OBG - Anencephaly

Question 1

Factors that increase risk for anencephaly?

Answer 1

Family history of neural tube defects
Exposure to certain agents (hyperglycemia in DM), hyperthermia, drugs/meds (depakote, carbamazepine, aminopterin, isotretinoin)
Genetic syndromes
High-risk racial/ethnic groups/regions

Question 2

Women with increased risk of neural-tube defects are offered ___ testing as part of a diagnostic work-up.

Answer 2

AFP

Question 3

Useful imaging modalities for evaluating anencephaly?

Answer 3

U/A

Question 4

Anencephaly can theoretically be diagnosed as early as ___ weeks; however, it can be missed in the first trimester. What is the accuracy in the second semester with U/S?

Answer 4

8; 100%

Question 5

What are the findings of anencephalic pregnancy?

Answer 5

Absence of the cranial vault and brain above the base of the skull and orbits

Failure to obtain an adequate view of the biparietal diameter in T2 should raise suspicion

Hydramnios from impaired fetal swallowing commonly accompanies anencephaly (late finding)

Question 6

Findings indicative of another neural tube defect?

Answer 6

Lemon sign (frontal notching, head loks like a lemon)

Banana sign (elongated cerebellum)

Obliteration of the cisterna magna

Ventriculomegaly with the lateral ventricle width >10 mm

Small biparietal diameter