Obstetric Ultrasound of Fetal Spine and Limbs

Examination of the vertebral column and the spine

- You should examine fetal vertebrae by visualizing them in the saggital and parasaggital planes tilting the transducer so you can identify three parallel lines (rossettes) this excludes spina bifida.

- Examination should be from the cervical down to the sacral region (to avoid missing sacral agenesis). Also make sure no cysts or masses arising from the posterior aspect of the VC to exclude meningeocele and meningeomyelocele.

- One of the important point of examination is noticing movement of the fetus. Movement of the lower limbs is an important sign of spinal cord integrity.

Examination of Fetal Limbs:

a. Assure presence of 4 limbs and presence of 3 bones in each limb.

b. Assure measures of long bones femur length and humeral Length correlate with other fetal measures and gestational age, short measure of long bones is another marker that may signify chromosomal anomalies, osteochondroplasia ...etc.)

c. Assure feet are oriented properly (to exclude talipes) this is very easy in early scans around 18 weeks onward and difficult as the fetus grows and gets "stuck” in the uterus.

d. Assure limb movement is seen especially lower limbs.