Congenital malformations diagnosed in the first trimester – Obstetrics MCQ

Foetus with anencephaly

Which of the following congenital malformations can be diagnosed in the first trimester ?

A. Microcephaly
B. Anencephaly
C. Meningocele
D. Encephalocele

Correct answer : B. Anencephaly

Congenital malformations diagnosed in the first trimester

• Routine ultrasound scan for the diagnosis of congenital anomalies is done in the second trimester
• But in high risk cases, an early anomaly scan is done to identify major anomalies
• The congenital anomalies that can be identified in the first trimester are:
  • Acrania – Condition in which the flat bones of the cranial vault are partially or completely absent. It is an early stage of anencephaly.
  • Exencephaly – An early stage of anencephaly in which the brain is located outside the skull
  • Anencephaly – Absence of a major part of the brain, skull and scalp. It is an anomaly that occurs when the rostral end of the neural tube fails to close.