To Test or Not To Test . . .

This coming Thursday I have an appointment with my backup OB for my Group B Strep (GBS) swab. This test is part of the normal pre-natal package for women in the United States. Somewhere between 35 and 37 weeks you get your vagina and perineum swabbed and the sample is sent off to the lab to be cultured for GBS. If it comes back negative its no big deal. If it comes back positive then there is a chance that you can pass GBS to your baby during delivery which can result in neonatal GBS disease. The standard treatment for a GBS positive woman is intervenous antibiotics during labor. The idea is that the antibiotics will pass through the placenta and reduce the chance of infection for the baby.

So, whats the big deal? Why not just get the test?

Its become apparent that I can't take any medical advice at face value these days. It seems I have this odd urge to look things up for myself. I went to the CDC website to get some facts about GBS. Here is what they say in their "Protect Your Baby from Group B Strep!" pamphlet:

• Your baby can get very sick and even die if you are not tested and treated [for GBS].
• In the United States, about 1 in 4 women carry this type of bacteria.
• Each time you are pregnant, you need to be tested for GBS.
• The medicine to stop GBS from spreading to your baby is an antibiotic given during labor. The antibotic (usually penicillin) is given to you through an IV (in the vein) during childbirth. If you are allergic to penicillin, there are still other choices to help treat you during labor.
  

Basically, what this pamplet says is that 1 in 4 women (25%) carry a type of bacteria that can cause her baby to "get very sick and even die." Sounds pretty scary. But surely not every woman who is a GBS carrier gives birth to an infected baby? I went in search of some hard numbers from the CDC.

I found some in the GBS FAQ. Here are a few snipits from that page:

• Group B strep is the most common cause of life-threatening infections in newborns.
• In the year 2001, there were about 1,700 babies in the U.S. less than one week old who got early-onset group B strep disease. (authors note: GBS infections are categorized as early-onset [happening within the first week of life] and late-onset [anytime after the first week])
• Premature babies are more at risk of getting a group B strep infection, but most babies who become sick from group B strep are full-term.
• Most early-onset group B strep disease in newborns can be prevented by giving pregnant women antibiotics (medicine) through the vein (IV) during labor.

That really didn't help much. It didn't tell me much more than the first CDC publication. It basically reinforced the idea that GBS is dangerous and scary but it can be taken care of with antibiotics. The fact that in 2001 there were 1,700 babies in the U.S. who were diagnosed with early-onset GBS disease doesn't help much either. It doesn't tell me how bad it was, if these babies died, or what the long-term outcomes were. Maybe my problem was that I was looking at information designed for the "general public." I decided to delve into the information for "professsionals." Here are some facts from the GBS Technical Overview for hospitals and healthcare providers:

• The rate of early-onset infection has decreased from 1.7 cases per 1,000 live births (1993) to 0.5 cases per 1,000 live births (2000). Since active prevention began in the mid 1990s, the rate of group B strep disease among newborns in the first week of life has declined by 70%. . . Since 1998, the incidence of early-onset disease has begun to plateau.
• Death occurs in 5% of infants

Now we actually have something. Prior to implementing universal screening and antibiotic prophalaxis there were 1.7 cases per 1,000 live births. By their numbers that means in a population of 1,000,000 infants there were 1,700 cases of early-onset GBS. Of that 1,700, 5% would have died. Thats 85 dead babies. That number doesn't tell us about those that were permanently harmed, but it at least gives us the death rate of GBS infection provided you don't do anything about it.

Thats the story from the CDC. GBS is scary and deadly but thanks to CDC guidelines they have been able to reduce the risk and save countless babies from death or disability. Now we all know that the United States lags behind several other countries in infant mortality rate and since GBS must be a contributing factor in those numbers, I thought I would check out how other countries are dealing with it. I chose the UK because we have similar populations and they rank 14 or 15 spots ahead of us in infant mortality.

My first stop was the Royal College of Obstetricians and Gynocologists. I found out that they had an informational pamphlet just like the CDC. Its designed for the "general public." Here are a few gems from that publication:

• About a quarter of pregnant women in the UK carry GBS in their vagina (same as the U.S.)
• GBS carriage is not routinely screened for during pregnancy in the UK. (!?)
• Out of every 2000 newborn babies in the UK and Ireland, only one is diagnosed with neonatal GBS, but it can be very serious. (thats the same as the U.S.'s numbers with our active prevention policy)
• Around one baby dies out of every ten who are diagnosed.
• Currently the evidence suggests that screening all pregnant women routinely would not be beneficial overall. You can be tested privately for GBS but the RCOG does not recommend this because a positive test may possibly result in unnecessary and potentially harmful interventions.
• It is important to be aware that a negative swab test does not guarantee that you are not a carrier of GBS.
• One of the potential harms of screening for GBS carriage during pregnancy is that large numbers of women would be given antibiotics during labour. The possible risks of this are: death or serious injury to a very few women from an allergic reaction(anaphylaxis) to the antibiotics, [and] strains of bacteria becoming resistant to antibiotics.

