Methodology of prenatal ultrasound examinations in congenital diaphragmatic hernia

Abstract

Background. Congenital diaphragmatic hernia is a complex malformation with high anatomical and clinical variability. Prenatal ultrasound examinations allow one to assess the severity of pathological process in a particular case in order to determine the management of pregnancy, labor and neonatal period. However, the rarity of this pathology and some features of ultrasound imaging can lead to low informative value of the examination. Purpose – to present a detailed methodology of prenatal ultrasound examinations in fetal congenital diaphragmatic hernia, taking into account anatomical variants of pathology and features of US imaging at different terms of pregnancy, and to characterize the preconditions for diagnostic errors. Materials and methods. The data on prenatal ultrasound examinations of 265 high-risk pregnant women with fetal diaphragmatic hernia conducted during the period of 2007–2020 in the Department of Fetal Medicine of State Institution «Institute of Pediatrics, Obstetrics and Gynecology named after Academician O.M. Lukyanova of National Academy of Medical Sciences of Ukraine», were systemized. US examinations were performed on systems HDI 4000, ACCUVIX V20EX-EXP, ACCUVIX V10LV-EX. Isolated anomaly was detected in 192 (72.5 %) cases, associated congenital malformations in 65 (24.5 %), chromosomal pathology in 8 (3.0 %). Left-sided hernia was diagnosed in 85.7 % of cases (n = 227), right-sided – in 12.1% (n = 32), central in 1.1 % (n = 3), bilateral in 1.1 % (n = 3). Location of abdominal, retroperitoneal and thoracic organs was determined, as well as specifics of their US imaging in different terms of pregnancy. Results. Methodology of prenatal ultrasound examination of fetuses with congenital diaphragmatic hernia was developed taking into account the specifics of pathological anatomy and ultrasound imaging. Typical and rare variants of thoracic and abdominal organs’ localization in the standard cross section plane at the level of the four chambers of the heart were characterized, preconditions and variants of diagnostic errors were determined. The methods of correct measurement of the thorax, lungs, liver, and also methods of prognostic indices’ calculation for determining the degree of pulmonary hypoplasia and the degree of liver herniation were presented. Conclusions. Prenatal ultrasound semiotics of congenital diaphragmatic hernia is characterized by considerable variability, and contains significant risks of diagnostic errors. The presented methodology of unified ultrasound examinations allows for systematic assessment, which results in correct prenatal diagnosis, determination of the pathology severity, and prognosis – for the correct choice of pregnancy and labor management.