Three-step segmental approach for prenatal ultrasonography in diagnosis of fetal heterotaxy syndrome

Objective To explore the clinical value of fetal ultrasonography in prenatal diagnosis of heterotaxy syndrome.Methods Three-step segmental approach prenatal ultrasound was performed in 40 884 fetuses.The maternal age ranged 20—33(mean 23.6±4.3) years,and the gestational age was 14—38(mean 27.4±6.5) weeks.Eleven fetuses were diagnosed as heterotaxy syndrome,their ultrasonographic manifestations were comparatively analyzed with postpartum autopsy findings.Results Of 11 fetuses,there were 8 fetuses with right isomerism(RI) and 3 fetuses with left isomerism(LI).Ten fetuses of heterotaxy syndrome were confirmed by postpartum autopsy after induced abortion.Important ultrasonographic markers of heterotaxy syndrome included viscero-cardiac heterotaxy,interruption of inferior vena cava with azygous continuation or juxtaposition of inferior vena cava and abdominal aorta,as well as cardiac malformations.Conclusion Prenatal ultrasound in diagnosis of heterotaxy syndrome is feasible.Three-step segmental approach prenatal ultrasound can obtain comprehensively and orderly important ultrasonic signs of heterotaxy syndrome,therefore reducing misdiagnosis.