**Question:** Most characteristic anomaly in infant of a diabetic mother:

A. Anencephaly
B. Micrognathia
C. Hypospadias
D. Cleft lip and palate

**Core Concept:** The most characteristic anomaly in an infant born to a diabetic mother is due to the increased risk of congenital anomalies in such pregnancies, mainly caused by maternal diabetes.

**Why the Correct Answer is Right:** In infants of diabetic mothers, the most common congenital anomaly is micrognathia, which is a deficiency in the development of the mandible leading to a small jaw. This is a result of the increased glucose levels crossing the placenta and affecting the mandibular growth centers during the critical developmental periods.

**Why Each Wrong Option is Incorrect:**

A. Anencephaly (absence of the brain and skull) is not a characteristic anomaly in infants of diabetic mothers; rather, it is associated with neural tube defects, which are caused by different genetic factors.
B. Cleft lip and palate are related to maternal teratogens like alcohol, retinoic acid, and some antibiotics, not maternal diabetes.
C. Hypospadias (inappropriate opening of the urethra on the ventral aspect of the penis) is more common in infants of diabetic mothers, particularly those with poor glycemic control during pregnancy. However, it is not the most characteristic anomaly.
D. Cleft lip and palate are associated with maternal teratogens, not maternal diabetes.

**Clinical Pearl:** Diabetic mothers need strict glycemic control and regular prenatal monitoring to minimize the risk of congenital anomalies in their offspring. Early diagnosis and appropriate management of gestational diabetes can significantly reduce the occurrence of micrognathia and other congenital anomalies.

**Correct Answer:** D. Cleft lip and palate (micrognathia is the most characteristic anomaly)

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In summary, micrognathia is the most characteristic anomaly in infants of diabetic mothers, whereas microcephaly, which is associated with anencephaly, is not. Congenital anomalies in infants of diabetic mothers are primarily caused by poor glycemic control during pregnancy, leading to developmental abnormalities in multiple organ systems. Close monitoring and strict glycemic control can significantly reduce the risk of such anomalies.