IMPORTANT: We currently have a number of bugs related to image cropping and are actively trying to resolve them. In the meantime, we have disabled cropping. Apologies for any inconvenience. Stay informed: radiopaedia.org/chat

Neural tube defect in monochorionic diamniotic twin pregnancy

Case contributed by Alexandra Stanislavsky
Diagnosis certain

Presentation

Second trimester morphology ultrasound

Patient Data

Age: 30 years
Gender: Female

Gestation: 18w1d, MCDA pregnancy.

TWIN 1 (maternal right, cephalic presentation): Biometry normal for gestational age. Normal fetal anatomy. DVP: 4.8 cm

 TWIN 2 (left side breech presentation): Biometry normal for gestational age.
The following abnormalities are demonstrated:

  • Mild ventriculomegaly with lateral ventricles measuring 11 mm on both sides. CSP and corpus callosum not identified, possibly due to the early gestation and ventriculomegaly.
  • The cerebellum is displaced posteriorly consistent with Chiari type 2 malformation. 
  • There is a neural tube defect extending from L4/L5 down through the sacral spine. The conus appears to extend into the defect. 
  • Bilateral talipes

Deepest pool: 3.8 cm

Placenta: Posterior, not low lying. Twin 1 centric cord insertion; twin 2 velamentous cord insertion. The cervix is long and closed.

Case Discussion

MCDA pregnancy with twin 2 demonstrating typical antenatal features of a neural tube defect - including a lemon-shaped head, posteriorly displaced "banana" cerebellum, ventriculomegaly and a lumbar myelomeningocele.

How to use cases

You can use Radiopaedia cases in a variety of ways to help you learn and teach.

Creating your own cases is easy.

Updating… Please wait.

 Unable to process the form. Check for errors and try again.

 Thank you for updating your details.