Abstract
Purpose: There are many reports on the prenatal severity index, which is a measure of the lung capacity of fetuses with congenital diaphragmatic hernia (CDH). However, whether this index can serve as a true measure for evaluating cardiopulmonary hypoplasia remains controversial. We devised an index for measuring the severity of prenatal CDH by fetal cardiac ultrasonography and for evaluating the prognosis.
Methods: Since 1997, we have performed 57 fetal cardiac ultrasonography procedures on 27 fetuses with left isolated CDH at our institution. These 27 fetuses did not have any other malformations. Ninety-nine fetuses without cardiac or lung disease served as the control group. We examined the outcomes on the basis of the tricuspid valve-to-mitral valve diameter ratio (TV/MV ratio), pulmonary valve-to-aortic valve diameter ratio (PV/AV ratio), and cardiothoracic area ratio (CTAR). Next, we compared the survival group (SG) with the nonsurvival group (NSG) and retrospectively examined the blood flow direction of the ductus arteriosus using clinical data.
Results: CTAR, PV/AV ratio, and TV/MV ratio were significantly different between the control group and the CDH group. CTAR was significantly different between SG and NSG (p = 0.01), whereas PV/AV ratio was not significantly differently between these groups. TV/MV ratio was significantly different between NSG and SG (p < 0.001). For patients of advanced gestational age, TV/MV ratio increased in NSG. CTAR and PV/AV ratio were not significantly different in relation to the blood flow direction of the ductus arteriosus, whereas TV/MV ratio was significantly different between NSG and SG.
Conclusion: Fetal cardiac ultrasonography is valuable for prenatal diagnosis of CDH. In particular, TV/MV ratio reflected severity 32 weeks later and is thus useful as a prenatal severity index.
