Final answer:
The most direct complication for the newborn of a Group B streptococcus positive mother who does not receive antibiotic treatment is neonatal sepsis. GBS is the main cause of neonatal meningitis, which is preventable if the mother is treated with antibiotics during childbirth.
Step-by-step explanation:
The complication of a Group B streptococcus positive mother who does not receive antibiotic treatment most directly has implications for the health of the newborn, particularly the development of neonatal sepsis. Group B streptococcus (GBS), or S. agalactiae, is the leading cause of neonatal meningitis and can cause infection in infants during childbirth if not treated in pregnant women. Preterm labor, postpartum hemorrhage, and gestational diabetes are not directly associated with untreated GBS positive mothers but can be independent complications of pregnancy.
Diagnosis and treatment of neonatal meningitis can reduce mortality and long-term sequelae. Early onset disease occurs when infants are infected during childbirth, while late-onset can occur up to 3 months of age. The administration of intravenous antibiotics, such as penicillin or ampicillin, during labor to women who are GBS positive can significantly reduce the incidence of early-onset neonatal meningitis.