Study of fetal tracheal fluid velocities using Doppler ultrasound.

OBJECTIVE: To characterize tracheal fluid flow during fetal breathing movements by Doppler ultrasound. STUDY DESIGN: To use pulsed Doppler to measure flow velocity during inspiration and expiration in a cross-sectional study of 15 normal fetuses and determine the correlation, if any, between flow velocity and gestational age. RESULTS: Cyclic respiratory profiles - both regular and irregular - were observed. Intratracheal flow velocity was very elevated during inspiration, ranging from 10 to 80 cm/s and from 5 to 20 cm/s during expiration. CONCLUSION: This technique enables the noninvasive semiquantitative evaluation of fetal breathing movements. This Doppler application opens the field for future studies to characterize the extent of pulmonary hypoplasia.

Matthew-Wood syndrome: report of two new cases supporting autosomal recessive inheritance and exclusion of FGF10 and FGFR2.

We describe two fetal cases of microphthalmia/anophthalmia, pulmonary agenesis, and diaphragmatic defect. This rare association is known as Matthew-Wood syndrome (MWS; MIM 601186) or by the acronym "PMD" (Pulmonary agenesis, Microphthalmia, Diaphragmatic defect). Fewer than ten pre- and perinatal diagnoses of Matthew-Wood syndrome have been described to date. The cause is unknown, and the mode of transmission remains unclear. Most cases have been reported as isolated and sporadic, although recurrence among sibs has been observed once. Our two cases both occurred in consanguineous families, further supporting autosomal recessive transmission. In addition, in one family at least one of the elder sibs presented an evocatively similar phenotype. The spatiotemporal expression pattern of the FGF10 and FGFR2 genes in human embryos and the reported phenotypes of knockout mice for these genes spurred us to examine their coding sequences in our two cases of MWS. While in our patients, no causative sequence variations were identified in FGF10 or FGFR2, this cognate ligand-receptor pair and its downstream effectors remain functional candidates for MWS and similar associations of congenital ocular, diaphragmatic and pulmonary malformations.