Feasibility of quantitative measurement of fetal trachea and bilateral bronchial angles by ultrasound to diagnose heterotaxy syndrome in middle and late pregnancy / 中华围产医学杂志

ABSTRACT

Objective@#To analyze the feasibility of prenatal ultrasound quantitative measurement of the angles between trachea and bilateral bronchi as a new diagnostic tool for fetuses with heterotaxy syndrome.@*Methods@#The angles between trachea and bilateral bronchi were measured at 18-34+6 gestational weeks for 200 fetuses with normal ultrasound findings (normal group) and 41 fetuses with heterotaxy syndrome [35 right atrial isomerisms (right group) and six left atrial isomerisms (left group)] diagnosed by ultrasound and confirmed after abortion or induction (case group) in Chongqing Health Center for Women and Children from October 2015 to December 2018. Scatter plots of left/right bronchus angle (α/β) ratios were drawn. Differences in bilateral bronchus angles between the three groups were statistically analyzed using one-way analysis of variance and paired t-test.@*Results@#In the normal group, scatter plots showed the α/β ratios were relatively constant at 0.8-1.0 with larger β than α (t=-33.14, P<0.05), indicating that the right bronchus always went more steeply than the left one. In the case group, the α/β ratios were around 1.0. In the right group, the α value increased and was close to the β value [(153.90±5.43)° vs (156.02±5.59)°, t=-2.56, P>0.05] and presented as bilateral right bronchial angle; in the left group, the β value decreased and was close to the α value [(147.38±3.16)° vs (148.82±5.56)°, t=-1.18, P>0.05] and presented as bilateral left bronchial angle. There were significant differences in the α and β values among the normal group, the right and left groups (all P<0.05), and the bronchial angles of the right group were both greater than those of the left group (all P<0.05).@*Conclusions@#Prenatal ultrasound measurement of the angles between trachea and bilateral bronchi can be used as an indirect indicator for the diagnosis of heterotaxy syndrome.