GBS+: Specific, Research-based questions

Mmm. I'm sure it's too late to be helpful to you, but for the record . . .

No. I never did get answers to my questions. I think maybe the research hasn't been done. Which annoys me, because I think they are good questions. However, what I did was to look at the research that does exist and think prayerfully about what level of risk I was willing to accept.

I decided not to take the IV ABX. I felt that the postpartum protocol my CNMs were going to ask me to do (checking baby's vital signs every 4 hours) was better protection than ill-timed or possibly ineffective ABX and would give us adequate warning to get excellent medical treatment if our baby did get sick. And while the infection rate w/no IV ABX was higher than I liked, the DEATH rate was very, very low and a level of risk I felt I could accept. Life is risky. Nothing is going to keep every baby safe, no matter how much we wish it could.

I had discussed all this w/my MW, and she wrote "ABX declined" on the top of my chart w/out even asking me while I was in labor.

My baby was perfectly healthy and still is - except, unfairly, we still got thrush and it keeps coming back, despite my best efforts to get rid of it :-(

I did my research on GBS using two textbooks from the biomedical library at the U of Minnesota.....maybe your medstudent friend could score some OB texts. I am referencing the notes I scrawled in 2002 as I contemplated a home birth, which would mean I'd have to be cool with an abx-free birth. During my first pg I requested GBS testing, after my cousin's child suffered a severe GBS infection.

I used Midwifery: Community-Based Care During the Childbearing Year by Walsh, 2001, and the ol' standby, Williams Obstetrics: 20th Edition, 1997....a newer one is out by now, for sure.

One thing that I liked about Williams is that a dozen studies, with their results, were briefly cited and discussed in the textbook, "because of confusion, conflicting opinions, and lack of definitive data, there has been no universal approach to GBS screening and treatment."

Well, now ACOG has agreed to the treatment guidelines that the AAP had at the time of printing (1997) which is: screen everybody. At that time, ACOG was using their 1992 guideline which was because of the high colonization rate combined with a low attack rate, it was deemed "not cost effective" to screen all mothers. AAP said screen everybody, and treat colonized mothers with risk factors during labor. (I can't tell from my notes if that means: treat all colonized mothers AND treat those with risk factors, or treat colonized mothers WITH risk factors.)

Some studies cited from Williams, to support their clain that there is no universal approach to treatment:

study by Towers & colleges, 1996: only 1/3 of the women w/ risk factors actually recieved treatment

study by Parkland Hosptial, 1980: neonates got the penecillin the strep incidents went down, but the infection/mortatlity by penecilin-resistant nonstrep organizms went up

study by Boyer & Gotof, 1986: randomized intrapartum & neonatal ampicillin w/ colonized moms decresase in neonatal colonization (NOT ILLNESS--colonization) it was 9% instead of 51% colonized, and early onset sepsis (yes the illness) was 0% instead of 6%.


1) What is the rate of infection in newborns born to mothers who are GBS positive but have NO OTHER RISK FACTORS (no PROM, no pre-maturity, no fever in labor)?
according to Williams, the attack rate (that's what you're asking) is 1-2 per 1000 of all births

10 per 1000 for colonized mothers
40 per 1000 w/ preterm labor/birth, prolonged ROM, fever
of these infected babies, there is a 25% mortality rate

50% of newborns born to a GBS carrying mother are colonized at birth. (They do not die, they are not sick, tho they are colonized.)

2) What is the rate of infection in newborns born to mothers who are GBS positive but DO have other risk factors?

40 per 1000 w/ preterm labor/birth, prolonged ROM, fever
of these infected babies, there is a 25% mortality rate (from 1997 Williams)

3) CDC materials say the medication is most effective given at least 4 hours before birth. What's the curve on the reduction of effectiveness (i.e., how effective is it at 4 hours vs. 2 hours vs. 1 hour?

excellent question, I don't know.....and I feel like I know a few moms that "only got one bag of IV abx before the baby was born" and two bags are recommended.

