**Core Concept**
Neonatal sepsis is a life-threatening condition characterized by a systemic infection in newborns, often resulting from vertical transmission from the mother or horizontal transmission from healthcare workers. The risk of neonatal sepsis is higher in premature infants due to their immature immune system.

**Why the Correct Answer is Right**
The most common mode of transmission of infection in neonatal sepsis is vertical transmission from the mother, particularly during delivery. This can occur through the birth canal, placental abruption, or amniotic fluid contamination. Premature rupture of membranes, congenital infections, and maternal infections are also significant risk factors. Healthcare-associated infections, such as those caused by nursery personnel, are less common compared to vertical transmission.

**Why Each Wrong Option is Incorrect**
**Option A:** Premature babies are indeed predisposed to sepsis due to their immature immune system and increased susceptibility to infections. This statement is true.

**Option B:** Late initiation of breastfeeding is a risk factor for neonatal sepsis. Breast milk provides essential antibodies and immune factors that protect newborns from infections. Delayed breastfeeding can increase the risk of sepsis. This statement is true.

**Option D:** Premature rupture of membranes (PROM) is a significant risk factor for neonatal sepsis. PROM can lead to chorioamnionitis, which increases the risk of vertical transmission of infections to the fetus. This statement is true.

**Clinical Pearl / High-Yield Fact**
A key aspect of neonatal sepsis is the importance of early recognition and treatment. The American Academy of Pediatrics recommends that all newborns with signs of sepsis, such as fever, apnea, or lethargy, undergo a thorough evaluation, including blood cultures and imaging studies.

✓ Correct Answer: C. Most common transmission of infection is through nursery personel.