Protecting the newborn against GBS

Since the introduction of antibiotic prophylaxis for carriers of the bacteria and those at risk in the 1990s, rate of this infection among newborns has fallen quite substantially.

The most effective way to protect the newborn against this infection is to give antibiotics to a known carrier of the bacteria during labor. This is a strategy that prevents transmission of the bacteria to the baby in 95% of cases. Penicillin is very effective but for those women who are allergic to this antibiotic, equally effective alternatives are available.

GBS: Increased risk

There are groups of women whose babies are particularly at risk of developing early-onset disease. For these women, antibiotic prophylaxis is imperative. The groups are:

Ø Where there has been prolonged rupture of membranes. This is generally defines as an interval of more than 18 hours between membrane rupture and delivery

Ø Preterm labor; that is before 37 weeks of gestation

Ø Raised temperature of 38˚C or above during labor.

Ø Previous infant with early onset GBS infection.

Antibiotics Regime for GBS

Antibiotics are given intravenously (i/v)as soon as the woman is in established labor and 4 hourly thereafter until delivery. Number of administrations of the drug will therefore depend on the duration of labor.

Penicillin is usually used with Clindamycin being the alternative where a woman is allergic to Penicillin. Clindamycin is administered 8 hourly. There are a number of other effective alternatives.

Role of Cesarean Section in GBS ‘infection’

The use of antibiotics specifically targeting GBS appears to be of little or no value when delivery is by an elective cesarean section.

Group A Streptococcal Disease

This is mentioned briefly here for clarity and to make the distinction between this and its cousin discussed above.

Group A streptococcus, also known as Streptococcus pyogenes is the bacteria that causes what is generally known as Streptococcal disease. It is usually a disease of childhood and presents as acute sore-throat (pharyngitis). This may then be accompanied by a generalized rash mainly in the upper part of the body. It is then called ‘Scarlet Fever’. This infection has no relationship to Group B streptococcal infection.

Exposure of a pregnant woman to a patient with Scarlet Fever poses no direct risk to the unborn baby.

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