Ultrasound Prediction of Fetal Pulmonary Hypoplasia in Pregnancies Complicated by Oligohydramnios and in Cases of Congenital Diaphragmatic Hernia: A Review

Abstract

The objective of this review is to discuss the current knowledge of fetal pulmonary hypoplasia and to summarize the clinical significance of the many ultrasound methods for predicting pulmonary hypoplasia in pregnancies complicated by oligohydramnios due to spontaneous rupture of the fetal membranes and in cases complicated by fetal congenital diaphragmatic hernia. We concluded that the presence or absence of polyhydramnios, fetal breathing movements, mediastinal shift, thoracic position of the stomach, fetal breathing-related nasal and oropharyngeal fluid flow, ductal flow velocity modulation, and gestational age at onset and severity of ventricular disproportion as useful markers for predicting fetal pulmonary hypoplasia is a productive area for continued research. All studies show that there is a clear association between most of these markers and pulmonary hypoplasia. However, these markers have not been studied together in a large number of cases, and comparisons between each of the markers is unknown.

Normal fetal lung volume measured with three-dimensional ultrasound

“…Conventional 2D ultrasound has been used to evaluate fetal breathing movements, thoracic circumference, lung length and the ratio of thoracic circumference to abdominal circumference in order to predict lung volume. However, these parameters were not sufficiently sensitive or specific for clinical management in cases of pulmonary hypoplasia1–8. It has been shown that measuring lung volume with magnetic resonance imaging (MRI) has benefits over conventional 2D ultrasound38–45, particularly with the new high‐speed systems, which have clearer MR images with fewer motion artifacts.…”

“…Conventional two‐dimensional (2D) ultrasound, which is used routinely in obstetrics, has not proved sufficiently reliable to be used in the clinical diagnosis and management of pulmonary hypoplasia1–8. However, recent studies have indicated the value of three‐dimensional (3D) ultrasound.…”

Fetal pulmonary development: the role of respiratory movements

“…Such evidence may be obtained in fetuses exposed to oligohydramnios. As discussed below, some, but not all, reports indicate that such fetuses are more likely to develop lung hypoplasia if FBM are absent or reduced in incidence (Fox and Badalian 1994).…”

Estudo do volume pulmonar fetal na predição dos resultados perinatais de fetos com derrame pleural "isolado

“…do pulmão acometido131 , levando a condições de alta morbidade e mortalidade (50 -70%) no período neonatal 132. Uma vez que a hipoplasia pulmonar pode ser caracterizada pelo tamanho reduzido dos pulmões fetais, muitos estudos foram realizados com o intuito de se aferir o tamanho e o volume pulmonar90,132,[140][141][142][143] na tentativa de estimar a probabilidade do seu desenvolvimento[141][142][143][144] . Para esse fim, utilizou-se a pulmonar apenas nos casos de hérnia diafragmática congênita151,152 , embora isso não seja consenso na literatura.Raríssimos trabalhos descrevem a avaliação do volume pulmonar nos casos de derrame pleural pela ultrassonografia bidimensional.…”