GBS

What is Group B Strep?

Group B streptococcus (GBS) is a normal bacterium that is carried in the vaginal or rectal areas of 10 to 30 percent of all adults, but only 2 percent of laboring women will test positive for GBS. It is ordinarily harmless and goes unnoticed, unless it is passed from mother to baby in childbirth where it can cause serious infection and even death. Babies who develop GBS infection may also develop neurological disorders, vision or hearing loss, cerebral palsy, developmental delays and other permanent disabilities. It is the most common cause of sepsis in newborns.

How common is it?

Approximately 0.75 in every 1000 babies born at 37 weeks or more* contracts GBS, but most will not show symptoms of infection, and if symptoms appear, most recover well with antibiotics. If you are GBS negative and have no risk factors, the risk is 0.3 in 1000. The risk of death without antibiotics is 0.01 in 1000, and the rate of anaphylactic shock due to an antibiotic reaction (even if not allergic before) is 0.01 in 1000.

What are the risk factors?

In addition to being GBS positive, other risk factors for transmitting GBS are: low birthweight, previous GBS-infected baby, urinary tract infection with GBS prenatally, yeast infection, multiple sex partners within the last year, external genital redness and scaling, use of tampons, purulent vaginal discharge, vaginal pH over 5, onset of labor before 37 weeks, rupture of membranes before 37 weeks, rupture of membranes more than 18 hours before birth, internal fetal monitoring for over 12 hours, multiple birth, obesity, black race, age less than 20 years old, fever of 100.4 degrees or more during labor, and immune system compromise. Those mothers with 1 or more of the clinical risk factors above and a positive GBS culture are at most risk of infecting their babies.

Is testing available?

A vaginal/rectal swab at 35-37 weeks which cultures for GBS is routinely done by nurse-midwives and hospital providers. Because GBS can be intermittent, chronic, or transient, the test can miss up to 10% of GBS positive women. I provide a urine test at each prenatal to determine your pH and whether you are presenting with symptoms of a UTI, and can provide the test if you desire to know if you are a carrier.

What treatments are there?

Research indicates that IV antibiotics in labor at the hospital can reduce the risk of GBS transmission by 66 percent. There are a variety of alternative therapies available in a non-interventive home environment: prenatal immunotherapy or improvement of the vaginal flora by changing the pH with hydrogen peroxide, vinegar, or consumption of cultured foods such as acidophilus or garlic; intrapartum immunotherapy or antibacterial agents such as a vaginal wash (not a douche) of herbs or a special soap called Hibiclens (the only agent proven by research to be similar in efficacy as IV antibiotics at reducing GBS). At Northeast Kansas Homebirth Service, there is no forced testing nor treatment.

*Homebirth prior to 37 weeks is not recommended.

References:

Bell, p59-60

Birthkit 38, p3

Brandi W., Hismidwives email list, 01/21/06

Davis, p30

Enkin p98-99

“Genito-Urinary Tract Health” by Gail Hart

HelpingHands email, Lynette C., 10/12/04

Hibiclens insert

ICAN email, Jenny G. [via Willa P.], 11/04/99

Mothering 121, p58