4) What is the rate of fatal infection (not limited to GBS infection) in newborns born to GBS+ mothers who are treated with IV abx during labor?
another great question...there has to be a study out there somewhere...reminds me of the 1980 Parkland Hospital study I mentioned above

I am coming to the conclusion that GBS is a big ol' bugaboo.

AND WHY IS THERE NO STUDY ABOUT THE FREQUENCY OF VAGINAL EXAMS WITH BROKEN BAG OF WATERS AND GBS INFECTION?!?!?!

The introduction of bacteria and germs into the uterus via sterile vaginal exams by RNs and OBs is a HUGE PROBLEM if you ask me. It's not WOMEN'S faults or problems, if it's the frequent vaginal exams pushing GBS bacteria into wombs. I think routine GBS screening is another way to disempower women and set the stage for "your body is just out to KILL the baby" nonsense (just like those 'you're going to get a c-sec if you don't progress' threats are nonsense.)

here we go with some numbers--if you read summaries of what the CDC says instead of reading the resource at the CDC the numbers are inflated.. I don't know why but I have discussed this with other midwives eariler this year. here are a few posts
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the risk when abx is not given is 1.5/1000 for early onset
and the risk with abx is about .5/1000 probably more like .6 or.7/1000

this is from the national policy statement from the CDC and they update it

here is the web address-- I go to the site for professionals they have number crunched the studies and reviewed them-- even the more recent ones-- take a read
http://www.cdc.gov/groupBstrep/
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here is a statement from an epidemology journal you can read the entire article free at this address-- it is interesting that England has had a similar low rate at about the same time with out the same screening methods- also there have been past ebbs in GBS disease states....

http://ije.oxfordjournals.org/cgi/content/full/33/1/2

Changes in the incidence of early onset GBS disease

In the US, the risk of mother to child transmission and the incidence of early onset GBS disease were declining before screening for maternal GBS infection was introduced in the early 1990s. The incidence of early onset GBS disease fell from 2-3/1000 live births in the 1970s?1980s, to 1.4-1.8/1000 in 1990.13 Although the prevalence of maternal colonization remained stable at 20-25% during this period,3 it is not known whether the intensity of maternal colonization was diminishing, as might be expected with improved access to health care for high risk groups and improved management of urinary tract or other infections during pregnancy. Screening for GBS and intrapartum prophylactic antibiotics undoubtedly contributed to further decline in the incidence of early onset GBS disease during the 1990s, which stabilized at 0.2 to 0.5/1000 live births in the mid to late 1990s.14-25 In contrast, the incidence rate for late onset disease did not change over the 1990s remaining at approximately 0.4/1000 live births.13,26 In the UK, a study in Oxford from 1985 to 1996,27 and a recent national surveillance study in 2000-2001,28 reported incidence rates of early onset GBS disease (defined as septicaemia, pneumonia, or meningitis before 7 days of age) of 0.5/1000 live births, similar to the US, despite the lack of screening in the UK.

other factors - as others have said preterm infants are at greater risk
PROM in colonized women presents a greater risk
the bigger the colonies the greater the risk...
GBS UTI or colonization of the urinary tract is considered to be highly colonized and a greater chance of causing an infection(sorry but I don't have the studies at hand- my computer crashed a week ago and I don't have most of my info any more, probably can be found via references at the CDC or PUB MED)
other things like type B blood is at higher risk

Pediatrics. 1978 Oct;62(4):504-9.

Maternal ABO blood group type B: a risk factor in the developement of neonatalgroup B streptococcal disease.
Regan JA, Chao S, James LS.

In a prospective study of maternal genital colonization with group B
streptococci (GBS) at the time of delivery, epidemiological data, including
blood type (ABO group), were recorded for the 1,062 patients studied. Blood type B was found in a statistically significant higher proportion of patients
colonized with GBS (28%) compared with the total population (16.4%) (P less than .005, X2 = 8.43). Women with blood type B were twice as likely to be colonized as those with types O or A. ( this abstract I shortened to be less than 100 words the whole abstract can be found at pub med)

PMID: 362365 [PubMed - indexed for MEDLINE]
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internal monitor according to a Canadian study increases risks as does the number of vaginal checks done in labor.