The incidence of sudden infant death syndrome peaks between the ages of:

• A. 1 to 2 months.
• B. 2 to 4 months.
• C. 4 to 6 months.
• D. 3 to 5 months.

Answer: (B)

The main idea here is that sudden infant death syndrome most often occurs during a very early, specific window of infancy. Data show the highest risk is in the second to fourth month of life, when autonomic control and arousal mechanisms are still maturing and infants may have sleep patterns that make them more vulnerable. Because the risk rises to a peak during this 2–4 month period and then falls off as the infant’s nervous system develops and protective sleep behaviors become established, the answer that matches this peak window best is 2 to 4 months. After about 6 months, the risk drops more markedly, contributing to the lower incidence in later infancy.