A term infant has initial Apgar scores of 8 and 10 at 1 and 5 minutes. On auscultation of the chest, a heart murmur is audible. There is hepatosplenomegaly. Cataracts of the crystalline lens are noted. The infant is at the 30th percentile for height and weight. Echocardiography shows a patent ductus arteriosus. Which of the following events is the most likely risk factor for the findings in this infant?

**Core Concept**
The underlying condition in this infant is likely a congenital metabolic disorder that affects multiple organ systems, presenting with a combination of clinical features such as hepatosplenomegaly, cataracts, and a patent ductus arteriosus.

**Why the Correct Answer is Right**
The infant's clinical presentation, including the presence of cataracts and a patent ductus arteriosus, suggests a diagnosis of galactosemia, a genetic disorder caused by the deficiency of the enzyme galactose-1-phosphate uridyltransferase (GALT). This enzyme is necessary for the metabolism of galactose, a sugar found in milk and other dairy products. The accumulation of galactose-1-phosphate in the body leads to the formation of toxic intermediates that damage the crystalline lens, causing cataracts, and also affect the heart, leading to the persistence of a patent ductus arteriosus.

**Why Each Wrong Option is Incorrect**
**Option A:** Maternal diabetes is a risk factor for various congenital anomalies, but it is not directly related to the specific combination of findings in this infant.
**Option B:** Intrauterine exposure to maternal phenytoin can cause fetal hydantoin syndrome, characterized by growth restriction, facial abnormalities, and developmental delay, but it does not typically cause hepatosplenomegaly or cataracts.
**Option C:** Maternal use of ACE inhibitors during pregnancy is associated with fetal renal dysfunction and oligohydramnios, but it is not a risk factor for the specific combination of findings in this infant.
**Option D:** Exposure to maternal alcohol during pregnancy can cause fetal alcohol spectrum disorder, characterized by growth restriction, facial abnormalities, and developmental delay, but it is not a risk factor for the specific combination of findings in this infant.

**Clinical Pearl / High-Yield Fact**
Galactosemia is a genetic disorder that can be prevented by avoiding milk and other dairy products in the infant's diet. It is essential to diagnose and manage galactosemia promptly to prevent long-term complications and improve the infant's quality of life.

**Correct Answer: D. Maternal alcohol exposure during pregnancy can cause fetal alcohol spectrum disorder, characterized by growth restriction, facial abnormalities, and developmental delay, but it is not a risk factor for the specific combination of findings in this infant.

✓ Correct Answer: A. Congenital rubella infection