Final answer:
The culture for Group B streptococcus during pregnancy is obtained at 36 weeks. This allows the use of intravenous antibiotics during labor to prevent early onset GBS disease in the newborn, including conditions such as neonatal meningitis.
Step-by-step explanation:
The culture for Group B streptococcus (GBS) screening during pregnancy is typically obtained between 35 and 37 weeks gestation. This timing is chosen because it is close to delivery, providing the most accurate indication of whether the mother will be colonized with GBS at the time of birth. Therefore, the correct answer to the question is d) 36 weeks. It's important to undergo this test as an accurate GBS status allows for the administration of appropriate intravenous antibiotics during labor to prevent early onset GBS disease in the newborn, which can lead to conditions like neonatal meningitis. If a mother is found to be GBS positive, the Centers for Disease Control and Prevention (CDC) guidelines recommend the administration of antibiotics at least 4 hours before delivery to effectively reduce the risk of transmitting the bacteria to the newborn. Late-onset GBS disease can also occur, but this is less common than early onset and can be from sources other than the mother.