Screening for Fetal Spina Bifida Aperta by the Ultrasound and Intracranial Translucency Examinations at 11–13+6 Weeks of Gestation

Abstract

The objective of the study is to evaluate the clinical significance of screening for fetal spina bifida aperta by ultrasound examination and intracranial translucency (IT) measurement at 11-13(+6) weeks of gestation. About 1,479 women at 11-13(+6) weeks of gestation in our hospital in 2012 were included as observation group, and 1,608 women at 11-13(+6) weeks of gestation without IT measurement in 2011 was included as controls. Detection rates of fetal spina bifida aperta in two groups were compared. The translucency thickness between the brain stem and choroid plexus and crown-rump length (CRL) in mid-sagittal view of the fetal face was measured, and translucency thickness and CRL in fetuses with spina bifida and healthy ones were compared. Detection rate of fetal spina bifida aperta in observation group was significantly higher than that in control group (six cases in observation group and one case in control group, p=0.046). IT thickness was significantly lower in fetuses with spina bifida aperta (0.01±1.25mm) than that in healthy ones (1.73±0.32mm) (p<0.001). There was positive correlation in healthy fetuses between IT thickness and CRL (r=0.702, p<0.001), but not in fetuses with spina bifida aperta (r=0.001, p=0.081). Ultrasound examination with IT measurement at 11-13(+6) weeks of gestation can be used to screen for fetal spina bifida aperta, and the reduction of IT thickness is an indicator of spina bifida aperta.