The following information may help to address your question:
How does the lung-head ratio (LHR) affect the long-term outlook for individuals with congenital diaphragmatic hernia (CDH)?
The long-term outlook (prognosis) for those with congenital diaphragmatic hernia (CDH) depends on a number of factors, so the lung-head ratio (LHR) cannot be used alone to predict the outcome.
Centers have reported mixed results in the use of LHR for predicting fetal outcome, and its use is known to have limitations. Generally, a high ratio (greater than 1.4) indicates good lung size and is more likely to contribute to a more favorable outcome. A low ratio (variously cited as less than 1.0 or 0.6, depending on the source) indicates small lung size and therefore predicts a poorer outcome.
Fetal MRI is increasingly being used to better define the internal anatomy in fetuses with CDH. Calculation of lung volumes using fast spin-echo MRI reportedly appears to provide useful information about the degree of pulmonary hypoplasia (underdevelopment of the lungs) and seems likely to replace the use of LHR obtained from fetal ultrasound.
Last updated: 10/23/2013
What is the long-term outlook for fetuses or infants with congenital diaphragmatic hernia (CDH)?
The long-term outlook (prognosis) for those with congenital diaphragmatic hernia (CDH) depends on a number of factors, some of which may be assessed during the pregnancy (prenatally); therefore, the outcome is difficult to predict. The prognosis is usually worse when the affected fetus or infant has an abnormal karyotype
or a single gene disorder
; severe associated abnormalities or a heart defect; a right-sided defect or bilateral CDH; liver herniation; and/or a lower fetal lung volume.
A large diaphragmatic defect is more likely to result in pulmonary hypoplasia (underdevelopment of the lungs) and death than a small defect.
It has been reported that anywhere between 20% and 60% of affected individuals (depending on the source) do not survive. For example, while data from specialty centers operating primarily on those with isolated left-sided hernia report 80%-90% survival, population-based studies of outcome for all prenatally diagnosed CDH cases report mortality of at least 50%, if pregnancy terminations are included. A 2003 analysis of a number of studies (a meta-analysis) reported that approximately 25% of all prenatally diagnosed cases were electively terminated; 3% miscarried; and 3% were stillborn
. 31% of the babies born alive died, the majority within the first 24 hours of life.
Many survivors (even those with isolated CDH) experience CDH as a chronic condition. However, reports of essentially normal or near-normal long-term outcomes are increasing. It can be difficult to determine whether certain problems are part of the underlying CDH abnormality or are secondary to treatment. Some affected individuals may experience ongoing respiratory issues, gastrointestinal problems, neurological problems or developmental delay, chest asymmetry, hearing loss, and/or re-herniation.
Individuals seeking specific information about the prognosis for their children or other family members should speak with their health care provider.
Last updated: 10/23/2013
Should fetuses with congenital diaphragmatic hernia (CDH) be delivered early?
The best gestational age for delivery of an infant prenatally diagnosed with CDH is not known. Recommendations have included having a planned induction of labor
between 38 and 39 weeks of gestation so that the fetus is monitored from the earliest stage of labor, and pediatric surgery and neonatology services are prepared to care for the infant. Some researchers have suggested that early delivery at 37 to 38 weeks of gestation may improve survival in infants with CDH because the severity of pulmonary hypoplasia and pulmonary hypertension may increase as the pregnancy progresses. Because up to half of affected infants require extracorporeal membrane oxygenation (ECMO)
, delivery at a tertiary center with ECMO capability has been recommended.
Fetuses with CDH should be closely monitored during the pregnancy. This may entail a nonstress test
twice per week or biophysical profile testing
at 33 to 34 weeks, and ultrasound at 28, 30, 32, and 34 to 35 weeks of gestation to assess fetal growth and amniotic fluid volume. The health care provider should also look for signs of secondary complications such as early stool in the amniotic fluid; dilated stomach in the fetal chest; and abnormal build-up of fluid in the fetal body. These signs may mean that the fetus should be delivered early. Other indications for early delivery may include fetal growth restriction
, too little amniotic fluid (oligohydramnios) and/or other non-reassuring signs.
Last updated: 10/23/2013
We hope this information is helpful. We strongly recommend you discuss this information with your doctor. If you still have questions, please
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