Fetal diastematomyelia associated with vertebral malformation: ultrasound, MRI, and pathomorphological findings

Prenatal Diagnosis of Diastematomyelia: a Case Report and Literature Review

Diastematomyelia is a type of closed spinal dysraphism in which there is splitting of the spinal cord. It is a rare entity that accounts for less than 3% of closed spinal dysraphisms and affects females 1.3 to 6 times more frequently than males. Lesions are usually found in the lower thoracic and upper lumbar regions. It is characterised by two hemicords separated by a bony or cartilaginous spur. In most cases, it is an isolated malformation with a favourable prognosis. However, it may be associated with other abnormalities and sonography is the imaging test par excellence for early prenatal diagnosis. We report a case of diastematomyelia diagnosed by prenatal sonography at 24 weeks' gestation. Amniotic fluid alpha-fetoprotein (AF-AFP) was normal, while amniotic fluid acetylcholinesterase (AF-AChE) was positive. After birth, the diagnosis was confirmed with magnetic resonance imaging (MRI). The anomaly was associated with a spinal lipoma, tethered cord and dermal sinus. A review of all the cases described in the literature to date is carried out.

The Lower Limb Movements of the Fetus in Uterus: A Narrative Review

The fetus movements play an important role in fetal well-being. With the continuous advancement of real-time scanning machines, it is feasible to observe the fetus movement in detail. The characteristics of fetal lower limb movements in prenatal examination have not been systematically investigated. This review proposes the patterns of fetal lower limb movements, the maternal influence on fetal lower limb movements, and the application of fetal lower limb movements for the diagnosis of prenatal diseases. A systematic search of literature on the lower limb movements of the fetus in uterus was performed in the databases, namely, Web of Science and Scopus. Thirty-four publications were selected. This review demonstrates that isolated fetal lower limb movements are rare and always accompanied with the movements of other body segments. Detection of the presence of fetal leg movements seems to be of no diagnostic value for fetuses with prenatal diseases. The isolated lower limb movement was statistically significant different between fetuses of low- and high-risk pregnant women. The coordinated movements of the fetal lower limbs and other parts should be considered when analyzing fetal movements in the future study.

Fetal magnetic resonance imaging in the diagnosis of spinal cord neural tube defects: A prospective study

Objective

This study aimed to evaluate the value of fetal magnetic resonance imaging (MRI) in the prenatal diagnosis of spinal neural tube defects.

Methods

From August 2018 to January 2021, 56 fetuses with suspected spinal cord neural tube defects were treated by prenatal ultrasound in the Neurosurgery Department of the First Medical Center of the People's Liberation Army General Hospital. Fetal MRI was performed within 72 h after ultrasound diagnosis. Forty singleton fetuses were selected. Magnetic resonance examination was performed within 1 month after birth, and the diagnostic coincidence rates of prenatal ultrasound and fetal magnetic resonance examination in the prenatal diagnosis of spinal cord neural tube defects were compared and analyzed using postnatal magnetic resonance examination as the standard.

Results

The coincidence rates of prenatal ultrasound and fetal MRI for the prenatal diagnosis of spina bifida were 71.4% (20/28) and 39.2% (11/28), respectively, and the difference was statistically significant. The coincidence rates of prenatal ultrasound and fetal MRI in the diagnosis of intraspinal lipoma were 52.6% (10/19) and 73.7% (14/19), respectively, and the difference was statistically significant.

Conclusion

Fetal MRI has an advantage over prenatal ultrasound in detecting intraspinal lipoma. Prenatal ultrasound has an advantage over fetal MRI in detecting spina bifida.