METHODS

This was a multicenter study involving fetuses with extremely severe CDH (lung-to-head ratio < 0.70, liver herniation into the thoracic cavity and no other detectable anomalies). Between August 2010 and December 2011, eight fetuses underwent early FETO. Data were compared with nine fetuses that underwent standard FETO and 10 without fetoscopic procedure from January 2006 to July 2010. FETO was performed under maternal epidural anesthesia, supplemented with fetal intramuscular anesthesia. Fetal lung size and vascularity were evaluated by ultrasound before and every 2 weeks after FETO. Postnatal therapy was equivalent for both treated fetuses and controls. Primary outcome was infant survival to 180 days and secondary outcome was fetal pulmonary response.

RESULTS

Maternal and fetal demographic characteristics and obstetric complications were similar in the three groups (P > 0.05). Infant survival rate was significantly higher in the early FETO group (62.5%) compared with the standard group (11.1%) and with controls (0%) (P < 0.01). Early FETO resulted in a significant improvement in fetal lung size and pulmonary vascularity when compared with standard FETO (P < 0.01).

CONCLUSIONS

Early FETO may improve infant survival by further increases of lung size and pulmonary vascularity in cases with extremely severe pulmonary hypoplasia in isolated CDH. This study supports formal testing of the hypothesis with a randomized controlled trial.

Quantitative lung index, contralateral lung area, or lung-to-head ratio to predict the neonatal outcome in isolated congenital diaphragmatic hernia?

OBJECTIVES

To estimate the accuracy of the quantitative lung index and contralateral lung area for prediction of the neonatal outcome in isolated congenital diaphragmatic hernia in comparison to other available prediction models.

METHODS

Between January 2004 and December 2010, 108 fetuses with isolated (82 left-sided and 26 right-sided) congenital diaphragmatic hernia were prospectively evaluated. The quantitative lung index and observed-to-expected contralateral lung area were measured and compared to the neonatal survival rate and severe postnatal pulmonary arterial hypertension, along with the lung-to-head ratio, observed-to-expected lung-to-head ratio, and observed-to-expected total lung volume.

RESULTS

Overall neonatal mortality was 64.8% (70 of 108). Severe pulmonary arterial hypertension was diagnosed in 68 (63.0%) of the cases, which was associated with neonatal death (P < .001). Both the quantitative lung index and observed-to-expected contralateral lung area were significantly associated with neonatal survival and pulmonary arterial hypertension (P < .001), with accuracy to predict survival of 70.9% and 70.0%, respectively, and accuracy to predict hypertension of 78.7% and 72.0%; however, they were both less accurate than the observed-to-expected total lung volume (83.3% and 86.1%; P < .01). The lung-to-head ratio (73.1% and 78.7%) and observed-to-expected lung-to-head ratio (75.9% and 72.2%; P > .05) had similar accuracy as the quantitative lung index and observed-to-expected contralateral lung area.

CONCLUSIONS

The observed-to-expected total lung volume is the most accurate predictor of the neonatal outcome in cases of isolated congenital diaphragmatic hernia. Both the quantitative lung index and observed-to-expected contralateral lung area, albeit reasonably accurate, do not produce the same level of accuracy and render similar results as the lung-to-head ratio and observed-to-expected lung-to-head ratio.

Fetal pulmonary response after fetoscopic tracheal occlusion for severe isolated congenital diaphragmatic hernia

OBJECTIVE

To estimate the response in lung growth and vascularity after fetal endoscopic tracheal occlusion for severe congenital diaphragmatic hernia in the prediction of neonatal survival.

METHODS

Between January 2006 and December 2010, fetal lung parameters (observed-to-expected lung-to-head ratio; observed-to-expected lung volume; and contralateral lung vascularization index) were evaluated before fetal tracheal occlusion and were evaluated longitudinally every 2 weeks in 72 fetuses with severe isolated congenital diaphragmatic hernia. Thirty-five fetuses underwent fetal endoscopic tracheal occlusion and 37 cases did not.

RESULTS

Survival rate was significantly higher in the fetal endoscopic tracheal occlusion group (54.3%) than in the no fetal endoscopic tracheal occlusion group (5.4%, P<.01). Fetal endoscopic tracheal occlusion resulted in a significant improvement in fetal lung size and pulmonary vascularity when compared with fetuses that did not go to the fetal intervention (increase of the observed-to-expected lung-to-head ratio, observed-to-expected total lung volume, and contralateral pulmonary vascularization index 56.2% compared with 0.3%, 37.9% compared with 0.1%, and 98.6% compared with 0.0%, respectively; P<.01). Receiver operating characteristic curves indicated that the observed-to-expected total fetal lung volume was the single best predictor of neonatal survival before fetal endoscopic tracheal occlusion (cutoff 0.23, area under the curve [AUC] 0.88, relative risk 5.3, 95% confidence interval [CI] 1.4-19.7). However, the contralateral lung vascularization index at 4 weeks after fetal endoscopic tracheal occlusion was more accurate in the prediction of neonatal outcome (cutoff 24.0%, AUC 0.98, relative risk 9.9, 95% CI 1.5-66.9) with the combination of observed-to-expected lung volumes and contralateral lung vascularization index at 4 weeks being the best predictor of outcome (AUC 0.98, relative risk 16.6, 95% CI 2.5-112.3).

CONCLUSION

Fetal endoscopic tracheal occlusion improves survival rate by increasing the lung size and pulmonary vascularity in fetuses with severe congenital diaphragmatic hernia. The pulmonary response after fetal endoscopic tracheal occlusion can be used to predict neonatal survival.

