This article is from the Group B Strep FAQ, by email@example.com (Cheryl Sandberg) with numerous contributions by others.
Giving antibiotics (such as penicillin) through the vein during labor and
delivery to women who have a positive GBS test or who have certain risk
factors effectively prevents most GBS infections in women and their
newborns. For best protection, the mother would receive intravenous
antibiotics at least 4- 6 hours before delivery. However, the earlier the
administration of antibiotics the better once a risk factor has been
identified. For example , a woman who has had a previous GBS baby should
have IV antibiotics started at the time of hospital admission, whether
labor takes 14 hours or 6 hours.
If a woman's labor begins or her membranes rupture before 37 weeks of
pregnancy (before a culture is collected) she should be offered IV
Since the antibiotics can cause side-effects, which are usually mild but
can be severe, their use should be limited to those women who have one or
more of the listed risk factors- the decisions to take antibiotics during
labor should balance risks and benefits. If you are allergic to penicillin,
consult your doctor to learn about other effective antibiotics.
Caesarean sections are not likely to prevent GBS disease.
Unfortunately, no prevention plan is 100% effective. Some women with GBS
escape detection because they do not have risk factors. *All* women should
be tested for GBS with **EACH** pregnancy to ensure that the very best
available protection is provided for their babies.