True about neonatal sepsis:a) Early sepsis is due to organism in maternal genital tractb) Environmental factors cause late sepsisc) Late sepsis is due to organism in maternal genital tractd) Environmental factors cause early sepsis

**Core Concept**
Neonatal sepsis refers to a life-threatening condition caused by a bacterial or fungal infection in a newborn. The timing and source of the infection are crucial in understanding the pathophysiology of neonatal sepsis.

**Why the Correct Answer is Right**
Early neonatal sepsis (within the first 72 hours of life) is primarily caused by organisms present in the maternal genital tract, including Group B Streptococcus, Escherichia coli, and Listeria monocytogenes. These organisms can ascend from the vagina and cervix into the amniotic fluid and then to the fetus during labor. This mode of transmission is a key factor in the development of early-onset neonatal sepsis.

**Why Each Wrong Option is Incorrect**
**Option A:** This statement is correct, as we discussed above. Early sepsis is indeed due to organisms in the maternal genital tract.

**Option B:** Late sepsis is not caused by environmental factors but rather by organisms acquired from the hospital environment, other healthcare workers, or family members. Environmental factors can contribute to the development of late-onset sepsis, but they are not the primary cause.

**Option C:** This statement is incorrect because late sepsis is not due to organisms in the maternal genital tract. Late-onset sepsis typically occurs after 72 hours of age and is often caused by organisms acquired from the hospital environment or other sources.

**Option D:** This statement is incorrect because environmental factors can contribute to the development of late-onset sepsis but are not the primary cause of early sepsis.

**Clinical Pearl / High-Yield Fact**
A key aspect of neonatal sepsis is the timing of the infection. Early-onset sepsis (within 72 hours) is usually caused by organisms from the maternal genital tract, whereas late-onset sepsis (after 72 hours) is often caused by hospital-acquired organisms.

**Correct Answer: A. Early sepsis is due to organism in maternal genital tract.**