Question

A 3.8 kg baby of a diabetic mother developed seizures 16 hours after birth. The most probable cause is?

• A. Hypoglycemia
• B. Hypocalcemia
• C. Birth asphyxia
• D. Intraventricular hemorrhage

Hint:

In an IDM, glucose falls within hours while calcium drops later (after about 72 hours).

Answer 1

The Correct Option is A

Step 1: Recognize the setting. An infant of a diabetic mother (IDM) who is large for gestational age (3.8 kg) has had chronic intrauterine hyperglycemia driving fetal hyperinsulinemia.
Step 2: Apply the timing of metabolic complications. After birth the maternal glucose supply stops abruptly while the baby's high insulin levels persist, causing early neonatal hypoglycemia. This typically appears within the first few hours and up to the first day of life, comfortably including the 16-hour mark.
Step 3: Contrast with hypocalcemia. IDM-related hypocalcemia is also common but characteristically presents later, generally after 24 to 72 hours of life, so it is less likely as the cause of a seizure at 16 hours.
Step 4: Exclude the remaining options. Birth asphyxia causes encephalopathy that usually manifests in the first 12 to 24 hours but requires a history of a difficult/asphyxiated delivery, which is not given. Intraventricular hemorrhage is mainly a problem of preterm infants, not a term LGA IDM.
Conclusion: Given an IDM presenting with seizures at 16 hours, the most probable cause is hypoglycemia. This matches the printed key (option A); note that hypocalcemia would be favored if the seizure occurred after about 72 hours.