Wow. In the UK they have a lower rate of both infection and death from GBS and they don't routinely screen or treat for it. In fact, they think the risk of giving a large population of women antibiotics during labor could cause more problems than it fixes. I went looking for something that could put this together for me. I found an article on GBS at a mainstream women's health website that serves the UK. In the article the author states that "In the UK, ENGBSS [Early Neonatal Group B Streptococcal Septicaemia] occurs in 0.3/1000 neonates. In the US it is 3/1000." Because of this, "The difference in numbers between the US and UK mean that it may be worthwhile screening for this bacteria in the US, whereas in the UK because of its rarity, screening is unlikely to have a significant impact on neonatal deaths." Ok so, in both countries 1 in 4 women or 25% of them, have GBS present in their systems. Why then is the infection rate so different? Why are American women more likely to transmit GBS to their infants? The only thing I could find was in the Gentle Birth archives where an anonymous midwife states:

Any caregiver can introduce GBS also. I have watched docs and midwives when they do vaginals. They lube up and then do this little wipe of the vulva with their fingers (almost like foreplay) to lube up the woman. During that wipe they can easily pick up GBS and insert it with their fingers. And it is not unusual for anyone who has delivered in hospital to have GBS.

As everyone knows, docs do vaginals on the first visit of a pregnancy (for pelvimetry and STD checks). I believe that with that first vaginal they can introduce GBS to the cervix and all too often do.

If a caregiver is going to do a vaginal in early pregnancy (& even in late) then the vulva should be wiped first with a microbial swab.

Far better to avoid GBS then have to treat it.

Now that is far from scientific, but it makes sense. We know that every vaginal exam increases the risk of infection in any case. We also know that use of internal monitors provide a direct line into the uterus for bacteria. Its posssible that the over-medicalized maternity system in the US is partially responsible for the increased rate of GBS transmission. However, I have yet to find any scientific literature that addresses the discrepencies between the US and the UK. I am not positive that the birth system in the UK is any less medicalized than the US's, however I do know that midwives are more available and that they are less likely to engage in excessive vaginal exams or internal monitoring than are obstetricians.

The main thing that struck me about the UK policy was its view on antibiotics. The policy makers across the pond cite the concern that over use of antibiotics will result in resistant strains, as well as the concern about adverse reactions. What does all of this antibiotic use do? I found an article on MedScape (you have to register to read it, but registration is free) about GBS. It pretty much follows the narrative of the CDC but towards the end, the editor notes:

No strategies exist to prevent late-onset disease, although more than half of reported cases of neonatal GBS disease now occur during the late-onset period. In addition, concern continues among health officials that widespread intrapartum antimicrobial use might delay, rather than prevent, GBS disease onset, resulting in increased rates of late-onset disease. No evidence exists to suggest an increase; however, careful monitoring of disease trends remains a priority. (emphasis mine)

Thats pretty interesting. Its possible that giving antibiotics to all GBS carrying women is only delaying the infection until past the first week of life. Other studies I've found have suggested that widespread prophalactic antibiotic use for GBS women is resulting in antibiotic resistant infections from other sources. Another source found that more than one-third of GBS infections of the most common strain were resistant to the antibiotics used most often to treat the infection. Thats frightening. More superbugs. Then one has to look at the research showing that use of antibiotics by both mother and child increases the risk of things like allergies, eczema, and asthma. The choice starts to get more difficult than it was in the beginning when all I knew was that the CDC says GBS is scary and deadly.

So what is a woman to do. There are a few choices:

1. Get the test and take the recommended action
2. Don't take the test and wait until labor and see if any of the risk factors appear. Both the U.S. and the U.K. use the same guidelines for women in labor who are of unknown GBS status. If the woman has prolonged rupture of membranes (>18 hours), runs a fever (over 100.4), has had a previous baby with GBS disease, or has gone into labor before 37 weeks, she is considered at higher risk for transmitting GBS to her baby. The decision to treat with antibiotics can be made at that time.
3. Get the test and use alternative treatments like vaginal washing during labor if GBS positive.
4. Do absolutely nothing and if the baby presents with symptoms (fever, difficulty feeding, lethargy, difficulty breathing) any time after birth then seek immediate medical attention.

Knowing all of this, I'm still not sure what I'm going to do. I do know a few things. I know that if I take the test and it comes back positive, then I will refuse prophylactic antibiotics in labor. I am allergic to penicillin, ampicillin, clindamycin, erythromycin, and cipro. That pretty much covers the antibiotics available. In the rare event I have an infection that needs antibiotics I can only take bactrim and tetracycline, both of which are not recommended in pregnancy. I am very selective about when I use antibiotics because I'm slowly running out of options. I also have fairly severe asthma and other allergies. I've been doing everything I possibly can during this pregnancy to reduce the chances my child will go through what I've been through. The risks of using antibiotics during labor in my case are fairly high.

Given that I know I wont treat prophylactically if a positive result comes back, then whats the point in taking the test? I am having a home birth. In the event I present with a fever or prolonged rupture of membranes, those would be indications to transfer. Once at the hospital we can inform the attending of my unknown GBS status and I can be treated from there. I have an appointment with my midwife tomorrow and we'll discuss all of this at length. I'm not willing to do nothing. I'm not going to risk the life of my child. I think I would be more comfortable without the test and then treating if signs arise. I'm always skeptical of any medical recommendation that says "we should do this one thing to all of the people, all of the time."

I would really appreciate it if this post was spread around. I would like as much input on this subject as possible. Send me studies, criticise my logic, help me move on to a more perfect decision. I'll let everyone know what the midwife says about it tomorrow.

Just a disclaimer: I am not a medical professional, nor am I a statistician. None of this is designed to give anyone advice, its just an example of the thought process of where I'm going with my decision and how I got here. I'm still going to discuss all of this with my midwife and backup OB so we can decide what the safest course of action is. You, as a reader should do the same. Look at the available evidence and then work with your health care providers to have the safest, healthiest birth possible for you and your child.