Assessment of neural tube defects in fetuses: accuracy of imaging and correlation of findings with neuro-urologic outcomes

Abstract

Purpose In order to provide accurate information to parents whose fetus has a neural tube defect (NTD) we evaluated the accuracy of the assigned lesion level by prenatal ultrasound (US) and magnetic resonance (MRI) with postnatal imaging, neuro-motor assessment and urodynamic studies (UDS). Material and methods The retrospective review involved all pregnant women whose fetus had a NTD who were counselled at our fetal center between August 1999 and January 2006. Prenatal imaging (US/MRI) defined a lesion level in 38 of 55. Findings were compared with available postnatal imaging (N = 9) neuro-motor level (N = 15) and urodynamic findings (N = 17). Results US and MRI were equally accurate in demonstrating the anatomic level in 23 of 24 (95.8%) fetuses prenatally. Twenty of 38 women delivered a live-born infant. Lesion levels from prenatal and postnatal imaging correlated within one vertebral level in 9 of 9. The postnatal neuro-motor level was similar or caudad to the anatomic prenatal imaging level in 12 of 15 (80%) and > 2 vertebral levels (either cephalad or caudad) in only 4 of these 15 (26.6%). Prenatal imaging levels did not correlate with postnatal urodynamic function. Conclusions US and MRI are equally accurate in demonstrating the anatomic NTD level in utero. Postnatal neuro-motor level is often more caudad than the identified anatomic level. The relationship between estimated anatomic level and urodynamic function is not predictable by prenatal imaging. Caution should be exercised in predicting functional outcomes during prenatal counseling based on the prenatal anatomic level of the NTD.