Prediction and probability of neonatal outcome in isolated congenital diaphragmatic hernia using multiple ultrasound parameters

OBJECTIVES

To evaluate the accuracy and probabilities of different fetal ultrasound parameters to predict neonatal outcome in isolated congenital diaphragmatic hernia (CDH).

METHODS

Between January 2004 and December 2010, we evaluated prospectively 108 fetuses with isolated CDH (82 left-sided and 26 right-sided). The following parameters were evaluated: gestational age at diagnosis, side of the diaphragmatic defect, presence of polyhydramnios, presence of liver herniated into the fetal thorax (liver-up), lung-to-head ratio (LHR) and observed/expected LHR (o/e-LHR), observed/expected contralateral and total fetal lung volume (o/e-ContFLV and o/e-TotFLV) ratios, ultrasonographic fetal lung volume/fetal weight ratio (US-FLW), observed/expected contralateral and main pulmonary artery diameter (o/e-ContPA and o/e-MPA) ratios and the contralateral vascularization index (Cont-VI). The outcomes were neonatal death and severe postnatal pulmonary arterial hypertension (PAH).

RESULTS

Neonatal mortality was 64.8% (70/108). Severe PAH was diagnosed in 68 (63.0%) cases, of which 63 died neonatally (92.6%) (P < 0.001). Gestational age at diagnosis, side of the defect and polyhydramnios were not associated with poor outcome (P > 0.05). LHR, o/e-LHR, liver-up, o/e-ContFLV, o/e-TotFLV, US-FLW, o/e-ContPA, o/e-MPA and Cont-VI were associated with both neonatal death and severe postnatal PAH (P < 0.001). Receiver-operating characteristics curves indicated that measuring total lung volumes (o/e-TotFLV and US-FLW) was more accurate than was considering only the contralateral lung sizes (LHR, o/e-LHR and o/e-ContFLV; P < 0.05), and Cont-VI was the most accurate ultrasound parameter to predict neonatal death and severe PAH (P < 0.001).

CONCLUSIONS

Evaluating total lung volumes is more accurate than is measuring only the contralateral lung size. Evaluating pulmonary vascularization (Cont-VI) is the most accurate predictor of neonatal outcome. Estimating the probability of survival and severe PAH allows classification of cases according to prognosis.

A randomized controlled trial of fetal endoscopic tracheal occlusion versus postnatal management of severe isolated congenital diaphragmatic hernia

OBJECTIVE

Severe pulmonary hypoplasia and pulmonary arterial hypertension are associated with reduced survival in congenital diaphragmatic hernia (CDH). We aimed to determine whether fetal endoscopic tracheal occlusion (FETO) improves survival in cases of severe isolated CDH.

METHODS

Between May 2008 and July 2010, patients whose fetuses had severe isolated CDH (lung-to-head ratio < 1.0, liver herniation into the thoracic cavity and no other detectable anomalies) were assigned randomly to FETO or to no fetal intervention (controls). FETO was performed under maternal epidural anesthesia supplemented with fetal intramuscular anesthesia. Tracheal balloon placement was achieved with ultrasound guidance and fetoscopy between 26 and 30 weeks of gestation. All cases that underwent FETO were delivered by the EXIT procedure. Postnatal therapy was the same for both treated fetuses and controls. The primary outcome was survival to 6 months of age. Other maternal and neonatal outcomes were also evaluated.

RESULTS

Twenty patients were enrolled randomly to FETO and 21 patients to standard postnatal management. The mean gestational age at randomization was similar in both groups (P = 0.83). Delivery occurred at 35.6 ± 2.4 weeks in the FETO group and at 37.4 ± 1.9 weeks in the controls (P < 0.01). In the intention-to-treat analysis, 10/20 (50.0%) infants in the FETO group survived, while 1/21 (4.8%) controls survived (relative risk (RR), 10.5 (95% CI, 1.5-74.7), P < 0.01). In the received-treatment analysis, 10/19 (52.6%) infants in the FETO group and 1/19 (5.3%) controls survived (RR, 10.0 (95% CI, 1.4-70.6) P < 0.01).

CONCLUSION

FETO improves neonatal survival in cases with isolated severe CDH.

[Congenital diaphragmatic hernia - mechanisms of pulmonary hypoplasia]

Congenital diaphragmatic hernia (CDH) is a common cause of severe neonatal respiratory distress. Mortality and morbidity are determined by the amount of pulmonary hypoplasia (PH) that occurs and by the development of therapy-resistant pulmonary hypertension. The pathogenesis and aetiology of CDH and its associated anomalies are still largely unknown despite all research efforts. The pathogenesis of CDH is based on an assumption linking herniation of abdominal viscera into the thorax with compression of the developing lung. PH, however, can also result from reduced distension of the developing lung secondary to impaired fetal breathing movements. Our understanding of CDH has also been aided by basic research with the use of dietary, teratogen-induced, and knockout models of CDH. These studies indicate that lung hypoplasia may involve disturbances of mitogenic signalling pathways fundamental to embryonic lung development. Recent data reveal the role of disruption of a retinoid-signalling pathway in the pathogenesis of CDH. Although multifactorial inheritance may best explain most cases of CDH in humans, much has been learned about the genetic factors that play a role in the development of CDH by studies of patients with CDH caused by specific genetic syndromes and chromosome anomalies. More research is warranted to improve our understanding of normal and abnormal lung development in relation to CDH. Such investigations will help in the design of new treatment strategies to improve the natural course or even to prevent this anomaly.